Natural draft cooling towers are very essential in modern days in thermal and nuclear power stations. These are the hyperbolic shells of revolution in form and are supported on inclined columns. Several types of shell supporting structures such as A,V,X,Y are being used for construction of NDCT’s. Wind loading on NDCT governs critical cases and requires attention. In this paper a comparative study on reinforcement details has been done on NDCT’s with X and Y shell supporting structures. For this purpose 166m cooling tower with X and Y supporting structures being analyzed and design for wind (BS & IS code methods), seismic loads using SAP2000.
Parametric Study for Wind Design of Vertical Pressure Vessel as per Indian St...IJMER
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.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Effects of shape on the wind instigate response of high rise buildingseSAT Journals
Abstract A large number of structures that are being constructed at present tend to be wind-sensitive because of their slenderness, shapes, size, lightness and flexibility. With the ever increase in the vertical growth of urban cities, high rise buildings are being constructed in large numbers. In this study, analytical investigation of different shapes of buildings are taken as an example and various analytical approaches are performed on the building. These plans are modeled and wind loads are found out according to I.S 875(part 3)-1987 by taking gust factor and without taking gust factor. These models are compared in different aspects such as storey drift, storey displacement, storey shear, etc. for different shapes of buildings by using finite element software package ETAB’s 13.1.1v. Among these results, which shape of building provide sound wind loading to the structure as well as the structural efficiency would be selected. Key Words: Storey displacement, Storey drift, Storey shear, Gust, Wind load
Effects of welding current and arc voltage on fcaw weld bead geometryeSAT Journals
Abstract Flux cored arc welding(FCAW) process is characterized with its high deposition rate and productivity. Control of the operating parameters in FCAW is essential to obtain high production rates and good quality welds. Bead on plate welds were carried out on mild steel plates to study the influence of welding current and arc voltage on weld bead geometry parameters. The weld bead coss-sections were metallographically investigated. The effects of these welding parameters were evaluated by measuring penetration depth, reinforcement height, bead width, wetting angle, electrod deposit area and plate fusion area. The bead cross-section area and the weld shape factor were calculated from the measured results. The effects of welding parameters on weld bead geometry have been presented by histograms. Key Words: Flux cored arc welding, arc welding parameters, weld bead geometry, weld shape factor
Parametric Study for Wind Design of Vertical Pressure Vessel as per Indian St...IJMER
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.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Effects of shape on the wind instigate response of high rise buildingseSAT Journals
Abstract A large number of structures that are being constructed at present tend to be wind-sensitive because of their slenderness, shapes, size, lightness and flexibility. With the ever increase in the vertical growth of urban cities, high rise buildings are being constructed in large numbers. In this study, analytical investigation of different shapes of buildings are taken as an example and various analytical approaches are performed on the building. These plans are modeled and wind loads are found out according to I.S 875(part 3)-1987 by taking gust factor and without taking gust factor. These models are compared in different aspects such as storey drift, storey displacement, storey shear, etc. for different shapes of buildings by using finite element software package ETAB’s 13.1.1v. Among these results, which shape of building provide sound wind loading to the structure as well as the structural efficiency would be selected. Key Words: Storey displacement, Storey drift, Storey shear, Gust, Wind load
Effects of welding current and arc voltage on fcaw weld bead geometryeSAT Journals
Abstract Flux cored arc welding(FCAW) process is characterized with its high deposition rate and productivity. Control of the operating parameters in FCAW is essential to obtain high production rates and good quality welds. Bead on plate welds were carried out on mild steel plates to study the influence of welding current and arc voltage on weld bead geometry parameters. The weld bead coss-sections were metallographically investigated. The effects of these welding parameters were evaluated by measuring penetration depth, reinforcement height, bead width, wetting angle, electrod deposit area and plate fusion area. The bead cross-section area and the weld shape factor were calculated from the measured results. The effects of welding parameters on weld bead geometry have been presented by histograms. Key Words: Flux cored arc welding, arc welding parameters, weld bead geometry, weld shape factor
Criticality of Gust Pressures on the Members of Self Standing TowersIDES Editor
Tall latticed steel towers are being pursued for the
purpose of microwave transmission, T.V. transmission etc.
Antennas are fixed at the top of the tower for transmission.
The height of the towers may range from 50m to 250m. The
structural form consists of latticed steel work, suitable bracing
and suitable foundation for the tower legs. Usually bolted
connections are provided for the joints. Mainly dead and wind
loads are considered for the design of such towers. The I.S.
Code [8] has given recommendations for force coefficients to
be adopted while estimating the wind force. The force
coefficient depends on the solidity ratio. The design wind
pressure is multiplied by the effective frontal area and the
force coefficient to arrive at the wind force. The code is silent
on the method to be followed to determine the design wind
pressure. The latticed steel towers which have lesser self
weight relative to the height are highly flexible in nature and
under the action of the fluctuating wind the towers vibrate
and undergo large deflections or deformations. Hence the
study of wind-structure dynamic interaction becomes
necessary for accurate assessment of wind effects on towers.
The gust effectiveness factor takes into account the dynamic
properties of the structure, the wind-structure interaction and
then determines the wind loads as equivalent static loads. In
this paper, steel towers of heights ranging from 50m to 250m
are considered for wind load analysis. Wind loads are
determined based on static method as well as gust effectiveness
factor method. The critical gust loads for design are
determined. The variation of wind force with height, geometry
and the dynamic properties of the structure are studied. Based
on the above, important conclusions are drawn. The
conclusions will be useful for safe and rational design of
latticed steel towers.
ANALYSIS OF WIND & EARTHQUAKE LOAD FOR DIFFERENT SHAPES OF HIGH RISE BUILDINGIAEME Publication
Modern tall buildings have efficient structural systems, and utilize high-strength materials, resulting in reduced building height, and thus, become more slender and flexible with low damping. These flexible buildings are very sensitive to wind excitation and earthquake load causing discomfort to the building occupants. Therefore, in order to mitigate such an excitation and to improve the performance of tall buildings against wind loads and earthquake loads, many researches and studies have been performed. Early integration of aerodynamic shaping, wind engineering considerations,
and structural system selections play a major role in the architectural design of a tall building in order to mitigate the building response to the wind excitations.
Influence of Wind Loads on tall buildingsMukul Yambal
This is study project in which IS-875 :part 3 -1987 is compared with IS-875 :part 3 -2009 draft version by IIT-Kgp as well as it is compared with wind provisions in ASCE 7 with an example of Reinforced Concrete (RCC) 10 story frame designed in ETABS 2015.
EFFECT OF SHAPE OF TALL BUILDINGS SUBJECTED TO WIND LOADINGIAEME Publication
Objectives: To study the effect and variation of wind pressure with the shape, rounding of the corners and height of the structure. Methods: Aerodynamic approach is architecture is the extreme approach in the design of tall buildings. In the present thesis, multistory buildings of 40 storey, 60 storey and 80 storey were modelled for different shapes of structures i.e. Rectangular structure, Rectangular structure with rounded corners, Square structure, Square structure with rounded corners, Circular structure and Elliptical structure. Findings: The influence of height and shapes on gust loads and its effects on the response of the structure are studied in the present case. The analysis of the building has been carried out using standard commercial software (STAAD PRO) and the estimation of wind loads is done by Indian standard code IS-875(Part-3). The effect of rounding of the corners of tall structures is studied through computational fluid dynamics (CFD) on pressure distribution on the surface of the structure. Novelty: Standard software fluent is used for CFD analysis.
