International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
EXPERIMENTAL STUDY ON SOLAR HEATING BY NATURAL HEAT CONVECTION AND RADIATIONADEIJ Journal
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Heat storage is a good energy saving option these days. Heat storage makes it possible to use thermal
energy at the required time. Solar water heaters for construction purposes and industrial purposes are the
best source to maintain traditional energy sources and thus can maintain high quality energy and liquid or
steel fuel due to the highest rise in their prices. In recent years, using solar energy has become remarkably
cheap and especially noteworthy. The efficiency of natural solar water heater system depends on collector
and reservoir setting, design and environmental factors such as solar intensity, ambient temperature and
wind conditions. Also, the relative height of the tank and collector separation mainly affects the volume of
the Siphon thermal flow rates, including both forward and reverse flow at night. In this pilot investigation,
two parallel rectangular glass plates were connected to the hot water storage tank. The effect of the
separation space between the plates (collectors) (D) was investigated and reported. The results reported
that outlet temperature in case D= 15 cm for two plates decreased approximately 24% and 23% for two
plates. Also, the heat radiated to the room decreased as the inner space between the two plates increased,
and decreased to approximately 25% as compared to stack plates.
In this communication, an attempt has been made to find out the heat transfer coefficients such as internal and external heat transfer modes and thermophysical properties such as dynamic viscosity, density, thermal conductivity, latent heat of evaporation and saturated vapor pressure for active solar distillation system. It is observed that water temperature plays a vital role in the distillate output (the yield) since it increases significantly with the rise of basin water temperature. Double slope step type solar still of area 1 m2 is constructed using a glass pieces. Top Glass cover with 10° slope ensures a very good transmission of solar radiation inside the still. The distillate water productivity is in the range of 2.758 litres to 2.805 liters per day for still performance study. Similarly the instantaneous efficiency for still performance study is in the range of 17.84% to18.25%. Dimensionless numbers such as the Nusselt number (Nu), the Grashof number (Gr), the Reynolds number (Re) and the Prandtl number (Pr) were also estimated. Heat transfer coefficient were estimated for the present system since the system overall efficiency depend on heat transfer modes. Internal (convection, evaporation and radiation) and external (convection, conduction and radiation) heat transfer modes were calculated for the present system and it is found that because of rise in water temperature, evaporative heat transfer coefficient value rises significantly.
EXPERIMENTAL STUDY ON SOLAR HEATING BY NATURAL HEAT CONVECTION AND RADIATIONADEIJ Journal
Â
Heat storage is a good energy saving option these days. Heat storage makes it possible to use thermal
energy at the required time. Solar water heaters for construction purposes and industrial purposes are the
best source to maintain traditional energy sources and thus can maintain high quality energy and liquid or
steel fuel due to the highest rise in their prices. In recent years, using solar energy has become remarkably
cheap and especially noteworthy. The efficiency of natural solar water heater system depends on collector
and reservoir setting, design and environmental factors such as solar intensity, ambient temperature and
wind conditions. Also, the relative height of the tank and collector separation mainly affects the volume of
the Siphon thermal flow rates, including both forward and reverse flow at night. In this pilot investigation,
two parallel rectangular glass plates were connected to the hot water storage tank. The effect of the
separation space between the plates (collectors) (D) was investigated and reported. The results reported
that outlet temperature in case D= 15 cm for two plates decreased approximately 24% and 23% for two
plates. Also, the heat radiated to the room decreased as the inner space between the two plates increased,
and decreased to approximately 25% as compared to stack plates.
In this communication, an attempt has been made to find out the heat transfer coefficients such as internal and external heat transfer modes and thermophysical properties such as dynamic viscosity, density, thermal conductivity, latent heat of evaporation and saturated vapor pressure for active solar distillation system. It is observed that water temperature plays a vital role in the distillate output (the yield) since it increases significantly with the rise of basin water temperature. Double slope step type solar still of area 1 m2 is constructed using a glass pieces. Top Glass cover with 10° slope ensures a very good transmission of solar radiation inside the still. The distillate water productivity is in the range of 2.758 litres to 2.805 liters per day for still performance study. Similarly the instantaneous efficiency for still performance study is in the range of 17.84% to18.25%. Dimensionless numbers such as the Nusselt number (Nu), the Grashof number (Gr), the Reynolds number (Re) and the Prandtl number (Pr) were also estimated. Heat transfer coefficient were estimated for the present system since the system overall efficiency depend on heat transfer modes. Internal (convection, evaporation and radiation) and external (convection, conduction and radiation) heat transfer modes were calculated for the present system and it is found that because of rise in water temperature, evaporative heat transfer coefficient value rises significantly.
