This document presents a model for a vortex induced vibration (VIV) based hydrokinetic energy converter. It discusses the working principle and advantages of VIV energy conversion. Key parameters in the VIV phenomenon like natural frequency, reduced velocity, Reynolds number and Strouhal number are defined. Equations to characterize the fluid-structure interaction and determine dynamic response, lift force, power extracted, and efficiency are formulated. Physical features affecting the mathematical model like stagnation point, separation point, boundary layer and shear layer are also discussed. The model aims to predict dynamic response and power output to optimize energy extraction from slow-moving water currents.
Study of flow induced vibration of a circular cylindrical structureLahiru Dilshan
This document summarizes a student's study of flow induced vibration of a circular cylindrical structure. It includes calculations of the cylinder's properties and natural frequencies. It then discusses practical applications of vortex induced vibration including failures of structures like bridges. It notes multibody effects are important in applications like heat exchangers where multiple tubes can vibrate together. Methods for suppressing vortex induced vibration on cylinders are also listed.
Energy generation from vortex induced vibrations reporteor20104
This document discusses energy generation from vortex induced vibrations of bluff bodies in fluid flows. It describes how vortices form behind bluff bodies at certain flow speeds, creating periodic lift forces that can induce structural vibration. This vibration can be harnessed to extract energy through mechanisms attached to vibrating structures. Specifically, at certain flow speeds vortex shedding frequency locks in with the structure's natural frequency, amplifying vibrations and making more energy available for harvesting. The document provides theoretical background on vortex formation, shedding frequency, lock-in phenomena, and the effect of boundary gaps near structures.
Vortex induced vibratio ns aquatic clean energy converter vivace- shazShaz M Rahath
The VIVACE is an aquatic clean energy converter that generates power from vortex induced vibrations. It consists of horizontal cylinders that hang across flowing water and are free to move vertically, holding magnets inside guideways containing metal coils. As vortices form on the cylinders in the current, they vibrate and the magnets inside induce power in the coils. The VIVACE is advantageous because water has much higher energy density than air, allowing it to generate large amounts of power at low costs using small, unobtrusive structures that do not disrupt the environment or wildlife.
This document discusses energy harvesting from natural fluid flows using vortex shedding. Vortex shedding is the oscillating flow that occurs behind bluff bodies in a fluid stream, and can be harnessed to generate energy. The document proposes that enhancing vortex shedding could provide clean, renewable energy from ocean currents and tidal flows. While more research is needed, vortex energy harvesting has the potential to meet a significant portion of global energy needs in a way that is more powerful, renewable and low-cost than existing wind and hydro technologies.
This document discusses various technologies for producing energy from ocean waves. It begins with an introduction that outlines renewable and non-renewable energy sources. It then discusses wave energy specifically, noting that it is renewable and can reduce greenhouse gas emissions. The document outlines different types of wave energy technologies including oscillating water columns, oscillating body systems, fully submerged systems, and overtopping converters. It also discusses power equipment like hydraulic turbines. The document concludes by noting that while wave energy has advantages like being renewable and environmentally friendly, developing commercial wave energy systems has proven difficult and expensive due to testing and maintenance costs.
Wave power is the process of capturing the kinetic energy of ocean surface waves to generate electricity or do other work. Waves are formed by wind transferring energy to water. Factors like wind speed, duration, and distance traveled (fetch) determine wave size. Several technologies have been developed to harness wave power, including wave profile devices, oscillating water columns, and wave capture devices. Wave power is a renewable resource with advantages like being pollution-free and predictable, but challenges include high costs and only being available near coastlines. The first wave power patent was filed in 1799, and research and development has increased efforts to commercialize the technology.
The document discusses wave energy technology. It describes three main categories of wave energy converters: oscillating water columns that use air pockets to drive turbines; oscillating body converters that use wave motion to generate electricity; and overtopping converters that use reservoirs to drive turbines. More than 100 pilot and demonstration projects exist worldwide but only a handful are close to commercialization. The document estimates the potential cost of electricity from wave energy and barriers to its development and deployment.
1. The presentation discusses wave energy converter technology and reviews a specific article on the topic.
2. It is presented by five students and focuses on defining different types of wave energy converters including attenuators, point absorbers, and terminators.
3. The conclusion evaluates the current status and challenges of wave energy converter concepts and technologies.
Study of flow induced vibration of a circular cylindrical structureLahiru Dilshan
This document summarizes a student's study of flow induced vibration of a circular cylindrical structure. It includes calculations of the cylinder's properties and natural frequencies. It then discusses practical applications of vortex induced vibration including failures of structures like bridges. It notes multibody effects are important in applications like heat exchangers where multiple tubes can vibrate together. Methods for suppressing vortex induced vibration on cylinders are also listed.
Energy generation from vortex induced vibrations reporteor20104
This document discusses energy generation from vortex induced vibrations of bluff bodies in fluid flows. It describes how vortices form behind bluff bodies at certain flow speeds, creating periodic lift forces that can induce structural vibration. This vibration can be harnessed to extract energy through mechanisms attached to vibrating structures. Specifically, at certain flow speeds vortex shedding frequency locks in with the structure's natural frequency, amplifying vibrations and making more energy available for harvesting. The document provides theoretical background on vortex formation, shedding frequency, lock-in phenomena, and the effect of boundary gaps near structures.
Vortex induced vibratio ns aquatic clean energy converter vivace- shazShaz M Rahath
The VIVACE is an aquatic clean energy converter that generates power from vortex induced vibrations. It consists of horizontal cylinders that hang across flowing water and are free to move vertically, holding magnets inside guideways containing metal coils. As vortices form on the cylinders in the current, they vibrate and the magnets inside induce power in the coils. The VIVACE is advantageous because water has much higher energy density than air, allowing it to generate large amounts of power at low costs using small, unobtrusive structures that do not disrupt the environment or wildlife.
This document discusses energy harvesting from natural fluid flows using vortex shedding. Vortex shedding is the oscillating flow that occurs behind bluff bodies in a fluid stream, and can be harnessed to generate energy. The document proposes that enhancing vortex shedding could provide clean, renewable energy from ocean currents and tidal flows. While more research is needed, vortex energy harvesting has the potential to meet a significant portion of global energy needs in a way that is more powerful, renewable and low-cost than existing wind and hydro technologies.
This document discusses various technologies for producing energy from ocean waves. It begins with an introduction that outlines renewable and non-renewable energy sources. It then discusses wave energy specifically, noting that it is renewable and can reduce greenhouse gas emissions. The document outlines different types of wave energy technologies including oscillating water columns, oscillating body systems, fully submerged systems, and overtopping converters. It also discusses power equipment like hydraulic turbines. The document concludes by noting that while wave energy has advantages like being renewable and environmentally friendly, developing commercial wave energy systems has proven difficult and expensive due to testing and maintenance costs.
Wave power is the process of capturing the kinetic energy of ocean surface waves to generate electricity or do other work. Waves are formed by wind transferring energy to water. Factors like wind speed, duration, and distance traveled (fetch) determine wave size. Several technologies have been developed to harness wave power, including wave profile devices, oscillating water columns, and wave capture devices. Wave power is a renewable resource with advantages like being pollution-free and predictable, but challenges include high costs and only being available near coastlines. The first wave power patent was filed in 1799, and research and development has increased efforts to commercialize the technology.
The document discusses wave energy technology. It describes three main categories of wave energy converters: oscillating water columns that use air pockets to drive turbines; oscillating body converters that use wave motion to generate electricity; and overtopping converters that use reservoirs to drive turbines. More than 100 pilot and demonstration projects exist worldwide but only a handful are close to commercialization. The document estimates the potential cost of electricity from wave energy and barriers to its development and deployment.
1. The presentation discusses wave energy converter technology and reviews a specific article on the topic.
2. It is presented by five students and focuses on defining different types of wave energy converters including attenuators, point absorbers, and terminators.
3. The conclusion evaluates the current status and challenges of wave energy converter concepts and technologies.
This document discusses wave power conversion systems for electrical energy production. It describes how ocean waves are generated by wind and outlines different types of wave power mechanisms including oscillating water columns, underwater pneumatic systems, and offshore devices like the Pelamis wave energy converter. The Pelamis is highlighted as the world's first commercial scale wave power device, consisting of connected floating sections that capture wave energy which is then converted to electricity via hydraulic motors.