Structural Behaviors of Reinforced Concrete Dome with Shell System under Vari...ijtsrd
There are many different systems constructing dome structure. Among them, the shell system is the most popular in reinforcement concrete structure in these days. Therefore, it is necessary to know the structural behaviours of it. The objectives of this journal is to study the structural behaviours of the reinforced concrete dome structure with shell system under gravity loading and lateral loading in cyclone wind categories and various seismic zones. Seismic loads are considered from zone 1 to zone 4 based on UBC 1997 .Wind loads are considered from I to V category as cyclone categories. Structural elements of RC dome structure are designed according to Building Code of American Concrete Institute ACI 318 99 . With these member forces obtained from the SAP 2000 analysis, the design for all structural members will be performed according to ACI 318 99. The members of dome structure are designed as an intermediate moment resisting frame. The design of the shell beams is verified by using hand calculations with the output forces under the gravity loading and lateral loading obtained from the SAP2000 analysis. Equivalent static analysis procedure is used in this study. Based on the comparison of analysis results, it can be observed where the maximum deflection occurs along the meridian direction under seismic and wind loading conditions. Then, the axial force of dome structure is significant than any other forces in shell system. From the study of analysis results of both systems, it has been noticed that the bottom ring in shell system is essential to control the forces from the shell area. Khine Zar Aung | Khin Aye Mon | Khin Thanda Htun "Structural Behaviors of Reinforced Concrete Dome with Shell System under Various Loading Conditions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27839.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/27839/structural-behaviors-of-reinforced-concrete-dome-with-shell-system-under-various-loading-conditions/khine-zar-aung
Study Effective of Wind Load on Behavior of ShearWall in Frame StructureIJERA Editor
Wind load is really the result of wind pressures acting on the building surfaces during a wind event. This wind
pressure is primarily a function of the wind speed because the pressure or load increases with the square of the
wind velocity.Structural walls, or shear walls, are elements used to resist lateral loads, such as those generated
by wind and earthquakes. Structural walls are considerably deeper than typical beams or columns. This attribute
gives structural walls considerable in-plane stiffness which makes structural walls a natural choice for resisting
lateral loads. In addition to considerable strength, structural walls can dissipate a great deal of energy if detailed
properly. Walls are an invaluable structural element when protecting buildings from seismic events. Buildings
often rely on structural walls as the main lateral force resisting system. Shear walls are required to perform in
multiple ways. Shear walls can then be designed to limit building damage to the specified degree. The loaddeformation
response of the structural walls must be accurately predicted and related to structural damage in
order to achieve these performance goals under loading events of various magnitudes. The applied load is
generally transferred to the wall by a diaphragm or collector or drag member. The performance of the framed
buildings depends on the structural system adopted for the structure The term structural system or structural
frame in structural engineering refers to load-resisting sub-system of a structure. The structural system
transfers loads through interconnected structural components or members. These structural systems need to be
chosen based on its height and loads and need to be carried out, etc. The selection of appropriate structural
systems for building must satisfy both strength and stiffness requirements. The structural system must be
adequate to resist lateral and gravity loads that cause horizontal shear deformation and overturning deformation.
The efficiency of a structural system is measured in terms of their ability to resist lateral load, which increases
with the height of the frame. A building can be considered as tall when the effect of lateral loads is reflected in
the design. Lateral deflections of framed buildings should be limited to prevent damage to both structural and
nonstructural elements. In the present study, the structural performance of the framed building with shear wall
will be analysis.
Study on Effect of Wind Load and Earthquake Load on Multi-storey RC Framed Bu...IJSRD
Now a day the increase in the construction of tall buildings, residential and commercial sector, and the new trend are towards taller and slender structures. Though the effect of wind and earthquake, forces becoming important for every structural designer to know. Every engineer is facing with the problem of providing stability, strength for loads like lateral loads. That’s the reason wind as well as earthquake loading have become the influential factors in tall buildings. Loads that are lateral loads play important role for drift. The drift must be taken into consideration for tall structure. The above mentioned are some of the key issues which affect the behavior of structure and economy of the building. This thesis focuses the effects of lateral loads on medium and tall buildings the storey forces, displacements, storey shear, story drift every part of are analyzed on every level of height on the building, Indian codal provision gives us the basic wind speed at 10m height for some important cities/towns. However it does not provide for all the cities in India. In the following work attempt is made to find the effect of lateral loads i.e. wind load and earth quake loads for various models having shear walls and without shear wall. For the study a symmetrical building plan is used with 16 storeys and 31 storeys are analyzed and designed by using structure analysis software tool ETABS-2013. The study also includes the determination of base shear, displacement, storey drift, storey forces and the results are compared with them. These parameters have also considers the effect of shear wall. In order to design a structure to resist wind and earthquake loads, the forces on the structure must be specified.
WIND ANALYSIS OF A MULTI STOREY BUILDING WITH AND WITHOUT MASS IRREGURALITY B...Divya Swapna Nallajeru
Structural Analysis is a branch which involves in the determination of behaviour of structures in order to predict the responses of different structural components due to effect of loads. Each and every structure will be subjected to either one or the groups of loads, the various kinds of loads normally considered are dead load, live load, earth quake load and wind load.
ETABS (Extended Three Dimensional Analysis of Building System) is a software which is incorporated with all the major analysis engines that is static, dynamic, Linear and non-linear, etc and especially this Software is used to analyze and design the buildings. Our project “Wind Analysis of a Multi-storey building with and Without Mass Irregularity” is an attempt to analyze a multi storey building with Mass irregularity. A G+10 storey building is considered for this study. Irregularities are not avoidable in construction of buildings; Adequate precautions can be taken. A detailed study of structural behavior of the buildings with irregularities is essential for design and behavior. Civil engineering structures are mainly designed to resist static load. Generally the effect of dynamic loads acting on structure is not considered. This feature of neglecting the dynamic forces sometimes becomes the cause of disaster, Over the last two decades, Wind engineering has increasingly focused on the modest low rise and high rise structures, since much of the damage and financial loss associated with extreme wind events happens to these minimally engineered buildings like low rise buildings and also huge loss if encountered by the high rise buildings. As some of these model- and full - scale wind engineering data filters into the design codes and standards, one may expect to see reduced hurricane/cyclone damage. However, when one combines the more rapid increase in population along the world's tropical coasts with a generally unacceptably low standard of new building construction inspection, it seems quite likely that loss of life, as well as insured and uninsured property losses will continue to be the norm in the foreseeable future. The wind engineering community needs to be more responsible in forcefully transferring our technical knowledge to the designer and builder. In this present work the analysis for G+l0 Reinforced cement concrete building having mass irregularity in 9th floor and building without mass irregularity are analyzed. This thesis highlights the effects on floor which has different loads (mass irregularity) in multistorey building.
Criticality of Gust Pressures on the Members of Self Standing TowersIDES Editor
Tall latticed steel towers are being pursued for the
purpose of microwave transmission, T.V. transmission etc.
Antennas are fixed at the top of the tower for transmission.
The height of the towers may range from 50m to 250m. The
structural form consists of latticed steel work, suitable bracing
and suitable foundation for the tower legs. Usually bolted
connections are provided for the joints. Mainly dead and wind
loads are considered for the design of such towers. The I.S.
Code [8] has given recommendations for force coefficients to
be adopted while estimating the wind force. The force
coefficient depends on the solidity ratio. The design wind
pressure is multiplied by the effective frontal area and the
force coefficient to arrive at the wind force. The code is silent
on the method to be followed to determine the design wind
pressure. The latticed steel towers which have lesser self
weight relative to the height are highly flexible in nature and
under the action of the fluctuating wind the towers vibrate
and undergo large deflections or deformations. Hence the
study of wind-structure dynamic interaction becomes
necessary for accurate assessment of wind effects on towers.
The gust effectiveness factor takes into account the dynamic
properties of the structure, the wind-structure interaction and
then determines the wind loads as equivalent static loads. In
this paper, steel towers of heights ranging from 50m to 250m
are considered for wind load analysis. Wind loads are
determined based on static method as well as gust effectiveness
factor method. The critical gust loads for design are
determined. The variation of wind force with height, geometry
and the dynamic properties of the structure are studied. Based
on the above, important conclusions are drawn. The
conclusions will be useful for safe and rational design of
latticed steel towers.