Theoretical study of heat transfer through a sun space filled with a porous m...Ahmed Al-Sammarraie
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A theoretical study had been conducted to detect the effect of using a porous medium in sunspace to reduce heating load and overcoming coldness of winter in the cold regions. In this work, the heat transferred and stored in the storage wall was investigated. The mathematical model was unsteady, heat conduction equation with nonlinear boundary conditions was solved by using finite difference method and the solution technique of heat conduction had based on the Crank Nicholson method. The results had adopted on the aspect ratio (H/L=30), Darcy number (Da=10-3), porosity (Ď=0.35) and particle to fluid thermal conductivity ratio (kp/kf=38.5). The results showed that using the porous medium had enhanced the heat transferred and stored in the storage wall. For the outside storage wall temperature, an increase of 19.7% was achieved by using the porous medium instead of the air, while it was 20.3% for the inside storage wall temperature.
From our climate panel in Grand Junction on August 4:
Our Forest, Our Water, Our Land: Local Impacts on Climate Change. Sponsored by Conservation Colorado, Mesa County Library, Math & Science Center
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...IAEME Publication
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In the present work, the enhancement of natural convection heat transfer utilizing nano fluids as working fluid from horizontal circular cylinder situated in a square enclosure is investigated numerically. Different types of nano particles were tested. The types of the nano fluids are Cu, Al2O3 and TiO3 with water as base fluid. A model is developed to analyze heat transfer performance of nano fluids inside an enclosure taking into account the solid particle dispersionrs on the flow and heat
transfer characteristics.
KonzervatĂvny inĹĄtitĂşt M. R. Ĺ tefĂĄnika v spoluprĂĄci s partnermi organizoval ÄalĹĄiu z cyklu prednĂĄĹĄok CEQLS. DĹa 20. jĂşna 2016 v Bratislave prednĂĄĹĄal Patrick Michaels, riaditeÄž Centra pre vedeckĂ˝ vĂ˝skum v Cato Institute (USA). Viac informĂĄciĂ na www.konzervativizmus.sk
Fuzzy numbers, Nth - order Fuzzy Initial Value Problems, Runge-Kutta method, ...IOSR Journals
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A numerical study is presented of two-dimensional laminar steady-state on megneto-hydrodynamics
(MHD) free convection for heat flow patterns within trapezoidal enclosures. A finite element analysis is
performed to investigate the effects of unifor heating and is also used for solving the Navier-Stokes and
Energybalance equations.In this study, cold bottom walls, uniformly heated left and right (side) walls and
insulated top walls with inclination angles (Ń) are considered in a trapezoidal enclosure. The present numerical
procedure adopted in this investigation yields consistent performance over a wide range of parameters, Prandtl
numbers, (Pr = 0.026 - 0.7), and Rayleigh numbers (Ra = 103 â 105), Hartmann number (Ha = 50) with various
tilt angles Ф = 450, 300 and 00(square).Numerical results are presented in terms of streamlines, isotherms, heat
function (total heat flux) and nusselt numbers.for different Ra and Pr. As Ra increases conduction dominant
region changes for different Pr. Complete heat transfer analysis is performed in terms of local and average
nusselt numbers.
Tours de viaje con precio especial a partir de 2 personas. 2013 MapaplusMapaplus
Â
Programas para viajar a Europa con precio de oferta para un mĂnimo de 2 personas viajando juntas. Tours con duraciĂłn desde 15 hasta 34 dĂas de viaje. Salidas desde AmĂŠrica con vuelo intercontinental en 2013 y abril de 2014.
Theoretical study of heat transfer through a sun space filled with a porous m...Ahmed Al-Sammarraie
Â
A theoretical study had been conducted to detect the effect of using a porous medium in sunspace to reduce heating load and overcoming coldness of winter in the cold regions. In this work, the heat transferred and stored in the storage wall was investigated. The mathematical model was unsteady, heat conduction equation with nonlinear boundary conditions was solved by using finite difference method and the solution technique of heat conduction had based on the Crank Nicholson method. The results had adopted on the aspect ratio (H/L=30), Darcy number (Da=10-3), porosity (Ď=0.35) and particle to fluid thermal conductivity ratio (kp/kf=38.5). The results showed that using the porous medium had enhanced the heat transferred and stored in the storage wall. For the outside storage wall temperature, an increase of 19.7% was achieved by using the porous medium instead of the air, while it was 20.3% for the inside storage wall temperature.