The document summarizes different methods for harnessing wave power as an alternative energy source. It describes four main types of wave power station designs: point absorbers consisting of underwater buoys that move with wave action; oscillating water columns where waves pressurize air in a column to turn a turbine; overtopping devices that capture water from waves above the mean height in a reservoir to release through turbines; and attenuators which are long floating structures that flex with differing wave heights along their length to drive energy converters. The challenges of wave power include corrosion, efficiently converting wave motion to electricity, and high production costs compared to other renewable sources.
The document summarizes wave power as an alternative energy source. It discusses how wave energy forms from wind blowing across water, and how different wave energy converters can capture energy from waves. Specifically, it describes point absorbers and attenuators as wave profile devices, oscillating water columns as a type of converter that uses air pressure, and wave capture devices that lift water into a reservoir. The document also notes India's wave power potential and ongoing projects, and discusses some environmental impacts but also benefits of wave power installations.
This document provides an overview of wave power and wave energy technologies. It begins with an introduction to wave energy and where it is successfully harnessed. It then covers the history, resource potential, and variability of ocean waves. The document describes wave motion and velocity. It defines wave energy and power concepts. The bulk of the document examines different ocean wave energy technology approaches, including attenuators, terminators, oscillating water columns, point absorbers, and overtopping devices. It provides examples like the Pelamis wave energy converter. The document concludes with advantages and disadvantages of wave power.
Wave energy originates from the sun heating the earth's surface and creating winds that transfer energy to ocean waters, generating waves. As waves travel vast distances across oceans, the longer and stronger the wind blows, the higher, longer, faster, and more powerful the waves become. Three main types of wave energy conversion devices interact with ocean waves to harness the kinetic energy for electricity: offshore devices dealing with swell, near shore devices capturing maximum wave amplitude, and embedded devices receiving breaking waves along shorelines. Examples of technologies include Pelamis machines that generate power from wave rolling motions and oscillating water columns that use wave pumping of air to drive turbines. Significant wave energy resources exist off coasts between 30-60 degree latitudes, and
A wave-to-wire model of ocean wave energy conversion system using MATLAB/Simu...Jakir Hossain
Renewable energy sources, unlike the conventional combustible fuels, are naturally distributed and extensively available in a boundless manner all over the world in different forms. Here, in this paper, authors elucidate the scopes and opportunities of the ocean wave to develop a low-cost, environmental friendly, and sustainable electrical power generation system. At the present time most technological modernizations aimed at exploiting such resources are at early stage of development, with only a handful of devices close to be at the commercial demonstration stage. None of them, though, operates converting the wave energy contents at its very origin: the orbital motion of water particles right below the ocean surface. The Sea spoon device catches the kinetic energy of ocean waves with favorable conversion proficiency, according to specific "wave-motion climate". In this letter, authors illustrate a possible methodology of converting this naturally exorbitant energy with efficient conversion methodology and simulating the conversion environment with MATLAB/Simulink platform.
This document discusses wave energy as a renewable source of energy. It explains that wind energy transfers to ocean waves, and wave energy machines like turbines and buoys can capture this energy from waves and tides to generate pollution-free electricity. While wave energy technology is still developing, it is estimated that fully utilizing wave energy could satisfy around 40% of the world's total energy needs. The main ways to capture wave power are surface devices, underwater devices, and reservoirs. The document also describes different types of wave energy converters including attenuators, point absorbers, submerged pressure differential devices, overtopping devices, and oscillating wave surge converters.
The document discusses the potential for wave power as a renewable energy source. It notes that the sea provides abundant wave energy that can be harnessed through various wave energy conversion techniques currently under development. The Basque coast is highlighted as an ideal location for developing and testing wave power technologies due to its wave energy resources and industrial base in the energy and shipbuilding sectors. The region has demonstrated leadership through projects like the Mutriku wave power plant and bimep wave energy test site. Collaboration between industry, research centers, and government in the Basque Country has supported significant progress in wave energy research, development and testing.
Wave Power Conversion Systems for Electrical Energy ProductionLeonardo ENERGY
This document discusses wave power conversion systems for electrical energy production. It provides an overview of where ocean waves come from and characteristics of waves like wavelength, height, period, and speed. The global resource of wave power is estimated at around 2 terawatts, with areas between latitudes 30-60° in both hemispheres having the most wave activity. Conversion mechanisms discussed include oscillating water columns, underwater pneumatic systems, and offshore oscillating bodies like the Pelamis wave energy converter. The Pelamis is highlighted as the first commercial scale machine to generate electricity from offshore waves.
The document summarizes wave energy and its potential as a renewable energy source. It discusses how waves are generated by wind, the history of wave energy technology development, and the main types of wave energy conversion systems including attenuators, point absorbers, oscillating water columns, and overtopping devices. It provides examples of current wave energy projects in locations like Scotland, Portugal, and Australia. It also discusses Egypt's potential for wave energy and the challenges still facing the widespread commercialization of wave power, such as high costs, environmental impacts, and ensuring device reliability in harsh ocean conditions.
This document summarizes different aspects of wave energy technology. It describes how wave energy works by capturing the energy of ocean surface waves. It then discusses the history of wave energy technology and some prominent pioneers. The document goes on to explain different types of wave energy conversion devices classified by their installation site, principle of operation, and energy capture system. Specific devices like overtopping, oscillating water columns, point absorber buoys, and surface attenuators are described in detail. It concludes by noting that while wave energy systems are currently small, technologies are developing to harness more power from ocean waves.
This document discusses different types of wave energy conversion devices classified by their mode of operation, including submerged pressure differential devices, oscillating wave surge converters, oscillating water columns, and overtopping devices. It notes that while the method of energy capture varies, one major challenge for wave energy converters is how to drive electrical generators as heaving and nodding devices are incompatible with conventional rotary machines and require a transmission system.
Theoretical based Analysis on finding the potential of Wave Energy in Pakistan, based on data gathered about wind-wave characteristics at Karachi Sea Shore.
The document summarizes various wave power conversion systems for producing electrical energy from sea waves. It describes how sea waves are formed and quantifies the power associated with waves. Several devices are then described that extract mechanical energy from waves including oscillating water columns, the Pelamis system, and the Wave Dragon system. The Pelamis system is discussed in more detail, as it consists of articulated cylinders that move with waves to pump hydraulic fluid and drive electric generators. The document concludes that wave power could make a major contribution to renewable energy production.
Aquamarine Power has developed a wave energy converter called Oyster, which is the world's largest at 40MW capacity. It was installed at EMEC in Scotland. Previously the largest was only 2.4MW in the UK. Oyster uses the motion of a hinged flap from wave movement to drive hydraulic pistons, which pressurize water to turn a turbine and generator on shore to produce electricity in an efficient hydro-electric process. Oyster is estimated to operate efficiently for 15 years and provide reliable, eco-friendly energy from the ocean.
This document provides an overview of various renewable ocean energy technologies, including wave, tidal, and ocean thermal energy. It discusses concepts such as how wave and tidal energy can be harnessed through devices that convert the kinetic or potential energy of ocean currents and waves into rotational or hydraulic motion. Examples of existing tidal power plants like the one in Rance River, France are also summarized.
Sea waves have high energy densities, the highest among renewable energy sources with the natural seasonal variability of wave energy following the electricity demand in temperate climates securing energy supplies in remote regions.
Wave energy has significant potential as a renewable energy source. Ocean waves are generated by wind blowing across the water surface. The amount of energy in a wave depends on wind speed, duration, and the distance over which the wind blows known as fetch. Worldwide, the potential for wave energy has been estimated at over 2,000 terawatt hours per year, which is around 10% of current global electricity consumption. Several types of devices have been designed to capture the energy from ocean waves, such as the Wave Dragon which uses a reservoir and low-head turbines to convert wave motion into electricity. Wave energy offers a large, renewable resource but development has been limited by high costs and the need for suitable coastal locations with consistently strong wave
Wave energy comes from ocean waves that are caused by wind blowing over the surface of the water. There is a lot of energy in ocean waves that can be harnessed through wave power devices. One method of capturing wave energy works similar to a swimming pool wave machine but in reverse, using the motion of waves to drive air in and out of a chamber to power a turbine and generator. While wave energy is a renewable source that produces no emissions, a consistent wave source is required and devices must be able to withstand rough ocean weather.