ANALYSIS OF WIND & EARTHQUAKE LOAD FOR DIFFERENT SHAPES OF HIGH RISE BUILDINGIAEME Publication
Modern tall buildings have efficient structural systems, and utilize high-strength materials, resulting in reduced building height, and thus, become more slender and flexible with low damping. These flexible buildings are very sensitive to wind excitation and earthquake load causing discomfort to the building occupants. Therefore, in order to mitigate such an excitation and to improve the performance of tall buildings against wind loads and earthquake loads, many researches and studies have been performed. Early integration of aerodynamic shaping, wind engineering considerations,
and structural system selections play a major role in the architectural design of a tall building in order to mitigate the building response to the wind excitations.
Influence of Wind Loads on tall buildingsMukul Yambal
This is study project in which IS-875 :part 3 -1987 is compared with IS-875 :part 3 -2009 draft version by IIT-Kgp as well as it is compared with wind provisions in ASCE 7 with an example of Reinforced Concrete (RCC) 10 story frame designed in ETABS 2015.
EFFECT OF SHAPE OF TALL BUILDINGS SUBJECTED TO WIND LOADINGIAEME Publication
Objectives: To study the effect and variation of wind pressure with the shape, rounding of the corners and height of the structure. Methods: Aerodynamic approach is architecture is the extreme approach in the design of tall buildings. In the present thesis, multistory buildings of 40 storey, 60 storey and 80 storey were modelled for different shapes of structures i.e. Rectangular structure, Rectangular structure with rounded corners, Square structure, Square structure with rounded corners, Circular structure and Elliptical structure. Findings: The influence of height and shapes on gust loads and its effects on the response of the structure are studied in the present case. The analysis of the building has been carried out using standard commercial software (STAAD PRO) and the estimation of wind loads is done by Indian standard code IS-875(Part-3). The effect of rounding of the corners of tall structures is studied through computational fluid dynamics (CFD) on pressure distribution on the surface of the structure. Novelty: Standard software fluent is used for CFD analysis.
Structural Behaviors of Reinforced Concrete Dome with Shell System under Vari...ijtsrd
There are many different systems constructing dome structure. Among them, the shell system is the most popular in reinforcement concrete structure in these days. Therefore, it is necessary to know the structural behaviours of it. The objectives of this journal is to study the structural behaviours of the reinforced concrete dome structure with shell system under gravity loading and lateral loading in cyclone wind categories and various seismic zones. Seismic loads are considered from zone 1 to zone 4 based on UBC 1997 .Wind loads are considered from I to V category as cyclone categories. Structural elements of RC dome structure are designed according to Building Code of American Concrete Institute ACI 318 99 . With these member forces obtained from the SAP 2000 analysis, the design for all structural members will be performed according to ACI 318 99. The members of dome structure are designed as an intermediate moment resisting frame. The design of the shell beams is verified by using hand calculations with the output forces under the gravity loading and lateral loading obtained from the SAP2000 analysis. Equivalent static analysis procedure is used in this study. Based on the comparison of analysis results, it can be observed where the maximum deflection occurs along the meridian direction under seismic and wind loading conditions. Then, the axial force of dome structure is significant than any other forces in shell system. From the study of analysis results of both systems, it has been noticed that the bottom ring in shell system is essential to control the forces from the shell area. Khine Zar Aung | Khin Aye Mon | Khin Thanda Htun "Structural Behaviors of Reinforced Concrete Dome with Shell System under Various Loading Conditions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27839.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/27839/structural-behaviors-of-reinforced-concrete-dome-with-shell-system-under-various-loading-conditions/khine-zar-aung
Study Effective of Wind Load on Behavior of ShearWall in Frame StructureIJERA Editor
Wind load is really the result of wind pressures acting on the building surfaces during a wind event. This wind
pressure is primarily a function of the wind speed because the pressure or load increases with the square of the
wind velocity.Structural walls, or shear walls, are elements used to resist lateral loads, such as those generated
by wind and earthquakes. Structural walls are considerably deeper than typical beams or columns. This attribute
gives structural walls considerable in-plane stiffness which makes structural walls a natural choice for resisting
lateral loads. In addition to considerable strength, structural walls can dissipate a great deal of energy if detailed
properly. Walls are an invaluable structural element when protecting buildings from seismic events. Buildings
often rely on structural walls as the main lateral force resisting system. Shear walls are required to perform in
multiple ways. Shear walls can then be designed to limit building damage to the specified degree. The loaddeformation
response of the structural walls must be accurately predicted and related to structural damage in
order to achieve these performance goals under loading events of various magnitudes. The applied load is
generally transferred to the wall by a diaphragm or collector or drag member. The performance of the framed
buildings depends on the structural system adopted for the structure The term structural system or structural
frame in structural engineering refers to load-resisting sub-system of a structure. The structural system
transfers loads through interconnected structural components or members. These structural systems need to be
chosen based on its height and loads and need to be carried out, etc. The selection of appropriate structural
systems for building must satisfy both strength and stiffness requirements. The structural system must be
adequate to resist lateral and gravity loads that cause horizontal shear deformation and overturning deformation.
The efficiency of a structural system is measured in terms of their ability to resist lateral load, which increases
with the height of the frame. A building can be considered as tall when the effect of lateral loads is reflected in
the design. Lateral deflections of framed buildings should be limited to prevent damage to both structural and
nonstructural elements. In the present study, the structural performance of the framed building with shear wall
will be analysis.
Study on Effect of Wind Load and Earthquake Load on Multi-storey RC Framed Bu...IJSRD
Now a day the increase in the construction of tall buildings, residential and commercial sector, and the new trend are towards taller and slender structures. Though the effect of wind and earthquake, forces becoming important for every structural designer to know. Every engineer is facing with the problem of providing stability, strength for loads like lateral loads. That’s the reason wind as well as earthquake loading have become the influential factors in tall buildings. Loads that are lateral loads play important role for drift. The drift must be taken into consideration for tall structure. The above mentioned are some of the key issues which affect the behavior of structure and economy of the building. This thesis focuses the effects of lateral loads on medium and tall buildings the storey forces, displacements, storey shear, story drift every part of are analyzed on every level of height on the building, Indian codal provision gives us the basic wind speed at 10m height for some important cities/towns. However it does not provide for all the cities in India. In the following work attempt is made to find the effect of lateral loads i.e. wind load and earth quake loads for various models having shear walls and without shear wall. For the study a symmetrical building plan is used with 16 storeys and 31 storeys are analyzed and designed by using structure analysis software tool ETABS-2013. The study also includes the determination of base shear, displacement, storey drift, storey forces and the results are compared with them. These parameters have also considers the effect of shear wall. In order to design a structure to resist wind and earthquake loads, the forces on the structure must be specified.
WIND ANALYSIS OF A MULTI STOREY BUILDING WITH AND WITHOUT MASS IRREGURALITY B...Divya Swapna Nallajeru
Structural Analysis is a branch which involves in the determination of behaviour of structures in order to predict the responses of different structural components due to effect of loads. Each and every structure will be subjected to either one or the groups of loads, the various kinds of loads normally considered are dead load, live load, earth quake load and wind load.
ETABS (Extended Three Dimensional Analysis of Building System) is a software which is incorporated with all the major analysis engines that is static, dynamic, Linear and non-linear, etc and especially this Software is used to analyze and design the buildings. Our project “Wind Analysis of a Multi-storey building with and Without Mass Irregularity” is an attempt to analyze a multi storey building with Mass irregularity. A G+10 storey building is considered for this study. Irregularities are not avoidable in construction of buildings; Adequate precautions can be taken. A detailed study of structural behavior of the buildings with irregularities is essential for design and behavior. Civil engineering structures are mainly designed to resist static load. Generally the effect of dynamic loads acting on structure is not considered. This feature of neglecting the dynamic forces sometimes becomes the cause of disaster, Over the last two decades, Wind engineering has increasingly focused on the modest low rise and high rise structures, since much of the damage and financial loss associated with extreme wind events happens to these minimally engineered buildings like low rise buildings and also huge loss if encountered by the high rise buildings. As some of these model- and full - scale wind engineering data filters into the design codes and standards, one may expect to see reduced hurricane/cyclone damage. However, when one combines the more rapid increase in population along the world's tropical coasts with a generally unacceptably low standard of new building construction inspection, it seems quite likely that loss of life, as well as insured and uninsured property losses will continue to be the norm in the foreseeable future. The wind engineering community needs to be more responsible in forcefully transferring our technical knowledge to the designer and builder. In this present work the analysis for G+l0 Reinforced cement concrete building having mass irregularity in 9th floor and building without mass irregularity are analyzed. This thesis highlights the effects on floor which has different loads (mass irregularity) in multistorey building.