From our climate panel in Grand Junction on August 4:
Our Forest, Our Water, Our Land: Local Impacts on Climate Change. Sponsored by Conservation Colorado, Mesa County Library, Math & Science Center
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...IAEME Publication
Â
In the present work, the enhancement of natural convection heat transfer utilizing nano fluids as working fluid from horizontal circular cylinder situated in a square enclosure is investigated numerically. Different types of nano particles were tested. The types of the nano fluids are Cu, Al2O3 and TiO3 with water as base fluid. A model is developed to analyze heat transfer performance of nano fluids inside an enclosure taking into account the solid particle dispersionrs on the flow and heat
transfer characteristics.
KonzervatĂvny inĹĄtitĂşt M. R. Ĺ tefĂĄnika v spoluprĂĄci s partnermi organizoval ÄalĹĄiu z cyklu prednĂĄĹĄok CEQLS. DĹa 20. jĂşna 2016 v Bratislave prednĂĄĹĄal Patrick Michaels, riaditeÄž Centra pre vedeckĂ˝ vĂ˝skum v Cato Institute (USA). Viac informĂĄciĂ na www.konzervativizmus.sk
Fuzzy numbers, Nth - order Fuzzy Initial Value Problems, Runge-Kutta method, ...IOSR Journals
Â
A numerical study is presented of two-dimensional laminar steady-state on megneto-hydrodynamics
(MHD) free convection for heat flow patterns within trapezoidal enclosures. A finite element analysis is
performed to investigate the effects of unifor heating and is also used for solving the Navier-Stokes and
Energybalance equations.In this study, cold bottom walls, uniformly heated left and right (side) walls and
insulated top walls with inclination angles (Ń) are considered in a trapezoidal enclosure. The present numerical
procedure adopted in this investigation yields consistent performance over a wide range of parameters, Prandtl
numbers, (Pr = 0.026 - 0.7), and Rayleigh numbers (Ra = 103 â 105), Hartmann number (Ha = 50) with various
tilt angles Ф = 450, 300 and 00(square).Numerical results are presented in terms of streamlines, isotherms, heat
function (total heat flux) and nusselt numbers.for different Ra and Pr. As Ra increases conduction dominant
region changes for different Pr. Complete heat transfer analysis is performed in terms of local and average
nusselt numbers.
Tours de viaje con precio especial a partir de 2 personas. 2013 MapaplusMapaplus
Â
Programas para viajar a Europa con precio de oferta para un mĂnimo de 2 personas viajando juntas. Tours con duraciĂłn desde 15 hasta 34 dĂas de viaje. Salidas desde AmĂŠrica con vuelo intercontinental en 2013 y abril de 2014.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
As companies examine their total cost of operations, energy usage and heat recovery deliver cost savings through increased energy utilization and efficiency. Heat exchangers offer companies the opportunity to reuse energy generated for a specific purpose instead of venting that energy to the atmosphere. Shell and tube heat exchangers are in wide use throughout the Food, Dairy, Beverage, Pharmaceutical, Chemicals, Petroleum Refining, and Utility industries. This paper briefly explores three modes of heat transfer and basic designs found in shell and tube heat exchangers. Also included are several case studies from different industries where
EnerquipÂâs heat exchangers have saved the operators energy and money.
A three-dimensional numerical analysis of laminar natural convection with entropy generation in an open trapezoidal cavity filled with water has been carried out. In this investigation, the inclined wall is maintained at isothermal hot temperature while cold water enters into the cavity from its right open boundary and all other walls are assumed to be perfect thermal insulators. Attention is paid on the effects of buoyancy forces on the flow structure and temperature distribution inside the open enclosure. Rayleigh number is the main parameter which changes from 103 to 105 and Prandtl number is fixed at Pr =6.2. Obtained results have been presented in the form of particles trajectories, iso-surfaces of temperature and those of entropy generated as well as the average Nusselt number. It has been found that the flow structure is sensitive to the value of Rayleigh number and that heat transfer increases with increasing this parameter.