The proposed wave energy converter consists of a floating tube filled with water and power units inside. As waves pass, the water level inside the tube fluctuates up and down, causing buoys attached to the power units to move. This motion is converted to electrical energy via gear systems and generators. The design aims for low cost production and maintenance to produce electricity at around €0.05/kWh. Key aspects are its modular structure, ability to withstand storms by sinking below waves, and potential organization into zig-zag farms for efficient energy capture and transmission. Experimental testing is needed to validate the power generation capabilities and viability of the concept.
Analysis of Organophosphate Pesticides Residue on Crops in Abakaliki, Ebonyi ...IOSR Journals
This document analyzes organophosphate pesticide residue found on pumpkin crops in Abakaliki, Ebonyi State, Nigeria. Samples of pumpkin leaves were collected 3 days after being sprayed with organophosphate pesticides and analyzed using gas chromatography. Sample A contained dioxabenzeofos and phenanthrene. Sample B contained chlorethoxyfos, oxydeprofos, sulfotep, phenanthrene, and dioxabenzofos. Sample C contained chlonethoxy fos, oxydeprofos, sulfotep, phenanthrene, and dioxabenzofos. All residues were below the LD50 toxicity range for organophosphates. The
Investigation of Reducing Process of Uneven Shade Problem In Case Of Compact ...IOSR Journals
This document investigates reducing uneven shade problems in compact single jersey cotton knit fabrics dyed with turquoise reactive dyes. Scanning electron microscopy shows that stripping and scouring combined increases fabric porosity compared to scouring alone, allowing better dye penetration. Color measurement testing finds that combining stripping and scouring results in more consistent dye absorption and less uneven shading than separate processes, with CMC ΔE values below 1 indicating acceptable color matches. In conclusion, performing stripping and scouring simultaneously on compact single jersey fabrics before dyeing with turquoise reduces uneven dyeing compared to conventional pretreatment methods.
This document discusses wave power conversion systems for electrical energy production. It describes how ocean waves are generated by wind and outlines different types of wave power mechanisms including oscillating water columns, underwater pneumatic systems, and offshore devices like the Pelamis wave energy converter. The Pelamis is highlighted as the world's first commercial scale wave power device, consisting of connected floating sections that capture wave energy which is then converted to electricity via hydraulic motors.
The document summarizes different methods for harnessing wave power as an alternative energy source. It describes four main types of wave power station designs: point absorbers consisting of underwater buoys that move with wave action; oscillating water columns where waves pressurize air in a column to turn a turbine; overtopping devices that capture water from waves above the mean height in a reservoir to release through turbines; and attenuators which are long floating structures that flex with differing wave heights along their length to drive energy converters. The challenges of wave power include corrosion, efficiently converting wave motion to electricity, and high production costs compared to other renewable sources.
The document summarizes wave power as an alternative energy source. It discusses how wave energy forms from wind blowing across water, and how different wave energy converters can capture energy from waves. Specifically, it describes point absorbers and attenuators as wave profile devices, oscillating water columns as a type of converter that uses air pressure, and wave capture devices that lift water into a reservoir. The document also notes India's wave power potential and ongoing projects, and discusses some environmental impacts but also benefits of wave power installations.
This document provides an overview of wave power and wave energy technologies. It begins with an introduction to wave energy and where it is successfully harnessed. It then covers the history, resource potential, and variability of ocean waves. The document describes wave motion and velocity. It defines wave energy and power concepts. The bulk of the document examines different ocean wave energy technology approaches, including attenuators, terminators, oscillating water columns, point absorbers, and overtopping devices. It provides examples like the Pelamis wave energy converter. The document concludes with advantages and disadvantages of wave power.
Wave energy originates from the sun heating the earth's surface and creating winds that transfer energy to ocean waters, generating waves. As waves travel vast distances across oceans, the longer and stronger the wind blows, the higher, longer, faster, and more powerful the waves become. Three main types of wave energy conversion devices interact with ocean waves to harness the kinetic energy for electricity: offshore devices dealing with swell, near shore devices capturing maximum wave amplitude, and embedded devices receiving breaking waves along shorelines. Examples of technologies include Pelamis machines that generate power from wave rolling motions and oscillating water columns that use wave pumping of air to drive turbines. Significant wave energy resources exist off coasts between 30-60 degree latitudes, and
A wave-to-wire model of ocean wave energy conversion system using MATLAB/Simu...Jakir Hossain
Renewable energy sources, unlike the conventional combustible fuels, are naturally distributed and extensively available in a boundless manner all over the world in different forms. Here, in this paper, authors elucidate the scopes and opportunities of the ocean wave to develop a low-cost, environmental friendly, and sustainable electrical power generation system. At the present time most technological modernizations aimed at exploiting such resources are at early stage of development, with only a handful of devices close to be at the commercial demonstration stage. None of them, though, operates converting the wave energy contents at its very origin: the orbital motion of water particles right below the ocean surface. The Sea spoon device catches the kinetic energy of ocean waves with favorable conversion proficiency, according to specific "wave-motion climate". In this letter, authors illustrate a possible methodology of converting this naturally exorbitant energy with efficient conversion methodology and simulating the conversion environment with MATLAB/Simulink platform.
This document discusses wave energy as a renewable source of energy. It explains that wind energy transfers to ocean waves, and wave energy machines like turbines and buoys can capture this energy from waves and tides to generate pollution-free electricity. While wave energy technology is still developing, it is estimated that fully utilizing wave energy could satisfy around 40% of the world's total energy needs. The main ways to capture wave power are surface devices, underwater devices, and reservoirs. The document also describes different types of wave energy converters including attenuators, point absorbers, submerged pressure differential devices, overtopping devices, and oscillating wave surge converters.
The document discusses the potential for wave power as a renewable energy source. It notes that the sea provides abundant wave energy that can be harnessed through various wave energy conversion techniques currently under development. The Basque coast is highlighted as an ideal location for developing and testing wave power technologies due to its wave energy resources and industrial base in the energy and shipbuilding sectors. The region has demonstrated leadership through projects like the Mutriku wave power plant and bimep wave energy test site. Collaboration between industry, research centers, and government in the Basque Country has supported significant progress in wave energy research, development and testing.
Wave Power Conversion Systems for Electrical Energy ProductionLeonardo ENERGY
This document discusses wave power conversion systems for electrical energy production. It provides an overview of where ocean waves come from and characteristics of waves like wavelength, height, period, and speed. The global resource of wave power is estimated at around 2 terawatts, with areas between latitudes 30-60° in both hemispheres having the most wave activity. Conversion mechanisms discussed include oscillating water columns, underwater pneumatic systems, and offshore oscillating bodies like the Pelamis wave energy converter. The Pelamis is highlighted as the first commercial scale machine to generate electricity from offshore waves.
The document summarizes wave energy and its potential as a renewable energy source. It discusses how waves are generated by wind, the history of wave energy technology development, and the main types of wave energy conversion systems including attenuators, point absorbers, oscillating water columns, and overtopping devices. It provides examples of current wave energy projects in locations like Scotland, Portugal, and Australia. It also discusses Egypt's potential for wave energy and the challenges still facing the widespread commercialization of wave power, such as high costs, environmental impacts, and ensuring device reliability in harsh ocean conditions.
This document summarizes different aspects of wave energy technology. It describes how wave energy works by capturing the energy of ocean surface waves. It then discusses the history of wave energy technology and some prominent pioneers. The document goes on to explain different types of wave energy conversion devices classified by their installation site, principle of operation, and energy capture system. Specific devices like overtopping, oscillating water columns, point absorber buoys, and surface attenuators are described in detail. It concludes by noting that while wave energy systems are currently small, technologies are developing to harness more power from ocean waves.
This document discusses different types of wave energy conversion devices classified by their mode of operation, including submerged pressure differential devices, oscillating wave surge converters, oscillating water columns, and overtopping devices. It notes that while the method of energy capture varies, one major challenge for wave energy converters is how to drive electrical generators as heaving and nodding devices are incompatible with conventional rotary machines and require a transmission system.
Theoretical based Analysis on finding the potential of Wave Energy in Pakistan, based on data gathered about wind-wave characteristics at Karachi Sea Shore.
The document summarizes various wave power conversion systems for producing electrical energy from sea waves. It describes how sea waves are formed and quantifies the power associated with waves. Several devices are then described that extract mechanical energy from waves including oscillating water columns, the Pelamis system, and the Wave Dragon system. The Pelamis system is discussed in more detail, as it consists of articulated cylinders that move with waves to pump hydraulic fluid and drive electric generators. The document concludes that wave power could make a major contribution to renewable energy production.