A cooling tower is a heat rejection device which extracts waste heat to the atmosphere through the cooling of a water stream to a lower temperature.
A cooling tower is a heat rejection device which extracts waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature.
Common applications include cooling the circulating water used in oil refineries, petrochemical and other chemical plants, thermal power stations and HVAC systems for cooling buildings. The classification is based on the type of air induction into the tower: the main types of cooling towers are natural draft and induced draft cooling towers.
Cooling towers vary in size from small roof-top units to very large hyperboloid structures (as in the adjacent image) that can be up to 200 metres (660 ft) tall and 100 metres (330 ft) in diameter, or rectangular structures that can be over 40 metres (130 ft) tall and 80 metres (260 ft) long. The hyperboloid cooling towers are often associated with nuclear power plants,[1] although they are also used to some extent in some large chemical and other industrial plants. Although these large towers are very prominent, the vast majority of cooling towers are much smaller, including many units installed on or near buildings to discharge heat from air conditioning.
PRINCIPAL OF COOLING TOWER
TYPES OF COOLING TOWER
DIFFERENT TERMS USED IN COOLING TOWER SPECIFICATION
AIR PROPERTIES AND
SIZING OF COOLING TOWER HEIGHT
TYPICAL SPECIFICATION FORMAT / DATASHEET
Cooling Tower:-By Using More Efficient Equipment Increase EfficiencyMayursinh Solanki
This Project Is Done Over ONGC Hazira Plant At Phase-I Cooling Tower.In This Slide Show,We Want To Give You Some New Ideas About Equipment Like Fills,Drift Eliminator,Storage Tank,ect.
Performance Analysis of the Natural Draft Cooling Tower in Different SeasonsIOSR Journals
Cooling towers are the biggest heat and mass transfer devices that are in widespread use. In this
paper we use a natural draft counter flow cooling tower in investigating the performance of cooling tower in
different seasons. The humidity is defined as water particles present in air. The humidity is the major factor in
the atmosphere, it depends upon ambient temperature. Humidity is high in winter season and low in summer
season.
The performance of the natural draft cooling tower is dominated by wind speed, ambient air
temperatures and humidity in the atmospheric conditions. When the humidity is high in atmosphere, large
quantity of water is required for cooling condensate. When humidity is low in atmosphere, small quantity of
water is required for cooling condensate. The value of relative humidity in the atmosphere varies from place to
place and season. The different losses in the cooling tower such as drift losses, evaporation losses and blow
down losses can be calculated. The maintenance of cooling tower in the form of removal of scale or corrosion
plays important role in the performance of the tower. The performance of the natural draft cooling tower of 500
MW is evaluated.
In this Thesis I will try to understand the concept associated with cooling towers and model a laboratory sized cooling tower in a software package called Engineering Equation Solver (EES). An example of system modelling is presented in this progress report, along with the comparison of a set of results with an experimental data from P.A Hilton Model H892 Bench top cooling tower with a maximum of 9% error. A user interface is also modelled to simulate off-design performance rather than conducting experiments. It also allows you to do additional scenarios that cannot be practically being done in lab,
like Relative humidity, etc.
Analysis of forced draft cooling tower performance using ansys fluent softwareeSAT Journals
Abstract In this project the cooling tower performance has been analyzed by varying air inlet parameters with different air inlet angles and by attaching a nozzle in air inlet. The cooling tower analyzed here is used specifically for small scale industries, which is forced draft counter-flow cooling tower with single module capacities from 10 to 100 cooling tons. In this project 50 tons cooling capacity model has been taken as reference model. The analysis has been done using computational fluid dynamics (CFD) ANSYS 14.5 software. The cooling tower models have been modeled using SOLIDWORKS 2013 software and they have been meshed using ICEM CFD 14.5 software. The meshed models have been analyzed using FLUENT software. The air inlet angles varied in horizontal direction, vertical direction and by combining both horizontal and vertical inclination. A convergent nozzle has been modeled and assembled to the inlet pipe. The temperature contours of the cooling tower models have been taken from the analysis. Based on the outlet cold water temperature, the improved effectiveness of the cooling tower model has been obtained.
Keywords: Forced draft cooling tower, Air inlet parameter, Convergent nozzle, Cooling ton capacity, Counter flow cooling tower, Ansys 14.5, Solidworks 2013, ICEM CFD 14.5, Effectiveness of cooling tower.
Finite element analysis of hyperbolic coolingsagmech24
Natural draught cooling towers are widely used in modern thermal and nuclear power plants. Because of their shear size and susceptibility to horizontal stresses, these towers with very thin shell thickness are unique constructions. The boundary conditions should be regarded as free at the top and fixed at the bottom. The cooling tower's material characteristics include a young modulus of 31GPa and a Poisson Ratio of 0.15. Finite Element Analysis was used to analyse these cooling towers for seismic and wind stresses. Wind loads on these cooling towers have been estimated in the form of pressures using the design wind pressure coefficients as supplied in IS: 11504-1985 code together with the design wind pressures at different levels as specified in IS: 875 (Part 3) - 1987 code. Ansys 18.2 was used to conduct the analysis. The study yields maximum deflection and maximum equivalent stress.
Analysis of Cantilever Steel Chimney As Per Indian StandardsIJERA Editor
Chimneys are tall and slender structures which are used to discharge waste/flue gases at higher elevation with sufficient exit velocity such that the gases and suspended solids(ash) are dispersed in to the atmosphere over a defined spread such that their concentration , on reaching the ground is within acceptable limits specified by pollution control regulatory authorities. This paper summarizes the analysis and design concepts of chimneys as per Indian codal provisions incorporation was also made through finite element analysis. Effect of inspection manhole on the behavior of Cantilever steel chimney, two chimney models one with the manhole and other without manhole were taken into consideration. These models are analyzed by finite element software STAAD Pro, emphasis also placed on effect of geometric limitations on the design aspects in designing chimney.
Design analysis & comparsion of intze type water tank for different wind ...eSAT Journals
Abstract Any design of Water Tanks is subjected to Dead Load + Live Load and Wind Load or Seismic Load as per IS codes of Practices. Most of the times tanks are designed for Wind Forces and not even checked for Earthquake Load assuming that the tanks will be safe under seismic forces once designed for wind forces. In this study Wind Forces and Seismic Forces acting on an Intze Type Water tank for Indian conditions are studied. The effect of wind on the elevated structures is of prime importance as Wind flows relative to the surface of ground and generates loads on the structures standing on ground. Most of the designers consider the wind effect and neglect the seismic effect on the structure. The Indian Standard Code IS 875(Part-3) 2003 and IS 1893-2000 for Wind & Seismic effect is used in this study. The Elevated Structure is designed for various Wind forces i.e. 39 m/s, 44 m/s, 47 m/s & 50 m/s and the same is cross checked with different Seismic Zones i.e. Zone-II, Zone-III, Zone-IV, & Zone-V by ‘Response Spectrum Method’ and the maximum governing condition from both the forces is further used for design & analysis of staging. It is found from the analysis that the Total load, Total moments and Reinforcement in staging i.e. Columns, Braces & also for Raft foundation varies for Case-1, Case-2, Case-3 & Case-4. Key Words: Wind Load, Seismic Load, Intze Tank, and I.S.Codes etc…
Detailed design procedure for solar panel mounting structure with dual axis tracking capability for Sub urban West Bengal(Wind load calculation have been done for this region only).
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.