Study on Natural Convection in a Square Cavity with Wavy right vertical wall ...IOSRJMCE
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In the present study, natural convection problem has been solved in a cavity having three flat walls and the right vertical wall consisting of one undulation and three undulations. The two vertical and bottom walls are cold walls maintained at a fixed temperature whereas the top wall is heated with spatially varying temperature distribution. Air has been taken as the working fluid with Pr =0.71. This problem is solved by SIMPLE algorithm with deferred QUICK scheme in curvilinear co-ordinates. A wide range of Rayleigh number (103 to 106 ) has been chosen for this study. For small Ra, the heat transfer was dominated by conduction across the fluid layers. With increase of Ra, the process began to be dominated by convection. In the presence of undulation the peak point of the heat rejection (negative local Nusselt number) in the right wall increases by 5.54% than left wall for Ra = 104 . The three undulations case had maximum heat transfer to the uppermost undulation compared to that of the one undulation case
The Effects of Nanofluids on Forced Convection Heat Transfer Inside Parallel ...AI Publications
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A numerical solution on forced convection of Al2O3-water nanofluid for different volume fractions is investigated for laminar flow through a parallel plate with flush mounted discrete heat sources. The model used for nanofluid mixture is a single-phase approach and fluid properties are considered constant with temperature. The finite difference method is used for solutions and four different volume fractions are considered varying from 0% to 4%. A fully developed laminar velocity profile is considered and the parallel plate is assumed as heated with three discrete heat sources flush mounted to the top and bottom plate with the same lengths. Uniform wall temperature boundary condition is taken for discrete heaters. Peclet numbers are in the range of 20-100. For comparison and validity of the solution the results for a classical problem, laminar flow through a parallel plate which is heated at the downstream region with constant temperature, are obtained. Results are presented in terms of bulk temperature, heat flux, and local Nusselt number. Heat transfer is enhanced with the particle volume concentration. For comparison, pure water results are also shown in the figures. At the locations where heat is applied the heat flux values decrease as the volume fraction increase and the bulk temperature values are higher for the higher volume fractions at the heated locations. As the volume fraction increases the local Nusselt number can increase up to 30% than to pure water.
The International Journal of Engineering and Science (The IJES)theijes
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The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Effect of Thermo-Diffusion and Chemical Reaction on Mixed Convective Heat And...IJERA Editor
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A finite element study of combined heat and mass transfer flow through a porous medium in a circular cylindrical annulus with Soret and Dufour effects in the presence of heat sources has been analyzed. The coupled velocity, energy, and diffusion equations are solved numerically by using Galerkin- finite element technique. Shear stress, Nusslet number and Sherwood number are evaluated numerically for different values of the governing parameters under consideration and are shown in tabular form.
Research Inventy : International Journal of Engineering and Scienceinventy
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Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Visualization of Natural Convection in a Vertical Annular Cylinder with a Par...IJERA Editor
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In this work, we visualize the effect of varying wall temperature on the heat transfer by supplying the heat at
three different positions to the vertical annular cylinder embedded with porous medium. Finite element method
has been used to solve the governing equations. Influence of Aspect ratio đ´đ , Radius ratio đ đ on Nusselt
number đ đ˘ is presented. The effect of power law exponent effect for different values of Rayleigh number is
discussed. The fluid flow and heat transfer is presented in terms of streamlines and isotherms.
Abstract:
Introduction: The several ways that thermal energy is transferred from one place to another are referred to as the principle of heat transfer.
This process is known as radiation heat transfer.
The transfer of energy by thermal radiation, or electromagnetic waves, is known as radiant heat transfer.
A convection current is created when heated air rises and is replaced by colder air, transferring heat from the inner pane to the outside pane(s).
Heat is carried via the window frame in triple-glazing units; convection is minor in double-glazing units up to 20 mm, especially when argon gas is used, which is denser than air.
Heat transfer through buildings rooms and roofs: Even while convection often involves more variables than conduction, we are nevertheless able to characterize it and do some simple, accurate calculations to determine its effects.
Figure 7 illustrates each of the three heat transmission techniques in this portion of the attic.
This natural convection heating system, when correctly built, may be quite effective in heating a home evenly.