Aquamarine Power has developed a wave energy converter called Oyster, which is the world's largest at 40MW capacity. It was installed at EMEC in Scotland. Previously the largest was only 2.4MW in the UK. Oyster uses the motion of a hinged flap from wave movement to drive hydraulic pistons, which pressurize water to turn a turbine and generator on shore to produce electricity in an efficient hydro-electric process. Oyster is estimated to operate efficiently for 15 years and provide reliable, eco-friendly energy from the ocean.
This document provides an overview of various renewable ocean energy technologies, including wave, tidal, and ocean thermal energy. It discusses concepts such as how wave and tidal energy can be harnessed through devices that convert the kinetic or potential energy of ocean currents and waves into rotational or hydraulic motion. Examples of existing tidal power plants like the one in Rance River, France are also summarized.
Sea waves have high energy densities, the highest among renewable energy sources with the natural seasonal variability of wave energy following the electricity demand in temperate climates securing energy supplies in remote regions.
Wave energy has significant potential as a renewable energy source. Ocean waves are generated by wind blowing across the water surface. The amount of energy in a wave depends on wind speed, duration, and the distance over which the wind blows known as fetch. Worldwide, the potential for wave energy has been estimated at over 2,000 terawatt hours per year, which is around 10% of current global electricity consumption. Several types of devices have been designed to capture the energy from ocean waves, such as the Wave Dragon which uses a reservoir and low-head turbines to convert wave motion into electricity. Wave energy offers a large, renewable resource but development has been limited by high costs and the need for suitable coastal locations with consistently strong wave
Wave energy comes from ocean waves that are caused by wind blowing over the surface of the water. There is a lot of energy in ocean waves that can be harnessed through wave power devices. One method of capturing wave energy works similar to a swimming pool wave machine but in reverse, using the motion of waves to drive air in and out of a chamber to power a turbine and generator. While wave energy is a renewable source that produces no emissions, a consistent wave source is required and devices must be able to withstand rough ocean weather.
The proposed wave energy converter consists of a floating tube filled with water and power units inside. As waves pass, the water level inside the tube fluctuates up and down, causing buoys attached to the power units to move. This motion is converted to electrical energy via gear systems and generators. The design aims for low cost production and maintenance to produce electricity at around €0.05/kWh. Key aspects are its modular structure, ability to withstand storms by sinking below waves, and potential organization into zig-zag farms for efficient energy capture and transmission. Experimental testing is needed to validate the power generation capabilities and viability of the concept.
Analysis of Organophosphate Pesticides Residue on Crops in Abakaliki, Ebonyi ...IOSR Journals
This document analyzes organophosphate pesticide residue found on pumpkin crops in Abakaliki, Ebonyi State, Nigeria. Samples of pumpkin leaves were collected 3 days after being sprayed with organophosphate pesticides and analyzed using gas chromatography. Sample A contained dioxabenzeofos and phenanthrene. Sample B contained chlorethoxyfos, oxydeprofos, sulfotep, phenanthrene, and dioxabenzofos. Sample C contained chlonethoxy fos, oxydeprofos, sulfotep, phenanthrene, and dioxabenzofos. All residues were below the LD50 toxicity range for organophosphates. The
Investigation of Reducing Process of Uneven Shade Problem In Case Of Compact ...IOSR Journals
This document investigates reducing uneven shade problems in compact single jersey cotton knit fabrics dyed with turquoise reactive dyes. Scanning electron microscopy shows that stripping and scouring combined increases fabric porosity compared to scouring alone, allowing better dye penetration. Color measurement testing finds that combining stripping and scouring results in more consistent dye absorption and less uneven shading than separate processes, with CMC ΔE values below 1 indicating acceptable color matches. In conclusion, performing stripping and scouring simultaneously on compact single jersey fabrics before dyeing with turquoise reduces uneven dyeing compared to conventional pretreatment methods.
This document presents a vibration analysis of a rotating composite beam using the dynamic stiffness matrix method. The dynamic stiffness matrix method, traditionally used for homogeneous beams, is applied to composite beams by determining the effective Young's modulus of the composite material. Natural frequencies of the rotating composite beam are calculated for different parameters like rotational speed, hub radius, and number of layers in the composite. Results show how the natural frequency is influenced by these various parameters. The dynamic stiffness matrix method is considered an advanced technique as it provides exact natural frequency and mode shape results without approximations.
This document summarizes a study that investigated the formulation of neem seed oil and jatropha seed oil with antimony dialkyldithiocarbohate (ADTC) additives for use as bio-based lubricants. Tribological tests were conducted using a four-ball tribometer to evaluate the lubricity performance of the two oil formulations. The results showed that the jatropha seed oil formulation had lower friction coefficients and better wear protection under the test conditions, indicating it performed better as a lubricant. The study concluded that jatropha seed oil with ADTC additives showed potential for use as an environmentally-friendly bio-based lubricant.
1) The document derives the equations describing the interaction forces between two identical cylinders spinning around their stationary and parallel axes in an ideal fluid.
2) It is found that the fluid velocity field can be determined by solving the Laplace equation, and that the pressure field can then be obtained from the velocity field using Bernoulli's equation.
3) By integrating the pressure around the surface of each cylinder, it is shown that the cylinders will repel or attract each other in inverse relation to their separation distance, depending on whether their directions of rotation are the same or opposite.
The document describes a new efficient shower water heater design that uses a novel heat transfer method. Key points:
- The design aims to significantly reduce power consumption compared to conventional electric water heaters by heating water in small volumes directly in the shower head rather than a large reservoir.
- Coiled heating elements housed in small tubes are placed inside the shower head openings so that only a few milliliters of water pass through and are heated at a time.
- This micro heating approach is expected to exponentially reduce the power needed compared to traditional systems that heat larger volumes of water at once.
- Other benefits may include lower hazards, portability, lighter weight, and enabling the use of small renewable power
This document summarizes a case study that used the Canadian Seismic Screening Method to evaluate 37 reinforced concrete buildings in Ahlat, Turkey. The screening method uses 8 parameters to calculate a Structural Index and Non-Structural Index for each building, which are then combined to determine a Seismic Priority Index. For the study in Ahlat, 14% of buildings were rated as low priority, 41% as medium priority, 35% as high priority, and 10% as very risky priority. The screening method provided a fast way to assess the seismic risk of numerous buildings and identify which should undergo more detailed evaluation.
Research Paper Selection Based On an Ontology and Text Mining Technique Using...IOSR Journals
This document proposes an ontology and text mining technique to select research papers. It involves 3 phases: 1) constructing a research ontology using keywords and frequencies from past papers, 2) classifying new papers based on ontology keywords, and 3) clustering papers in each domain using text mining and the K-means algorithm. The technique aims to better group papers and assign them to relevant reviewers by addressing limitations of keyword-based methods. It constructs a research ontology, classifies papers, clusters them based on textual similarities, and systematically assigns papers to reviewers.
This document summarizes a study that used artificial neural networks (ANNs) and the Multi-Layer Perceptron model (MLP) to predict the bearing capacities of steel driven piles in sandy soils. The ANN was trained on data from full-scale pile load tests, including pile length, diameter, soil elastic modulus, and soil friction angle as inputs. The output was pile bearing capacity. The study examined factors for effective ANN behavior, trained and tested the network, and analyzed the sensitivity of the inputs on the output capacity prediction.
This document discusses enhancing power system restoration in a restructured power system using hydrogen energy storage and a unified power flow controller. It proposes using a proportional-double integral controller optimized with a bacterial foraging algorithm for automatic generation control. The controller aims to improve power system restoration indices and reduce restoration time to improve reliability. Hydrogen energy storage and unified power flow control are introduced to provide fast response to load changes and improve power transfer limits to facilitate faster restoration.
This document summarizes a study on modifying bitumen used in road construction with waste plastics and crumb rubber. The study aims to determine which waste material (PET bottles or crumb rubber) can better modify bitumen properties when added in varying percentages. Marshall stability tests are conducted on bitumen concrete mixes containing 3-9% by weight of either PET bottles or crumb rubber added to the bitumen. The results of the stability tests are used to analyze how the waste materials affect the mechanical properties of the mixes and to identify the optimum percentage to achieve maximum strength.