Beaglebone Black Webcam Server For SecurityIJTET Journal
Web server security using BeagleBone Black is based on ARM Cortex-A8 processor and Linux operating system
is designed and implemented. In this project the server side consists of BeagleBone Black with angstrom OS and interfaced
with webcam. The client can access the web server by proper authentication. The web server displays the web page forms
like home, video, upload, settings and about. The home web page describes the functions of Web Pages. The video Web page
displays the saved videos in the server and client can view or download the videos. The upload web page is used by the client
to upload the files to server. The settings web page is used to change the username, password and date if needed. The about web page provides the description of the project
Biometrics Authentication Using Raspberry PiIJTET Journal
Biometric authentication is one of the most popular and accurate technology. Nowadays, it is used in many real time
applications. However, recognizing fingerprints in Linux based embedded computers (raspberry pi) is still a very complex problem.
This entire work is done on the Linux based embedded computer called raspberry pi , in which database creation and management
using postgresql, web page creation using PHP language, fingerprint reader access, authentication and recognition using python were
entirely done on raspberry pi This paper discusses on the standardized authentication model which is capable of extracting the
fingerprints of individual and store that in database . Then I use the final fingerprint to match with others in fingerprints present in the
database (postgresql) to show the capability of this model.
Conceal Traffic Pattern Discovery from Revealing Form of Ad Hoc NetworksIJTET Journal
Number of techniques has been planned supported packet secret writing to safeguard the
communication in MANETs. STARS functioning supported stastical characteristics of captured raw traffic.
STARS discover the relationships of offer to destination communication. To forestall STAR attack associate
offer hidding technique is introduced.The pattern aims to derive the source/destination probability distribution.
that's the probability for each node to entire traffic captured with link details message source/destination and
conjointly the end-to-end link probability distribution that's the probability for each strive of nodes to be
associate end-to-end communication strive. thence construct point-to-point traffic originate and then derive the
end-to-end traffic with a set of traffic filtering rules; thus actual traffic protected against revelation attack.
Through this protective mechanism efficiency of traffic enlarged by ninety fifth from attacked traffic. For a lot of
sweetening to avoid overall attacks second shortest path is chosen.
Node Failure Prevention by Using Energy Efficient Routing In Wireless Sensor ...IJTET Journal
The most necessary issue that has to be solved in coming up with an information transmission rule for
wireless unplanned networks is a way to save unplanned node energy whereas meeting the wants of applications
users because the unplanned nodes are battery restricted. Whereas satisfying the energy saving demand, it’s
conjointly necessary to realize the standard of service. Just in case of emergency work, it's necessary to deliver the
information on time. Achieving quality of service in is additionally necessary. So as to realize this demand, Power -
efficient Energy-Aware routing protocol for wireless unplanned networks is planned that saves the energy by
expeditiously choosing the energy economical path within the routing method. When supply finds route to
destination, it calculates α for every route. The worth α is predicated on largest minimum residual energy of the trail
and hop count of the trail. If a route has higher α, then that path is chosen for routing the information. The worth of α
are higher, if the most important of minimum residual energy of the trail is higher and also the range of hop count is
lower. Once the trail is chosen, knowledge is transferred on the trail. So as to extend the energy potency any
transmission power of the nodes is additionally adjusted supported the situation of their neighbour. If the neighbours
of a node are closely placed thereto node, then transmission vary of the node is diminished. Thus it's enough for the
node to own the transmission power to achieve the neighbour at intervals that vary. As a result transmission power
of the node is cut back that later on reduces the energy consumption of the node. Our planned work is simulated
through Network machine (NS-2). Existing AODV and Man-Min energy routing protocol conjointly simulated
through NS-2 for performance comparison. Packet Delivery quantitative relation, Energy Consumption and end-toend
delay.
Prevention of Malicious Nodes and Attacks in Manets Using Trust worthy MethodIJTET Journal
In Manet the first demand is co-operative communication among nodes. The malicious nodes might cause security issues like grey hole and cooperative attacks. To resolve these attack issue planning Dynamic supply routing mechanism, that is referred as cooperative bait detection theme (CBDS) that integrate the advantage of each proactive and reactive defence design is used. In region attacks, a node transmits a malicious broadcast informing that it's the shortest path to the destination, with the goal of intercepting messages. During this case, a malicious node (so-called region node) will attract all packets by victimisation solid Route Reply (RREP) packet to incorrectly claim that “fake” shortest route to the destination then discard these packets while not forwarding them to the destination. In grey hole attacks, the malicious node isn't abs initio recognized in and of itself since it turns malicious solely at a later time, preventing a trust-based security resolution from detective work its presence within the network. It then by selection discards/forwards the info packets once packets undergo it. During this we have a tendency to focus is on detective work grey hole/collaborative region attacks employing a dynamic supply routing (DSR)-based routing technique.
Effective Pipeline Monitoring Technology in Wireless Sensor NetworksIJTET Journal
Wireless detector nodes are a promising technology to play three-dimensional applications. Even it
will sight correct lead to could on top of ground and underground. In solid underground watching system makes
some challenges are there to propagating the signals. The detector node is moving entire the underground
pipeline and sending information to relay node that's placed within the on top of ground. If any relay node is
unsuccessful during this condition suggests that it'll not sending the info. In this watching system can specially
designed as a heterogeneous networks. Every high power relay nodes most covers minimum 2 low power relay
node. If any relay node is unsuccessful within the network, the constellation can modification mechanically
supported the heterogeneous network. The high power relay node is change the unsuccessful node and sending
the condition of pipeline. The benefits are thought-about to be extremely distributed, improved packet delivery
Raspberry Pi Based Client-Server Synchronization Using GPRSIJTET Journal
A low cost Internet-based attendance record embedded system for students which uses wireless technology to
transfer data between the client and server is designed. The proposed system consist of a Raspberry Pi which acts as a
client which stores the details of the students in the database by using user login system using web. When the user logs
into the database the data is sent through GPRS to the server machine which maintains the records of the employees and
the attendance is updated in the server database. The GPRS module provides a bidirectional real-time data transfer
between the client and server. This system can be implemented to any real time application so as to retrieve information
from a data source of the client system and send a file to the remote server through GPRS. The main aim is to avoid the
limitations in Ethernet connection and design a low cost and efficient attendance record system where the data is
transferred in a secure way from the client database and updated in the server database using GPRS technology
ECG Steganography and Hash Function Based Privacy Protection of Patients Medi...IJTET Journal
Data hiding can hide sensitive information into signals for covert communication. Most data hiding
techniques will distort the signal in order to insert additional messages. The distortion is often small; the irreversibility is
not admissible to some sensitive techniques. Most of the applications, lossless data hiding is desired to extract the
embedded data and the original host signal. The project proposes the enhancement of protection system for secret data
communication through encrypted data concealment in ECG signals of the patient. The proposed encryption technique
used to encrypt the confidential data into unreadable form and not only enhances the safety of secret carrier information by
making the information inaccessible to any intruder having a random method. For that we use twelve square ciphering
techniques. The technique is used make the communication between the sender and the receiver to be authenticated is hash
function. To evaluate the effectiveness of ECG wave at the proposed technique, distortion measurement techniques of two
are used, the percentage residue difference (PWD) and wavelets weighted PRD. Proposed technique provides high security protection for patient data with low distortion is proven in this proposed system.
An Efficient Decoding Algorithm for Concatenated Turbo-Crc CodesIJTET Journal
In this paper, a hybrid turbo decoding algorithm is used, in which the outer code, Cyclic Redundancy Check code is
not used for detection of errors as usual but for error correction and improvement. This algorithm effectively combines the iterative
decoding algorithm with Rate-Compatible Insertion Convolution Turbo Decoding, where the CRC code and the turbo code are
regarded as an integrated whole in the Decoding process. Altogether we propose an effective error detecting method based on
normalized Euclidean distance to compensate for the loss of error detection capability which should have been provided by CRC
code. Simulation results show that with the proposed approach, 0.5-2dB performance gain can be achieved for the code blocks
with short information length
Improved Trans-Z-source Inverter for Automobile ApplicationIJTET Journal
In this paper a new technology is proposed with a replacement of conventional voltage source/current
source inverter with Improved Trans-Z-source inverter in automobile applications. The improved Trans-Z-source
inverter has a high boost inversion capability and continues input current. Also this new inverter can suppress the
resonant current at the startup; this resonant current in the startup may lead the device to permanent damage. In
improved Trans-Z-source inverter a couple inductor is needed, instead of this coupled inductor a transformer is used.