Environmental Heat Transfer
4
Introduction:
The several ways that thermal energy is transferred from one place to another are referred to as the principle of heat transfer. There are three main ways that heat travels through building assemblies: radiation, convection, and conduction. One or more of these mechanisms may be involved in a specific thermal energy transfer. Phase transitions also release or absorb heat through three processes: conduction, radiation, and convection. Examples of this include heat transfer from walls to rooms, from fluids to each other, between pipes, and from outside heat to dwellings. The types of heat transport are described in Figure 1. a (concept group LLC, 2023)
Figure 1: types of transferring heat. (energy saver, 2023)
Temperature and heat are not the same thing. Temperature is a measurement of the intensity of kinetic energy, which is what heat is. Consider two water containers, one holding 10 gallons and the other one holding 1 gallon, to demonstrate this. Both containers hold 50°F water. The bigger container retains ten times more heat than the smaller one, even if they are of the same temperature. Because it has a greater capacity, the larger container can hold more heat. (Clayton DeKorne, 2023)
Building heat transfer calculations are performed for different applications such as: (Kusuda T., 1977)
⢠heat transmission via the outer envelope, the basement walls, the slab-on-grade floor (to a semi-infinite zone),
⢠transmission, absorption, and reflection of short wavelengths (or solar heat) for openings.
⢠thermal storage in the external masses of structures.
Environmental Heat Transfer
5
⢠air leakage via outside envelopes as well as the interior partition walls, ceilings, and floors.
Interior environmental analyses-:
⢠radiant heat transfer between heat sinks or sources and interior surfaces,
⢠the transfer of heat convectively between interior surfaces an
Cooling Of Power Converters by Natural ConvectionIJERA Editor
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This paper discusses the numerical analysis of the effect of a discontinuous heat flux on heat transfer by natural convection along a vertical flat plate or in a rectangular channel. The objective of this study is to determine the effect of a discrete distribution of the heat flux on the cooling of twelve resistors, which represent electronic components, that are mounted on an aluminium vertical plate. The results of the simulations show that the distribution of the heat flux significantly influences the heat transfer.
Effect of Radiation on Mixed Convection Flow of a Non-Newtonian Nan fluid ove...IJMER
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International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Summary: It is not disputed that mean temperature of Earth has increased by 0.8° C since the early 20th century. Various factors affecting Earthâs surface temperature have been examined and it is found that no mathematical correlation exists between those factors and Global Warming. It is suggested that Earth dynamically keeps its surface temperature.
An introductory outline of the Physics of Heat. I created this presentation at Curtin Sarawak Malaysia as a basis for Foundation Physics students and others to edit and expand. Except where otherwise noted, this work is licensed under the Creative Commons Attribution-Share Alike 2.5 Malaysia License.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
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Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
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Are you looking to streamline your workflows and boost your projectsâ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, youâre in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part âEssentials of Automationâ series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Hereâs what youâll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
Weâll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Donât miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
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Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
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91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
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Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overviewâ
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
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Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But thereâs more:
In a second workflow supporting the same use case, youâll see:
Your campaign sent to target colleagues for approval
If the âApproveâ button is clicked, a Jira/Zendesk ticket is created for the marketing design team
Butâif the âRejectâ button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
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G0372036039
1. International Journal of Engineering Science Invention
ISSN (Online): 2319 â 6734, ISSN (Print): 2319 â 6726
www.ijesi.org Volume 3 Issue 7 Ç July2014 Ç PP.36-39
www.ijesi.org 36 | Page
The Occurrence Of Successive Temperature Inversions In A Non-
Convective Pool Subjectedto Multiple Absorbing Layers
1
Kamgba, F.A., 2
Ekpe,E.O., 3
Nnawuchi,M.N
1Cross River University of Technology, Calabar Nigeria
2 Ebonyi State University, Abakaliki Nigeria.
ABSTRACT : A survey on âThe occurrence of successive temperature inversions in a non-convective pool
subjected to multiple absorbing layersâ was conducted in Cross River University of Technology, Calabar.
Temperature gradient data were generated by monitoring temperature variation with height for four
experimental model pools D1,D2,D3 and D0 with one ,two, three and zero absorbing layers(transparent glass
material of thickness 0.5cm) respectively, using high accuracy mercury in-glass thermometers. The model pools
were drums of height 80cm, perforated at graduated distances where thermometers were inserted and lagged
with insulating materials(Styropor) of thickness 25cm. The multiple absorbing layers were placed at the top of
the drums at interval distances of 10cm between them. Temperature monitoring was carried out between 6am
and 6pm daily for three months in two seasons (dry and wet season) on hourly basis. Results obtained from this
study showed that multiple positive and negative inversion temperature points were observed across the three
non-convective pools with pool D1 having it at 45.0cm, pool D2 at 35.0cm and pool D 3 at 22.0cm.This, The
inversion temperature ranged between 1O
C to 10O
C and occurring at all times of the day with convex (negative)
inversion being more prominent.