The document describes the implementation of a fiber optic communication system using a developed computer program. It discusses the key components of a fiber optic system including the transmitter, fiber optic cable, and receiver. The transmitter converts an electrical input signal into an optical signal by modulating the output of a light source, such as a laser or LED. The fiber optic cable then carries this optical signal to the receiver. The computer program allows for modeling each of these components, including analyzing different transmitter circuit designs and light sources. It provides input and output forms to design an optical transmitter and model its performance parameters like rise time and data rate.
This document presents a study on using sliding mode control to regulate the speed of a DC motor. It begins with background on variable structure systems and sliding mode control. It then describes the mathematical model of a typical DC motor. The controller design section explains the sliding mode control approach, including defining a sliding surface and the control law. Simulation results are presented showing the motor speed and control voltage signal over time for different sliding mode controllers. The document concludes the sliding mode control technique provides robustness and can stabilize uncertain systems while rejecting disturbances.
This document presents the results of a study on the drying shrinkage of concrete made with three different cement types: ordinary Portland cement (OPC), Portland pozzolana cement (PPC), and Portland slag cement (PSC). Specimens were cured in normal water or artificial seawater for periods up to 365 days. The study found that PPC and PSC concretes experienced lower drying shrinkage compared to OPC concrete in both curing conditions. Additionally, blended cement concretes exhibited better workability than OPC concrete. The improved performance of blended cement composites is attributed to the pozzolanic reactions and filler effect of supplementary cementitious materials in PPC and PSC.
Improving the Latency Value by Virtualizing Distributed Data Center and Auto...IOSR Journals
This document discusses improving latency in distributed cloud data centers through virtualization and automation. It begins by explaining the benefits of distributed over centralized data centers, such as lower latency and financial benefits from positioning services close to customers. Virtualizing data centers increases utilization and flexibility. Automation streamlines operations and provisioning. The document proposes using a virtual network with components like switches and virtual LANs to connect virtualized distributed data centers and improve latency. Automating configuration management avoids manual errors and complexity in managing dynamic cloud environments.
This document compares the performance of eco-friendly refrigerants R-507, R-407c, and R404a for retrofitting an R-12 vapor compression refrigeration system. It provides thermodynamic property correlations for these refrigerants and analyzes the coefficient of performance (COP) and compressor volumetric efficiency of a 1-ton refrigeration unit using each refrigerant. The results show the COP and efficiency are nearly the same for R-134a, R-507, R404a and R-407c as for R-12, indicating these refrigerants' suitability for retrofitting existing R-12 systems. In conclusion, retrofitting with these refrigerants is a viable option to phase
IOSR Journal of Pharmacy and Biological Sciences(IOSR-JPBS) is an open access international journal that provides rapid publication (within a month) of articles in all areas of Pharmacy and Biological Science. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Pharmacy and Biological Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Effective Bug Tracking Systems: Theories and ImplementationIOSR Journals
The document discusses effective bug tracking systems and proposes four directions to enhance them:
1. Tool oriented improvements like making setup and installation simpler for open source tools like Bugzilla.
2. Information oriented improvements like ensuring bug reports capture essential details needed to fix issues.
3. Process oriented improvements like simplifying bug reporting and notification processes.
4. User oriented improvements like reducing complexity and improving usability.
The authors developed a prototype bug tracking application to demonstrate how following these directions can help software developers more easily understand and quickly resolve bugs.
This document summarizes a study that used finite element analysis to evaluate vehicle interior safety features. The study analyzed head injury criteria (HIC) from impacts of a free motion headform at various points inside a vehicle model, both with and without interior trim components. Without trim, the HIC exceeded 1000, the safety standard limit, at all impact points. With 2mm thick trim added to the pillars and side rails, the HIC was below 1000 at all points tested. The results indicate that interior trim materials are effective at reducing head accelerations and meeting safety standards during interior impacts.
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2) Two experiments are conducted. The first combines Naive Bayes and Decision List, improving Naive Bayes' accuracy. The second combines AdaBoost and Decision List, further increasing accuracy.
3) A third experiment combines all three approaches, with Decision List as the master. As expected, this achieves the highest accuracy compared to the individual approaches.
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1) The differential equations of continuity, linear momentum, and mass conservation which relate the time rate of change of fluid properties like density and velocity within an infinitesimal control volume.
2) The Navier-Stokes equations which model viscous flow using Newton's laws and relate stresses to strain rates via viscosity.
3) Equations for inviscid, irrotational flow where viscosity and vorticity are neglected.
4) The stream function, a potential function whose contour lines represent streamlines, allowing 2D problems to be solved using a
Numerical Study of Strong Free Surface Flow and Wave BreakingYi Liu
1. The document describes numerical methods for simulating strong free surface flows and wave breaking, including the coupled level set and volume-of-fluid method.
2. Results are presented from simulations of breaking waves under different wind conditions, showing the generation of vortices and effect of wind speed on wave breaking.
3. Future research topics discussed include studying wave breaking mechanisms under different conditions, the interaction of wind turbulence and breaking waves, and multi-scale simulations of wind-wave-structure interaction using immersed boundary methods.
Lattice boltzmann simulation of non newtonian fluid flow in a lid driven cavitIAEME Publication
This document summarizes a study that uses Lattice Boltzmann Method (LBM) to simulate non-Newtonian fluid flow in a lid driven cavity. The study explores the mechanism of non-Newtonian fluid flow using the power law model to represent shear-thinning and shear-thickening fluids. It investigates the influence of power law index and Reynolds number on velocity profiles and streamlines. The LBM code is validated against published results and shows agreement with established theory and fluid rheological behavior.
The document discusses the design of a steel pipeline submerged in moving water. It analyzes the forces on the pipeline from the flowing water, including drag force. Experiments using a wind tunnel were conducted to determine the coefficient of drag on cylindrical objects at different flow velocities. This was then used to calculate the drag force on the 10-inch diameter pipeline placed 200 inches below the surface of water flowing at 10 in/s. The calculated drag force and weight of the pipeline and water above it were then used to design the pipeline to withstand these forces.
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2) Control volume analysis using the linear momentum and angular momentum equations allows determining the forces and torques associated with fluid flow into and out of a control volume.
3) The key forces acting on a control volume are body forces that act throughout the volume, like gravity, and surface forces that act on the control surface, like pressure and viscous forces.
This document summarizes research on modeling the generation of zonal flows (ZFs) in magnetically confined fusion plasmas. A reduced 1D model was developed using an eddy viscosity approach to represent small-scale instabilities as stochastic noise. The model was verified for stationary solutions and stochastic resonance was explored. Future work will involve obtaining temporal solutions and modeling the coupling of ZFs to geodesic acoustic modes. Turbulence in fusion plasmas can be described as 2D, allowing for an inverse energy cascade that promotes the growth of large-scale ZFs.
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2) In turbulent plane Couette flow at low Reynolds numbers, streamwise vortices that span the entire gap between plates have been observed.
3) The document proposes a two-step Galerkin projection method to derive a low-order model that can illustrate the dynamics and generation mechanism of these streamwise vortices, in a way that is analogous to what is observed in turbulent boundary layers.
Literature survey modeling of microfluidics devicesAweshkumarsingh
This presentation discusses modeling of microfluidics devices. It begins with definitions of electrokinetics phenomena like electroosmosis, electrophoresis, and dielectrophoresis that are important in microfluidics. It then discusses various modeling approaches like continuum models using Navier-Stokes equations, molecular dynamics simulations, DSMC, and lattice Boltzmann methods. Examples of applying these methods to study phenomena like mixing and particle separation in microchannels are provided.
This document discusses fluid flow and provides information on several topics:
1) It describes laminar and turbulent flow, and introduces the Reynolds number which determines the transition between these two flow regimes.
2) It discusses mass balances and the continuity equation which states that the rate of mass input equals the rate of mass output in steady state flow.
3) It derives the overall energy balance equation based on the first law of thermodynamics and describes how to apply this to steady state flow systems.
4) It introduces the mechanical energy balance equation which is useful for analyzing flowing liquids and accounts for kinetic energy, potential energy, and frictional losses.
This document discusses fluid mechanics concepts including:
- Identifying vocabulary related to fluid mechanics and energy conservation.
- Explaining physical properties of fluids like density, pressure, and viscosity.