By using a transformer with sufficient turns ratio the size can be reduced. The turn’s ratio of the transformer decides
the input voltage of the inverter. In this paper operating principle, comparison with conventional inverters, working
with automobiles simulation results, THD analysis, Hardware implementation using ATMEGA 328 P are included.
Wind Energy Conversion System Using PMSG with T-Source Three Phase Matrix Con...IJTET Journal
This paper presents an analysis of a PMSG wind power system using T-Sourcethree phase matrix converter. PMSG using T-Source three phase matrix converterhas advantages that it can provide any desired AC output voltage regardless of DC input with regulation in shoot-through time. In this control system T-Source capacitor voltage can be kept stable with variations in the shoot-through time, maximum power from the wind turbine to be delivered. Inaddition, of a new future, the converter employs a safe-commutation strategy toconduct along a continuous current flow, which results in theelimination of voltage spikes on switches without the need for a snubber circuit. With the use of matrix converter the surely need forrectifier circuit and passive components to store energy arereduced. The MATLAB/Simulinkmodel of the overall system is carried out and theoretical wind energy conversion output load voltage calculations are madeand feasibility of the new topology has been verified and that theconverter can produce an output voltage and output current. This proposed method has greater efficiency and lower cost.
Comprehensive Path Quality Measurement in Wireless Sensor NetworksIJTET Journal
A wireless sensor network mostly relies on multi-hop transmissions to deliver a data packet. It is of essential importance to measure the quality of multi-hop paths and such information shall be utilized in designing efficient routing strategies. Existing metrics like ETF, ETX mainly focus on quantifying the link performance in between the nodes while overlooking the forwarding capabilities inside the sensor nodes. By combining the QoF measurements within a node and over a link, we are able to comprehensively measure the intact path quality in designing efficient multihop routing protocols. We propose QoF, Quality of Forwarding, a new metric which explores the performance in the gray zone inside a node left unattended in previous studies. We implement QoF and build a modified Collection Tree Protocol.
Optimizing Data Confidentiality using Integrated Multi Query ServicesIJTET Journal
Query services have experienced terribly massive growth within past few years for that reason large usage of services need to balance outsourcing data management to Cloud service providers that provide query services to the client for data owners, therefore data owner needs data confidentiality as well as query privacy to be guaranteed attributable to disloyal behavior of cloud service provider consequently enhancing data confidentiality must not be compromise the query processed performance. It is not significant to provide slow query services as the result of security along with privacy assurance. We propose the random space perturbation data perturbation method to provide secure with kNN(k-nearest-neighbor) range query services for protecting data in the cloud and Frequency Structured R-Tree (FSR-Tree) efficient range query. Our schemes enhance data confidentiality without compromising the FSR-TREE query processing performance that also increases the user experience.
Foliage Measurement Using Image Processing TechniquesIJTET Journal
Automatic detection of fruit and leaf diseases is essential to automatically detect the symptoms of diseases as early as they appear on the growing stage. This system helps to detect the diseases on fruit during farming , right from plan and easily monitoring the diseases of grapes leaf and apple fruit. By using this system we can avoid the economical loss due to various diseases in agriculture production. K-means clustering technique is used for segmentation. The features are extracted from the segmented image and artificial neural network is used for training the image database and classified their performance to the respective disease categories. The experimental results express that what type of disease can be affected in the fruit and leaf .
Harmonic Mitigation Method for the DC-AC Converter in a Single Phase SystemIJTET Journal
This project suggest a sine-wave modulation technique is to achieve a low total harmonic distortion of Buck-Boost converter connected to a changing polarity inverter in a system. The suggested technique improves the harmonic content of the output. In addition, a proportional-resonant Integral controller is used along with harmonic compensation techniques for eliminating the DC component in the system. Also, the performance of the Proposed controller is analyzed when it connecting to the converter. The design of Buck-Boost converter is fed by modulated sine wave Pulse width modulation technique are proposed to mitigate the low order harmonics and to control the output current. So, that the output complies within the standard limit without use of low pass filter.
Experimental Investigation of Lateral Pressure on Vertical Formwork Systems u...IJTET Journal
The modeling of pressure distribution of fresh concrete poured in vertical formwork are rather dynamic than complex. Many researchers had worked on the pressure distribution modeling of concrete and formulated empirical relationship factors like formwork height, rate of pour, consistency classes of concrete. However, in the current scenario, most of high rise construction uses self compacting concrete(SCC) which is a special concrete which utilizes not only mineral and chemical admixtures but also varied aggregate proportions and hence modeling pressure distribution of SCC over other concrete in vertical formwork systems is necessitated. This research seeks to bridge the gap between the theoretical formulation of pressure distribution with the actual modeled (scaled) vertical formwork systems. The pressure distribution of SCC in the laboratory will be determined using pressure sensors, modeled and analyzed.
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
A Comprehensive Approach for Multi Biometric Recognition Using Sclera Vein an...IJTET Journal
Sclera and finger print vein fusion is a new biometric approach for uniquely identifying humans. First, Sclera vein is identified and refined using image enhancement techniques. Then Y shape feature extraction algorithm is used to obtain Y shape pattern which are then fused with finger vein pattern. Second, Finger vein pattern is obtained using CCD camera by passing infrared light through the finger. The obtained image is then enhanced. A line shape feature extraction algorithm is used to get line patterns from enhanced finger vein image. Finally Sclera vein image pattern and Finger vein image pattern were combined to get the final fused image. The image thus obtained can be used to uniquely identify a person. The proposed multimodal system will produce accurate results as it combines two main traits of an individual. Therefore, it can be used in human identification and authentication systems.
Study of Eccentrically Braced Outrigger Frame under Seismic ExitationIJTET Journal
Outrigger braced structures has efficient structural form consist of a central core, comprising braced frames with
horizontal cantilever ”outrigger” trusses or girders connecting the core to the outer column. When the structure is loaded
horizontally, vertical plane rotation of the core is restrained by the outriggers through tension in windward column and
compression in leeward column. The effective structural depth of the building is greatly increased, thus augmenting the lateral
stiffness of the building and reducing the lateral deflections and moments in core. In effect, the outriggers join the columns to the
core to make the structure behave as a partly composite cantilever. By providing eccentrically braced system in outrigger frame by
varying the size of links and analyzing it. Push over analysis is carried out by varying the link size using computer programs, Sap
2007 to understand their seismic performance. The ductile behavior of eccentrically braced frame is highly desirable for structures
subjected to strong ground motion. Maximum stiffness, strength, ductility and energy dissipation capacity are provided by
eccentrically braced frame. Studies were conducted on the use of outrigger frame for the high steel building subjected to
earthquake load. Braces are designed not to buckle, regardless of the severity of lateral loading on the frame. Thus eccentrically
braced frame ensures safety against collapse.
Enhanced Hashing Approach For Image Forgery Detection With Feature Level FusionIJTET Journal
Image forgery detection and its accuracy are addressed in the proposed work. The image authentication process aims at finding the originality of an image. Due to the advent of many image editing software image tampering has become common. The Enhanced hashing approach is suggested for image authentication. The concept of Hashing has been used for searching images from large databases. It can also be applied to image authentication as it produces different results with respect to the change in image. But the hashing methods used for similarity searches cannot be used for image authentication since they are no sensitive for small changes. Moreover, we need a system that detects only perceptual changes. A new hashing method, namely, enhanced robust hashing is proposed for image authentication, which uses global and local properties of an image. This method is developed for detecting image forgery, including removal, insertion, and replacement of objects, and abnormal color modification, and for locating the forged area. The local models include position and texture information of object regions in the image. The hash mechanism uses secret keys for encryption and decryption. IP tracing is done to track the suspicious nodes.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdf
Comparative Study on NDCT with Different Shell Supporting Structures
1. INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY
VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303
59
Comparative Study on NDCT with Different Shell
Supporting Structures
K.Vignesh1
M.Ramesh Kannan2
Graduate Student, Division of Structural Engineering Assistant Professor, Division of Structural Engineering
School of Mechanical and Building Sciences School of Mechanical and Building Sciences
VIT Chennai, Chennai, India VIT Chennai, Chennai India
vignesh.k2013@vit.ac.in rameshkannan.m@vit.ac.in
Abstract— Natural draft cooling towers are very essential in modern days in thermal and nuclear power stations. These are the
hyperbolic shells of revolution in form and are supported on inclined columns. Several types of shell supporting structures such
as A,V,X,Y are being used for construction of NDCT’s. Wind loading on NDCT governs critical cases and requires attention.