I. GENERAL INTRODUCTION
The world over, the necessity for the development of an alternative energy source is borne out of the
fact that fossil fuels are increasingly becoming higher in cost and causing global environmental problems.
Energy required for heating and cooling of buildings is approximately 30% of the total world energy
consumption. Natural ventilation and renewable energy utilization are widely used to improve the indoor air
environment and reduce the energy consumption of air conditioning (Wang and Anguli, 2006). Renewable
energy utilization has a direct link with passive solar architecture. The development and use of passive solar
energy architecture also has its attendant effects.The behaviour of any passive solar energy collector system is
attributed to its temperature gradient )(
dx
dT
(Barnard and Sctterwall, 2003). The gradient provides for free
energy transfer from one point of the collector to another by a simple free convectional process. During this
process, the solar energy reaching a particular region on the earth is being trapped. The trapping of energy
leads to temperature increase based on energy transformation or decrease depending on the direction of the
energy flow (Carring, 1968). ). However, solar energy reaching any collector system exhibits regular cyclic
characteristics defined by the Earth-Sun geometry. This is due purely to superimposed irregularities caused by
the atmospheric conditions (Engel and Reld, 2006): ). In almost all the passive solar applications, the time
pattern of energy demand is not the same as the time pattern of energy reception .This is consequent upon the
fact that some forms of energy stored is needed for use when the collector energy cannot meet the demand
(wang et al.2006). In most collector systems like the non-convective pool (solar pond), convective solar pond
and the atmospheric layer, the behaviour of energy transfer is the same. It is observed that the energy transfer in
these media is transient. This is due to the temperature profile within these systems which has a linear
relationship with the source producing it (Kooi, 1979).
During the process of energy transfer, there is an area within which the temperature either increases or
decreases sharply. This phenomenon is called temperature inversion. The inversion temperature point has posed
a big problem during solar energy transfer. When solar energy is to be applied, solar radiation in the form of
electromagnetic waves is initially converted into heat on being absorbed by a collector surface and then used to
heat up the system (Magal, 1990, Acra, 1996). Temperature gradients in both convective and non-convective
pool systems play a vital role in the creation of inversion temperature points. These inversion points perturb the
even distribution of energy in these systems. A non-convective pool (solar pond) is a body of water which acts
as a solar collector with integral heat storage for supplying thermal energy. There are two types of solar pond;
the convective and the non-convective solar ponds. A convective solar pond is a shallow body of water with a
large bag that prevents evaporation but permits convectional processes (Dincer and Rosen, 2002). It has a glass
2. The Occurrence Of Successive Temperature Inversions InâŚ
www.ijesi.org 37 | Page
cover on top and a blackened bottom to minimize heat loss. A non-convective solar pond is also a large body
of shallow water between 1 to 5m deep. It is arranged in such a way that the temperature gradient is reversed
from normal incidence. This is to allow the collection of radiant energy, storage of heat and transport of thermal
energy at a temperature of 40-500
C above normal (Hehne and Chen, 1998). Unlike a convective solar pond, a
salt gradient solar pond (SGSP) maintains a layered structure with a defined density gradient that supports
convection and offers thermal insulation effect. Temperature gradient is formed as a result of absorption of solar
radiation at the base of the pool.
Temperature inversion is a natural phenomenon that occurs in both gaseous and liquid media alike. In gaseous
media, these are various types of temperature inversions. These are classified by their positions in the
atmosphere such as elevated or surface-based inversions. The other type is formed from radiation, turbulence or
frontal inversions (Kooi, 1979).