- Recognizing types of fluid flows like laminar, turbulent, compressible, incompressible.
- Understanding concepts like no-slip condition, boundary layers, and streamlines.
- Deriving conservation laws for mass and energy in ideal fluids using Bernoulli's equation.
LATTICE BOLTZMANN SIMULATION OF NON-NEWTONIAN FLUID FLOW IN A LID DRIVEN CAVITY IAEME Publication
Lattice Boltzmann Method (LBM) is used to simulate the lid driven cavity flow to explore the mechanism of non-Newtonian fluid flow. The power law model is used to represent the class of non-Newtonian fluids (shear-thinning and shear-thickening fluids) by considering a range of 0.8 to 1.6. Investigation is carried out to study the influence of power law index and Reynolds number on the variation of velocity profiles and streamlines plots. Velocity profiles and the streamline patterns
for various values of power law index at Reynolds numbers ranging 100 to 3200 are presented. Half way bounce back boundary conditions are employed in the numerical method.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and TechnologyIJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Comparison of flow analysis of a sudden and gradual change of pipe diameter u...eSAT Journals
Abstract This paper describes an analytical approach to describe the areas where Pipes (used for flow of fluids) are mostly susceptible to damage and tries to visualize the flow behaviour in various geometric conditions of a pipe. Fluent software was used to plot the characteristics of the flow and gambit software was used to design the 2D model. Two phase Computational fluid dynamics calculations, using K-epsilon model were employed. This simulation gives the values of pressure and velocity contours at various sections of the pipe in which water as a media. A comparison was made with the sudden and gradual change of pipe diameter (i.e., expansion and contraction of the pipe). The numerical results were validated against experimental data from the literature and were found to be in good agreement. Index Terms: gambit, fluent software.
Apart from TDMA, there are other iterative methods for solving the
system of equations which are faster. Unlike TDMA, which solves
the problem line by line, these iterative methods solves all
equations simultaneously. As a result these methods are faster than
TDMA. Some of the fast iterative methods are
1) SIP (strongly implicit procedure)
2) MSIP (modified SIP)
3) CG (Conjugate gradient method)
4) BiCGSTAB (bi-conjugate gradient stabilized method)
CG method is used for solving linear systems of equations which
have a symmetric coefficient matrix. All other methods mentioned
above are used for systems of equations involving non-symmetric
coefficient matrices.
The document analyzes the effect of surface tension on Kelvin-Helmholtz instability, which occurs at the interface between three immiscible fluid layers. It presents the mathematical formulation of the problem, obtaining a dispersion equation relating wave speed to wavelength. The numerical resolution of this equation shows that longer wavelengths stabilize the flow while shorter wavelengths destabilize it. Surface tension acts to stabilize the interface by suppressing shorter wavelengths.
This document summarizes a study that used computational fluid dynamics (CFD) to analyze vortex induced vibration on an offshore structure through fluid-structure interaction (FSI) modeling. The study performed 2D and 3D CFD analyses to understand flow patterns and validate results. Preliminary one-way FSI analysis was then conducted by coupling structural and fluid solvers to observe the dynamic response of the structure to periodically varying vortex loads. The goal was to better understand vortex induced loads on offshore structures through numerical simulation.
This document contains 74 two-mark questions related to aerodynamics. It covers topics such as the definitions of control volume and surface, steady and unsteady flow, compressible and incompressible flow, continuity equations, potential and stream functions, vortex flows, thin airfoil theory, and more. The questions are short definitions or explanations of aerodynamic concepts.
This document discusses fluid-induced vibration (FIV) in heat exchangers. It covers topics like vortex shedding, synchronization, critical velocity, fluid-elastic instability, and vibration damage patterns. The key points are:
- Vortex shedding from cylindrical structures can cause fluid excitation forces at the shedding frequency, and fluid-structure coupling forces if that frequency matches structural natural frequencies.
- There is a critical cross-flow velocity at which fluid-elastic instability occurs, causing rapid increases in vibration amplitude.
- Vibration damage in heat exchangers can include tube collisions, baffle damage, tube sheet effects, and acoustic resonance failures.
This document describes a numerical study of flow and energy dissipation in stepped spillways using the FLUENT software. Two stepped spillway models with 5 and 10 steps were analyzed for different flow rates. The k-ε turbulence model and volume of fluid method were used to model turbulence and free surface flow. Numerical results for flow patterns, velocities, and energy dissipation were compared to experimental data from other studies, showing good agreement with errors less than 2%. The results indicate that increasing the flow rate or number of steps reduces energy dissipation, while decreasing step height or length also reduces dissipation.
Similar to Modeling of Vortex Induced Vibration based Hydrokinetic Energy Converter (20)
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This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
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This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
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The document summarizes a study of different microstrip patch antenna configurations with slotted ground planes. Three antenna designs were proposed and their performance evaluated through simulation: a conventional square patch, an elliptical patch, and a star-shaped patch. All antennas were mounted on an FR4 substrate. The effects of adding different slot patterns to the ground plane on resonance frequency, bandwidth, gain and efficiency were analyzed parametrically. Key findings were that reshaping the patch and adding slots increased bandwidth and shifted resonance frequency. The elliptical and star patches in particular performed better than the conventional design. Three antenna configurations were selected for fabrication and measurement based on the simulations: a conventional patch with a slot under the patch, an elliptical patch with slots
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2) Drive testing was performed before and after optimization using TEMS software to record network parameters like RxLevel, RxQuality, and events.
3) Analysis found call drops were occurring due to issues like handover failures between sectors, interference from adjacent channels, and overshooting due to antenna tilt.
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This document describes the design of an intelligent autonomous wheeled robot that uses RF transmission for communication. The robot has two modes - automatic mode where it can make its own decisions, and user control mode where a user can control it remotely. It is designed using a microcontroller and can perform tasks like object recognition using computer vision and color detection in MATLAB, as well as wall painting using pneumatic systems. The robot's movement is controlled by DC motors and it uses sensors like ultrasonic sensors and gas sensors to navigate autonomously. RF transmission allows communication between the robot and a remote control unit. The overall aim is to develop a low-cost robotic system for industrial applications like material handling.
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Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
artificial intelligence and data science contents.pptxGauravCar
What is artificial intelligence? Artificial intelligence is the ability of a computer or computer-controlled robot to perform tasks that are commonly associated with the intellectual processes characteristic of humans, such as the ability to reason.
› ...
Artificial intelligence (AI) | Definitio
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Modeling of Vortex Induced Vibration based Hydrokinetic Energy Converter
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 6, Issue 6 (Jul. - Aug. 2013), PP 26-31
www.iosrjournals.org
www.iosrjournals.org 26 | Page
Modeling of Vortex Induced Vibration based Hydrokinetic
Energy Converter
Krishna Manasa Rao1
and Ashray Gururaja Manur2
1, 2
Department of Electrical and Electronics Engineering, Sri Jayachamarajendra College of Engineering, India
Abstract : Vortex Induced Vibrations (VIV) forms the basis of the hydrokinetic energy converter. With the
increasing energy demand, there is a need for a significant shift to using clean and renewable sources of
energy. VIV based hydrokinetic energy converter aims to harness aquatic energy from slow moving water
currents. For modeling, a single cylinder system with single degree-of-freedom is considered. This paper deals
with formulation of generalized equations to characterize the flow oscillator interaction and to develop a model
to carry out experimental observations of the hydrokinetic energy converter. The model will help predict the
dynamic response and ultimately determine the power that can be extracted. The kinetic energy of the fluid flow
produces transverse mechanical motion of the bluff body. This mechanical motion is then used to produce useful
electrical energy with the help of a Power Take Off (PTO) system. The theoretical maximum energy that can be
harnessed by the PTO has also been discussed.