In this paper a comparative study on reinforcement details has been done on NDCT’s with X and Y shell supporting structures.
For this purpose 166m cooling tower with X and Y supporting structures being analyzed and design for wind (BS & IS code
methods), seismic loads using SAP2000.
Index terms—Geometry, Raker Columns, SAP2000V17.0, Sandwich method, Soil Loads, Wind Pressure.
—————————— ——————————
1.INTRODUCTION
A cooling tower is a structure which is designed for the
evaporative cooling of water where hot water gets cooled by direct
contact with air. Cooling towers are subjected to its self-weight
and the dynamic load such as an earthquake motion and a wind
effects. In the absence of earthquake loading, wind constitutes the
main loading for the design of natural draught cooling towers. The
shell structure is supported on inclined raker columns. There are
several types of columns such as A,V,X,I,Y etc. The columns used
for the cooling tower should withstand the self-weight of the
structure and the loads acting on the structure. Therefore a
comparative study on analysis and design has been done on
cooling towers with X and Y supporting structures considering
wind loads.
N.Prabakar [1] gave a brief description about the working
principle and salient features of the cooling towers and the loads
considered in cooling towers such as dead load, wind forces, soil
pressure, earthquake loads and temperature loads. the shell
reinforcement gives the clear idea about the stress distribution in
circumferential and meridional surface. Dieter Buscha
, Reinhard
Harteb
, Wilfried B. Kra¨tzig c
, Ulrich Montagd
[2] has given a clear
idea in design of 200m cooling tower here the stress distribution
between the meridional and circumferential direction. In this paper
it shows the description of geometry and followed by elucidation
of the conceptual shape optimization. A.M. Nasira
, D.P.
Thambiratnama
, D. Butler b
, P. Austinb
[3] in this paper the
hyperbolic tower is analyzed and the behavior of the tower is
studied under earthquake loading. maximum meridional stress
resultants and lateral deflection of the shell is found out. Tejas G.
Gaikwad, N. G. Gore, V. G. Sayagavi, Kiran Madhavi, Sandeep
Pattiwar[4] this paper gives an idea about the behavior of cooling
tower in wind load conditions. Gust and peak winds methods are
adopted in finding the wind pressure along the height and
circumferential. Hoop stress is greatly affected by the changes in
shell curvature. G. Murali, C. M. Vivek Vardhan and B. V.
Prasanth Kumar Reddy [5] in this paper three different cooling
towers of varying height and parameters are being analyzed for
wind loads and the optimization of the towers is done by
comparing the meridional and circumferential stress resultants.
2.SALIENT FEATURES OF TOWER
The shell structure consist of two hyperbolic shell of
revolution both meeting at the throat of the cooling tower. The
overall height of the cooling tower is 166m, it consist of varying
thickness throughout the height of the structure. The top diameter
of the tower is 79m, diameter of throat level is 78.5m, base
diameter of the shell is 125.6m, height of throat from sill level is
about 124.5m, and height of raker columns with respect to sill
level is 9.81m. The geometry of hyperbola is derived from the
equation of hyperbola with respect to the height of tower.
The tower shell is supported on inclined raker columns. There
are several types of raker columns such as A,V,X,I and Y. In this
paper X and Y raker columns are used for analysis and design.
raker columns consists of inclined circular columns and pedestals.
The diameter of circular column is 1.4m and 1.2m and size of
pedestal is 3mx1.5m and 3.5mx1.8m for X and Y columns
respectively. The tower foundation consists of annular raft
foundation is about 3mx1.8m in depth.
2.1. Geometry of Hyperbolic Curve
The hyperbolic curve is derived from the hyperbolic equation.
NDCT are mostly designed as thin shell structures supported along
2. INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY
VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303
60
the circumference by a system of columns. Here the tower is
designed for variation of thickness over the height of the tower.
TABLE1
Variation of Radius and Thickness Along the Height.
Fig1. Cooling tower specifications. Tower specifications with top, throat and
bottom radius.
3. LOADS
Hyperbolic cooling towers may be subjected to various
loading such as dead load, wind loads, earthquake loads,
temperature loads and soil loads. For the proportioning of
elements in cooling towers the effect of various loading conditions
should be factored and combined as per codes and standards.
The loads considered for analysis and design of NDCT are
dead loads, wind loads, and soil loads. The effects of these loads
are factored and combined by using BS4485-4-1996 codes and
IS875-3-1987.
c.1. Wind Forces
Wind forces are the major externally applied force in design
of cooling towers. In this paper the gust and mean wind forces
applied on NDCT as per IS875-3-1987 and BS4485-4-1996.
3.1.1. IS 875-3-1987 Gust Wind Procedure
In this procedure actual design wind speed is calculated from
the product of k1, k2 and k3 with basic wind speed. The wind
pressure is calculated along the height of the tower and along the
circumference of the tower. The basic wind speed is chosen as per
the location of the tower, the risk coefficient (K1) is taken as per
IS875, and the terrain category (K2) is taken as per table 33 of
IS875 and topography factor (K3) is taken as 1 as per IS875.
Pressure coefficient, Cp is calculated as per IS11504-1985. Gust
effectiveness factor and interference factor should be multiplied
with design pressure to get actual design pressure.
actual design pressure, PZ = 0.6 x (VB.K1.K2.K3)2
.CP.GF.IF
3.1.2. IS 875-3-1987 Mean Wind Procedure
In this procedure actual design wind speed is calculated from
the product of k1, k2 and k3 with basic wind speed. The wind
pressure is calculated along the height of the tower and along the
circumference of the tower. The basic wind speed is chosen as per
the location of the tower, the risk coefficient (K1) is taken as per
IS875, and the terrain category (K2) is taken as per table 2 of
IS875 and topography factor (K3) is taken as 1 as per IS875.
Pressure coefficient, Cp is calculated as per IS11504-1985.
Interference factor should be multiplied with design pressure to get
actual design pressure.
actual design pressure, PZ = 0.6 x (VB.K1.K2.K3)2
.CP.IF
3.1.3. BS 4485-4-1996 Gust Wind Procedure
In this procedure site wind speed is calculated from the
product of k1, k2 and k3 with basic wind speed. The design mean
wind speed is calculated by product of site wind speed(Vs) and
gust wind factor (Sgz). The wind pressure is calculated along the
height of the tower and along the circumference of the tower.
Pressure coefficient, Cp is calculated as per BS4485-4-1996.
actual design pressure, PZ = 0.613 x (Vgz)2
.CP
3.1.4. BS 4485-4-1996 Mean Wind Procedure
In this procedure site wind speed is calculated from the
product of k1, k2 and k3 with basic wind speed. The design mean
wind speed is calculated by product of site wind speed(Vs) and
mean wind factor (Smz). The wind pressure is calculated along the
height of the tower and along the circumference of the tower.
Pressure coefficient, Cp is calculated as per BS4485-4-1996.
actual design pressure, PZ = 0.613 x (Vmz)2
.CP
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Fig2. Circumferential net wind pressure distribution.
The wind pressure outside the shell is assumed to be
symmetrical about the centre line in the direction of wind. The
wind pressure is calculated as per IS11504-1985 and BS4485-2-
1996. The pressure distribution is calculated over the height of the
tower.