In a liquid medium, the trend is similar to that of a gas. A liquid remains an important object to be
considered as a thermal mass. The liquid temperature is a function of the ambient temperature (Ta) condition and
temperature gradients )(
dx
dT
.This shows that there is an increase in temperature with height (Benjan, 1995).A
liquid layer in which the temperature decreases sharply with height defines the inversion temperature point. At
the point of inversion,
0ď˝
dx
dT
(changes in temperature with height equal zero)
II. MATERIALS AND METHOD
The model non-convective pools were made up of four steel drums inserted with eleven thermometers
each at designated heights measured from their base. The drum is 80cm and the length occupied by the
thermometers between 7cm to 61cm.This process was followed by lagging the drums with insulators of 25cm
thick and the introduction of a volume of water up to a height of 60cm and finally multiple absorbing layers
(plane glass collector covers) were placed, 1-glass for pool 1, 2-glasses for pool 2 , 3-glasses for pool 3 and no
glass for pool 4.The first glass covered the surface of the drum, the second glass and third were separated by a
distance of 10cm from each other. The experimental setup was carried out in an open field devoid of shade and
placed on top of 6 inches thick blocks above the ground. This was to avoid interference and create maximum
solar radiation reception from all angles. The inner surfaces of the pools were painted with black red oxide paint
to conserve heat as described by (Sailullah,A. Z,Shahed,I and Saha,A, 2012 ).The values of temperature
variations with height for the four non-convective pools were monitored between 7am to 6pm daily for a period
of three months cutting across dry and wet seasons. The data were tabulated and a plots was made for specific
days and specific hours (6am) as shown on Fig.1 and Table 1
Height cm Do
temp(O
C)
D1
temp(O
C)
D2
temp(O
C)
D3
temp(O
C)
7.0 26.3 29.0 28.2 28.1
14.0 26.0 30.2 30.0 28.9
21.0 26.0 30.9 28.8 19.3
28.0 25.8 30.9 31.0 30.1
35.0 27.4 28.0 19.0 30.9
42.0 26.5 29.0 30.0 31.0
45.5 25.9 30.0 30.1 31.9
49.0 26.9 19.0 30.9 32.0
52.5 27.0 30.3 29.5 31.5
56.0 26.2 31.0 30.5 31.0
61.0 25.0 32.9 31.3 28.0
3. The Occurrence Of Successive Temperature Inversions InâŚ
www.ijesi.org 38 | Page
III. RESULTS AND DISCUSSION
The result of the investigation into the occurrence of successive inversion temperatures in the non-
convective pools are summarized in Table 1 and Figure 1 below
Table 1: Temperature distribution with height for four
non-convective pools at 6am, Ta = 24o
C on Nov. 22, 2002
Fig. 1 A graph of temperature distribution with height for four
non-convective pools at 6am, Ta = 24o
C on Nov. 22, 2002
The results as shown in both the Table 1and Figure1 above confirm absolute similarity in the nature of
the data and phase of the curves. There is a linear trend in the temperature distribution from the point of
interaction of solar radiation with the bottom of the pools as we migrate from top to bottom and from 6am to
6pm . The distribution of data from the table shows points of successive temperature inversion occurring across
the pools. In pool 1(D1) , inversions occurred at 35cm and 49cm. In pool 2(D2), it occurred at 21cm,35cm and
52.5cm and pool 3(D3), it occurred at 21cm and 45cm.. The trend defines a convolution which affirms
temperature inversions expressed in both convex and concave dimensions. Though there is an absolute
maximum (positive inversion) and an absolute minimum (negative inversion) across the pools and between
6am and 6pm, but the trend of the distribution in pool D1 ,D2and D3 haven prominent inversions at 49cm,35cm
and 21cm respectively. The values of the inversion temperature ranged between 0.1o
C to 10.0o
C for both
prominent and minor inversion.At all levels of the experiment, pool Do, with no layer produced no prominent
inversions temperature points, while pools D1, D2 and D3 specifying one, two and three layers respectively
produced inversions at all prescribed ambient temperatures. This is obvious in view of the fact that, gaseous
temperature inversion occurs at the stratospheric layer of the atmosphere where there is an ionic concentration.
This ionic concentration could be likened to the multiple layered collectors as defined by Macree (1998),
Enumetecal (2005) and Abdul (2011)
IV. CONCLUSION
The research on successive temperature inversions in a non-convective pool subjected to multiple
absorbing layers was meant to investigate the distribution of energy in a pool system based on observed
temperature gradient. The distribution of energy across the four non-convective pools when solar radiation
impinges on the collector surfaces shows irregular non-linear energy transfer. The research reveals that, there is
an undulating trend that is presented in a convex and concave dimension called positive and negative
temperature inversions. The inversions are prominent at designated heights according to the number of
absorbing layers, but there are multiple inversions within a specified pool system. The fall and rise in
4. The Occurrence Of Successive Temperature Inversions InâŚ
www.ijesi.org 39 | Page
temperature that define the inversion points ranges between 0.1o
C to 10o
C across the number of hours under
investigation despite the fact that data and analysis for 1 hour was done.
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