Keywords: Hydrokinetic Energy Converter, Kutta- Joukowski Theorem, Reynolds Number, Strouhal Number,
Vortex Induced Vibrations
I. INTRODUCTION
VIV is a complex fluid-structure phenomenon. Most of the studies in this area have been carried out in
order to minimize the fatigue on the structures caused by VIV. However, recent energy studies related to VIV
has been aimed to enhance the vibrations in order to maximize energy extraction from fluid flow [1]. VIV based
hydrokinetic energy converter has several advantages over conventional hydrokinetic energy converters which
are:
Ability to harness energy from water flow with a flow velocity as low as 0.25 m/s
High energy density
Less likely to cause ecological imbalance
Robust and cost effective
Less maintenance cost
Figure1: Cost comparison of various energy sources [2]
II. NON-LINEARITY IN VIV
Vortex Induced Vibration (VIV) is a highly non-linear phenomenon. When the frequency of vortex
shedding fsis close to the natural frequency of the body in motion𝑓𝑛 , the phenomenon of lock in occurs. The
range of frequencies over which lock in occurs is one of the most important areas of research. Lock in is a non-
linear phenomenon where in, the highest amplitude is not observed exactly at the point where the shedding
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frequency equals the natural frequency. It occurs over a range and is self-limiting in nature where, as the
amplitude of the bluff body increases, the VIV is suppressed which in turn affects the motion of the bluff body.
Figure 2: Basic working principle of VIV based hydrokinetic energy converter
III. MATHEMATICAL MODEL
There are several parameters either in the form of constants or variables which have to be evaluated in
order to model this hydrokinetic energy converter. The natural frequency of the spring-cylinder system is given
by
𝑓𝑛=
1
2П
𝑘
𝑚 𝑎𝑝𝑝
(1)
In the equation above, fnis the natural frequency of the spring-cylinder system, k is the spring constant and
𝑚 𝑎𝑝𝑝 is the apparent mass of the cylinder. Since the cylinder is submerged in the water, its weight cannot be
directly taken for calculation. Its apparent weight as per Archimedes principle has to be considered which is
given as
𝑚 𝑎𝑝𝑝 = 𝑚 𝑜𝑏𝑗 − 𝑚 𝑑𝑖𝑠 (2)
where 𝑚 𝑜𝑏𝑗 is the real weight and𝑚 𝑑𝑖𝑠 is the weight of the fluid displaced.
𝑚 𝑑𝑖𝑠 = 𝜌 𝑓𝑙𝑢𝑖𝑑 ∗ 𝑣𝑜𝑙 𝑐𝑦𝑙 (3)
The natural frequency of the system is important in determining the range in which lock in is likely to occur.
Range over which lock in occurs also depends on mass ratio m* which is defined as
𝑚∗
=
𝑚 𝑑𝑖𝑠
𝑚 𝑜𝑠𝑐
(4)
Figure 3: Reduced Velocity vs. Mass Ratio [3]
U*is a non-dimensional parameter known as reduced velocity. It is used in experimental analysis for measuring
amplitude vibration and is given by
𝑈∗
=
𝑈
𝑓𝑛 𝐷
(5)
For lower values of m*, the upper limit of the lock in begins to grow exponentially, but for lower values the
variation is insignificant.
Reynolds number is one of the most important parameter which describes the structure-fluid interaction. It is
defined as the ratio of inertial forces to viscous forces and is given by
𝑅𝑒 =
𝑈𝑑
𝑣
(6)
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WhereU is the velocity of free stream, d is the characteristic length and v is the kinematic viscosity.
Figure 4: Regimes of fluid flow across cylinders [4]
For effective working of the hydrokinetic energy converter in discussion, dead zones should be avoided as the
net lift force generated due to VIV is negligent or nil. In lower regimes, the fluid flow is laminar which is not
useful for energy generation. As the Reynolds number is increased, a laminar to turbulent transition takes place
in the vortices. In the range of 105
<Re< 5*105
, the laminar boundary on the cylinder becomes turbulent. Another
important non-dimensional parameter used to describe oscillating flow conditions is Strouhal number. It relates
the frequency of vortex shedding to the flow conditions and is given by
𝑆 =
𝑓𝑠 𝐷
𝑈
(7)
where 𝑓𝑠 is the frequency of vortex shedding, D is the diameter of the cylinder and U is the fluid flow velocity.
For large Strouhal numbers, viscosity dominates fluid flow, resulting in a collective oscillating movement of the
fluid. For low Strouhal numbers (order of 10-4
and below) the high-speed quasi steady-state portion of the
movement dominates the oscillation. Oscillations at intermediate Strouhal numbers are characterized by build-
up and rapidly subsequent shedding vortices. The vortex shedding frequency is evaluated from the above
equation on the rough assumption that Strouhal number has a constant value of 0.21 [4]. The lift force is another
important parameter which plays a vital role in determining the final energy output. The Kutta–
Joukowskitheorem can be used to determine the quantity of lift on the bluff body due to fluid flow. It is given by
𝑚𝑦 + 𝑐𝑦 + 𝑘𝑦 = 𝐿 (8)
𝐿 = 𝜌𝑈𝛤 (9)
ρ is the density of fluid, U is the velocity of the fluid andΓis defined as
Γ = 𝑈 ∙ 𝑑𝑠 (10)
The line integral is around a contour in anti-clockwise direction enclosing the cylinder such that the path is in
the region of potential flow and not in the boundary layer of the cylinder. Linear equations for amplitude of
oscillation and lift coefficient can be written as
𝑦 = 𝑦 𝑚𝑎𝑥 sin(2П𝑓𝑠 𝑡) (11)
𝑐 𝐿 𝑡 = 𝐶𝐿sin(2π𝑓𝑠 𝑡 + 𝜑) (12)
In the above two equations, ymax is the maximum amplitude of oscillation, 𝜑 is the phase angle between fluid
force and displacement, 𝑐 𝐿 is time independent lift coefficient and CL is the amplitude of lift coefficient of the
cylinder.The power in the fluid which is flowing over the cylinder whose motion is perpendicular to the fluid
flow is given by
𝑃𝑜𝑤𝑒𝑟𝑖𝑛𝑓𝑙𝑢𝑖𝑑 =
1
2
𝜌𝑈2
∗ 𝐷𝐿 (13)
Here ρ is the density of the fluid, D is the diameter of the cylinder, U is the stream velocity and L is the length of
the cylinder.The work done by the fluid acting on the bluff body during a vortex induced vibration cycle is
given by
𝑊𝑉𝐼𝑉 = 𝐹𝑓𝑙𝑢 𝑖𝑑
𝑇 𝑐𝑦𝑙
0
𝑦 𝑑𝑡 (14)
The fluid power due to VIV is
𝑃𝑉𝐼𝑉 =
𝑊 𝑉𝐼𝑉
𝑇 𝑐𝑦𝑙
(15)
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To obtain 𝑃𝑉𝐼𝑉 , we multiply the force from (8) with the instantaneous velocity and perform the integration as
above to obtain
𝑃𝑉𝐼𝑉 =
1
2
𝜌𝐶𝐿 𝑓𝑠 𝑦 𝑚𝑎𝑥 𝐷𝐿𝑠𝑖𝑛(𝜑) (16)
The efficiency of the system can then be given as
𝜂 𝑉𝐼𝑉 =
𝑃 𝑉𝐼𝑉
𝑃𝑜𝑤𝑒𝑟𝑖𝑛𝑡 𝑒𝑓𝑙𝑢𝑖𝑑
(17)
From (13) and (16) we have
𝜂 𝑉𝐼𝑉 =
1
2
𝜌 𝐶 𝐿 𝑓𝑠 𝑦 𝑚𝑎𝑥 𝐷𝐿𝑠𝑖𝑛 (𝜑)
1
2
𝜌 𝑈2∗𝐷𝐿
(18)
IV. MODELING OF PHYSICAL FEATURES OF FLUID FLOW
There are several physical features which directly affect the mathematical model.
Stagnation point
Separation point
Formation point
Boundary layer
Shear layer
The stagnation point 𝜃𝑠𝑡 is the point of zero velocity on the body. In viscous flow, it is defined as the point of
highest pressure. The stagnation point moves with the motion of the body as well as the formation and shedding
of the vortices. The amplitude of motion of the stagnation point is denoted by Θ 𝑠𝑡 and the relation between the
stagnation point and amplitude of motion of stagnation point is given by
𝜃𝑠𝑡 = Θ 𝑠𝑡 𝑓(𝑡) (19)
The separation point is defined as the point where the wall shear stress is exactly zero or the point where fluid
particles leave the wall. A strong relationship between separation point and Reynolds number has been
established.