P1
= Σ Fncosnϴ
c.2. Soil Pressure
Raker columns are constructed usually below the ground level.
The ground level lies on the top level of the pedestal. The total
load from the shell transferred to foundation through raker
columns. The soil load can be calculated as vertical and inclined
portion that acts on the foundation and pedestals.
c.3. Load Combination
The various design loads should be combined in accordance
with the relevant design codes. Whichever combination provides
maximum effect to the building or structure should be concerned
for the design. In this paper the loads considered are dead load,
wind loads and soil loads. The load combination is in accordance
with IS456-2007and BS4485-4-1986.
Load combinations as per IS456-2007
a) 1.5 Dead load + 1.5 IS Gust wind + 1.5 soil vertical
b) 0.9 Dead load + 0.9 IS Gust wind + 0.9 soil vertical
Load combinations as per BS4485-4-1996
For design of tower shells:
c) Dead load + 1.5ΦG BS Mean wind + soil vertical
d) 1.4 Dead load + 1.5ΦG BS Mean wind + 1.4 soil vertical
For design of raker columns
e) Dead load + 1.5ΦF BS Mean wind + soil vertical
f) 1.4 Dead load + 1.5ΦF BS Mean wind + 1.4 soil vertical
ΦG, ΦF- wind amplification factors should be evaluated using
meridional stress resultants from the windward side of the tower.
ΦG is for the tower shell, here the tower shell is divided into three
parts as per BS4485-4-1996. ΦF is for the shell supporting
structures (i.e) raker columns which is evaluated at a height above
the base of the shell equal to the distance between adjacent shell
support nodes.
4. DESIGN ASPECTS
4.1. Analysis
The analysis of the towers are challenging task for a
structural designer because of their shape combined with non-
axisymmetric horizontal loads. In this paper the tower is modeled
and analyzed using SAP2000 V17.0. The tower is divided into 105
slices of horizontal plates. Hence each horizontal slice is divided
into 288 shell areas. The advantage of the finite element model of
tower is that the structural modeling can include raker columns
and tower foundations. Two sets of tower is being model one with
X supporting structure and the other with Y supporting structure.
The loads considered for the analysis of both the towers are dead
loads, wind loads, soil loads. The behavior of the two towers has
been studied by using the mode shapes and frequencies of the
respective towers.
Fig 3. Frequency vs time period
Frequency of first mode of tower with X shaped raker columns is
0.86815 cyc/sec, similarly frequency of the first mode of tower
with Y shaped raker column is 0.955 cyc/sec. as per IS875-3-
1987 buildings and closed structures with a height to minimum
lateral dimension ratio of more than about 5.0 and buildings and
closed structures whose natural frequency in the first mode -is
less than 1 Hz. Any building or structure which does not satisfy
either of the above two criteria shall be examined for dynamic
effects of wind. In this paper the tower with Y shaped raker
column is much stiffened when compare to tower with X shaped
raker columns.
4.2. Shell Design
The shell design is generally governed by the direct
tension and moment acting on the section due to dead load, wind
load and soil loads. In this paper the design of hyperbolic shells
are done using eurocode EN1992-2-2005. Sandwich method is
adopted to design the shells. In this method the shells are divided
into three layers upper layer, shear layer and lower layers and a
total of eight forces will act on the shell. In this method out of
plane forces are also should be taken into account for design of
shells. The outer layer carries the membrane action and the inner
layers carry the shear forces.
4.3. Shell Reinforcement
Shell reinforcement will be in meridional and
circumferential direction. The shell reinforcement is very sensitive
to wind loads. In this paper the shell reinforcement is compared
between the towers with X and Y raker columns. Usually the
reinforcements in the meridional govern more when compare to
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circumferential. But circumferential reinforcements hold the
meridional reinforcements and prevent from displacements.
Fig4. Circumferential Vs Meridional top reinforcement
Fig5. Circumferential Vs Meridional bottom reinforcement
In the above figure it clearly shows that meridional reinforcements
govern the circumferential reinforcements. But the circumferential
reinforcements will be provided outside the meridional
reinforcements in order to hold the total compression and tension
forces in the meridional reinforcements.
Fig 6. Circumferential top reinforcement
From the above graph it clearly shows that tower with Y raker
columns governs more area of steel when compare to tower with
X raker columns but over a small scale. From the height of 80m to
120m both the towers have minimum area of steel.
Fig7. Circumferential bottom reinforcement
From the above graph it clearly shows that tower with X raker
columns governs more area of steel when compare to tower with
Y raker columns.
Fig8. Meridional top reinforcement
From the above graph it clearly shows that tower with X raker
columns governs more area of steel when compare to tower with
Y raker columns.
Fig9. Meridional bottom reinforcement
From the above graph it clearly shows that tower with X raker
columns governs more area of steel when compare to tower with
Y raker columns.
4.4. Column Design
The column design is generally governed by axial loads
acting on the column due to load combinations. The loads that take
place on the columns are dead load, wind loads and soil loads acts
on the pedestals. There are two types of columns short and long
columns. Columns are designed as short columns when the ratio of
effective length to the breadth or depth is less than 12 similarly for
long columns when the ratio between the effective length and
breadth or depth of column is greater than 12. In this paper all the
columns are designed as short columns as per SP16-1980.
Fig10. Circular columns
here the Y type of columns governs more area of steel when
compare to X type of columns due to its axial force and the
percentage of reinforcement 0.8% for X type column and it 1.8%
for Y type column.
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Fig11. Rectangular columns
Here the Y type of columns governs more area of steel when
compare to X type of columns. The percentage of reinforcement is
0.8% and its same for both the X type columns and Y type
columns. Due to geometric parameters there is increase in the area
of steel.
4.5. Foundation Design
The load of the structure is being transferred to foundation
through raker columns. The type of foundation adopted is anular
raft foundation. It’s a ring type foundation. The foundation is
being designed for the maximum moments occur in the face of the
column. And the area of steel is provided for the concerned
moments. Minimum reinforcements are provided for both tower
with X type columns and Y type columns.
5. CONCLUSION
Cooling towers are exceptional structures which require
special expertise in design. Since its huge structure the quantity of
the structure will also be high. Proper selection of parameters and
elements will reduce the quantity of the structure. This paper
shows the behavior of the towers with respect to wind forces, self-
weight and soil loads and the design of hyperbolic shells using
sandwich method. This paper emphasizes the idea of using the
proper columns for the towers. The hyperbolic shell is rests on the
raker columns which distributes the loads from the towers to the
foundation. So a proper care should be taken in selection of raker
columns. In this paper it shows that tower with X type of columns
governs more steel when compare to tower with Y type of
columns.
REFERENCES
[1] N.Prabakar (1990), Gammon india, “Structural Design Aspects of
Cooling Tower”.
[2] Dieter Buscha
, Reinhard Harteb
, Wilfried B. Kra¨tzig c
, Ulrich
Montagd
(2002), “New natural draft cooling tower of 200 m of
height”.
[3] A.M. Nasira
, D.P. Thambiratnama
, D. Butler b
, P. Austinb
(2001),
“Dynamics of axisymmetric hyperbolic shell structures”.
[4] Tejas G. Gaikwad, N. G. Gore, V. G. Sayagavi, Kiran Madhavi,
Sandeep Pattiwar (2014), “Effect of wind loading on analysis of
natural draft hyperbolic cooling tower”
[5] G. Murali, C. M. Vivek Vardhan and B. V. Prasanth Kumar Reddy
(2012) “Response of Cooling Towers to Wind Loads”
[6] BS4485-4-1996 “Water cooling towers code of practice for
structural design and construction”
[7] BS6399-2-1997 “ Loading for buildings code of practice for wind
loads”
[8] EN1992-2-2005 “Design of concrete structures, concrete bridges,
design and detailing rules.
[9] IS11504-1985 “Criteria for structural design of reinforced
concrete natural draft cooling towers”
[10] IS875-3-1987 “code of practice for design loads for buildings and
structures,part-3 wind loads”
[11] SP16-1980 “Design aids for reinforced concrete to IS456:2000”