𝜃𝑠𝑝 = Θ 𝑠𝑝 𝑓(𝑡) (20)
Formation point is a point in the near wake at which the shear layer saturates and begins to form the
𝑣𝑜𝑛𝐾𝑎 𝑟𝑚𝑎 𝑛 vortex. It moves away from the body during the formation of the vortex and quickly snaps back to
the body during the shedding of the vortex. Denoted byxfp, it is highly dependent on Re and experiments have
been carried out to prove the dependence of formation point on the Reynolds number [5].The boundary layer
exists between the stagnation point and each respective separation point. It is highly dependent on Re since
viscous forces dominate in this region. The shear layer exists between the separation point and the formation
point. The shear layer is also known as the feeding layer in the case of VIV since it feeds energy into the vortex.
V. MODELING OF DYNAMIC RESPONSE OF BLUFF BODY
Dynamic response of a bluff body in fluid flow incorporates finding the amplitude of vibration of the
cylinder. This has been one of the most crucial tasks of mathematical modeling. In the hydrokinetic energy
converter, the bluff body is supported by a spring system which aids its movement. The amplitude of vibration
can be found out practically. However, arriving at a range of values for the amplitude is theoretically
complicated and often not very effective because several factors such as losses in vibration owing to spring
action and viscosity are not taken into consideration. When a cylindrical bluff body is moving in water, the
amplitude envelope is described by a decaying exponential function which is given by
𝑦 = 𝑎𝑒 𝜎𝑥
(21)
wherea is the amplitude factor and 𝜎 is the product of damping coefficient χ and ωn, which is the natural
frequency of the system while x is the vortex shedding frequency. The above equation is a Gaussian equation for
finding the amplitude of a system immersed in water. Envelopes are used to control the way vortices change
over time. The amplitude envelope of a vortex, when a cylindrical bluff body is used can be given by
𝑦 = cos 2𝑥 𝑒−0.05𝑥
(22)
where x is the vortex shedding frequency.
ln 𝑦 = ln 𝑎 + 𝜎𝑥 (23)
In order to calculate the values of a and 𝜎 we optimize the following
𝑌 = 𝐴 + 𝐵𝑋 (24)
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Using piece-wise linear minimization we obtain
𝐴 =
1 𝑥1
⋮ ⋮
1 𝑥𝑛
𝐵 =
𝑏1
⋮
𝑏𝑛
𝑝 =
𝑎
⋮
𝜎
wherep is the optimized solution. The amplitude is then calculated using the formula
𝑎𝑚𝑝𝑙𝑖𝑡𝑢𝑑𝑒 = 𝑝𝑒 𝜎𝑥
(25)
For simulating the working of VIV based hydrokinetic energy converter, it is essential to create artificial river
flow conditions. This requires large channels of flowing water involving multi-layer fluid flow. To make the
experimental setup cost-effective, a recirculating tank was manufactured. Recirculating flow was established
with the help of central channel and flow guide vanes. In the absence of recirculating fluid flow, the dynamic
response of the bluff body obtained in MATLAB is shown in fig 5.
Figure 5: Dynamic Response of bluff body in fluid flow
VI. ELECTRIC POWER OUTPUT OF PTO
The PTO of the hydrokinetic energy converter is a linear generator [6]. It is primarily based on
Faraday’s laws of electromagnetic induction.
𝐸 = 𝑁
𝑑𝜙
𝑑𝑡
(26)
𝜙 𝐵 = 𝐵𝐴(𝑐𝑜𝑠𝜃) (27)
Bis the magnetic field strength,A is the area and 𝜃 is the angle between B and normal to the area A. The two
factors A and B depend on the magnet design and coil optimization. The EMF produced will depend on number
of turns of wire and rate of change of flux. The rate of change of flux depends on the motion of the bluff body.
Although the speed of the cylinder changes continuously, in order to simplify the calculations, the average speed
of the cylinder which is equal to v was taken. The rate of change of flux is now given by
𝑑𝜙 𝐵
𝑑𝑡
=
𝜙 𝐵
𝑣
(28)
wherehis the height of the winding. The core-coil system in the linear generator employs single magnet and
multiple-coil assembly. The number of turns on the iron core is given by
𝑁 =
𝑟𝑐 −𝑎
𝑔
∗
𝑤 𝑛
𝑔
(29)
rcis the core diameter including the windings, wn is the width of the notch and g is the gauge of the wire. The
calculation for the length of the copper wire that should be obtained for N number of turns is fairly complicated.
This is because even though the length of one turn is equal to the circumference of that layer, each subsequent
layer will increase the radius of the core with the coil.
𝑙𝑒𝑛𝑔𝑡𝑜𝑓𝑐𝑜𝑝𝑝𝑒𝑟𝑤𝑖𝑟𝑒 𝑙𝑛𝑒𝑒𝑑𝑒𝑑 =
𝑤 𝑛
𝑔
∗ 2Π
𝑛=
𝑟 𝑐−𝑎
𝑔
𝑛=0 ∗ (𝑎 + 𝑛𝑔) (30)
The length of the copper wire directly affects the inductance of the system and the inductance of a coil with an
air core is given by
𝐿0 =
𝑁2 𝑟
6𝑟+9𝑙+10𝑑
(31)
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N is the number of turns, l is the length of the wire, d is the thickness and r is the radius of the copper wire.
However, an iron core is used in the linear generator and the inductance of an iron core system is given by
𝐿 = 𝐿0 ∗
𝜇
𝜇0
(32)
𝜇 is the permeability of the core and 𝜇0 is the permeability of air. High inductance increases the time constant of
the electrical system. It is given by
𝜏 =
𝐿
𝑅
(33)
For a generator to produce electrical power output it must contain a closed circuit. The coil system of the linear
generator itself is not a closed circuit. The linear generator system essentially is a RL circuit and its output is
𝐼 =
𝑉
𝑅
∗ (1 − 𝑒−
𝑡
𝜏 ) (34)
𝑃 𝑡 = 𝑉𝐼 (35)
VII. SIMULATION RESULTS
Table 1: Simulation results obtained in MATLAB
Diameter of
cylinder (in m)
Length of the
cylinder (in m)
N (number of
cylinders)
U (velocity of
stream)
Output Power of
PTO (MW)
0.5 1 20 0.25 0.0767
0.5 1 20 0.4 0.1552
0.5 1 50 0.3 0.4019
0.5 1 50 0.45 0.663
0.5 1 500 0.75 0.9498
0.5 5 20 0.5 1.2537
0.5 5 50 0.66 1.6931
1 5 50 0.5 2.0505
2 5 200 0.3 8.1197
2 5 500 0.5 9.6421
2 10 200 0.3 37.0376
2 10 900 0.75 88.1188
VIII. CONCLUSION
In this paper, a new mathematical model has been developed taking into consideration all parameters that are
physically meaningful and experimentally measurable. The model involves non-linearity and acylinder system
with single degree-of-freedom. A detailed analysis of the dynamic response has been presented, keeping in mind
energy extraction as paramount importance. It is extremely important to harness the energy available due to VIV
and hence modeling of PTO plays an important role in the overall energy extraction. The simulation results
illustrate that VIV based hydrokinetic energy converter has great potency in the field of green renewable energy.
IX. ACKNOWLEDGEMENTS
The authors would like to thank Mrs. G M Rekha and Mrs.Kamalini R for funding this project and for their
constant enthusiasm and encouragement. Special thanks to Ms.Anusha Gururaja Manur and Ms.Manisha
Krishna Rao who have been a pillar of support and without whose help this project could not have been
successfully completed.
REFERENCES
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converter,”Technical report, The University of Michigan Graham Environmental Sustainability Institute, 2006
[2] M. M. Bernitsas, K. Raghavan, Y. Ben-Simon, and E. M. H. Garcia, “VIVACE (Vortex Induced Vibration for Aquatic Clean
Energy): A new concept in generation of clean and renewable energy from fluid flow,”Journal of Offshore Mechanics andArctic
Engineering, vol. 130,2008
[3] C.H.K.Williamson and R. Govardhan, “Vortex-Induced Vibrations,” Annual Review of Fluid Mechanics, vol. 36, pp. 413-455,
January 2004.
[4] John H. Leinhard, Synopsis of Lift, Drag, and Vortex Frequency data for Rigid Cylinders ,Washington State University, 1966
[5] A. Prasad and C. H. K. Williamson, “The instability of the shear layer separation from a bluff body,”Journal of Fluid Mechanics
333, 375-402, 1997
[6] Krishna Manasa Rao and Ashray Gururaja Manur, “Design Optimization of Linear Generator for a Hydrokinetic Energy
Converter,” IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE), Volume 6, Issue 1, PP 37-40, 2013