Dr.Gurunadh Velidi | University of petroleum & energy studies (original) (raw)

Papers by Dr.Gurunadh Velidi

This is Describes about the Operational Aspects of Combined Cycle Power Plant, Main concentration... more This is Describes about the Operational Aspects of Combined Cycle Power Plant, Main concentration is on Performance Analysis and Thermodynamic aspects of all the sub systems. The effective heat utilization and accounting of Exergy in the work consumable devices and work extractable. The improvement aspects of various power plants based on combined cycle has been discussed. This book contains the information regarding the working, improving the efficiency of a combined cycle power plant through exergy analysis. In the combined cycle power plants,natural gas is used as major fuel. These plants can achieve higher efficiency in converting fuel to electricity which makes it possible for relatively high priced fuel like natural gas to be competitive for intermediate or base loads.

While nuclear energy has been very influential in meeting the energy needs of Earth, it also has ... more While nuclear energy has been very influential in meeting the energy needs of Earth, it also has implications and uses in outer space exploration. Nuclear energy can be used as a source of power for various space mission in space or on planetary/space platforms and more importantly it can be used for propulsion in order to achieve high specific impulses to allow the spacecraft to reach its destinations faster. This chapter discusses the use of nuclear energy for propulsion in spacecraft and also as a source of power for space missions. While nuclear energy has been used since 1960s in space missions in various forms, many new techniques also have been developed in the last 10 years, which may pave the way for future space missions that will allow mankind to reach further destinations and to establish long-term outposts in space. As long as Le Reve Des Toiles’ or the Dream of Stars continues to be the main dynamo of mankind, nuclear energy in space applications will be at the forefro...

Currently, medical scans yield large 3D data volumes. To analyze the data, image processing techn... more Currently, medical scans yield large 3D data volumes. To analyze the data, image processing techniques are worth employing. Also, the data could be visualized to offer non-invasive and accurate 3D anatomical views regarding the inside of patients. Through this visualization approach, several medical processes or healthcare diagnostic procedures (including virtual reality (VR) aided operations) can be supported. The main aim of this study has been to discuss and provide a critical review of some of the recent scholarly insights surrounding the subject of CFD simulations with applications of VR-aided health care diagnostics. The study’s specific objective has been to unearth how CFD simulations have been applied to different areas of health care diagnostics, with VR environments on the focus. Some of the VR-based health care areas that CFD simulations have been observed to gain increasing application include medical device performance and diseases or health conditions such as colorect...

The Multigrid methods are invented in 1960’s. The solutions for the many physical phenomena will ... more The Multigrid methods are invented in 1960’s. The solutions for the many physical phenomena will lie in their governing equations. Finding solution to these types of equations will depend on the complexity of the problem. Thus solution for many phenomena was solved only after the invention of the computers. Moreover with the help of the techniques for solving like multigrid methods helped researchers obtain the solution to most of the equations. But the solutions for many equations in physics are not yet available. Multigrid methods are the supporting features to solve those equations by solving them with much lesser numerical effort. Recently solving the physics equations with greater speeds without losing accuracy is the custom that has developed. And more importantly solving Navier Stokes equations has been a challenge for past many years in the field of Fluid dynamics. Thus there is a need not only to solve these equations but also to achieve maximum accuracy along with greater ...

Air Defence is one of the most important concepts related to the defence of a nation. It is not p... more Air Defence is one of the most important concepts related to the defence of a nation. It is not possible to protect a country without having full control over its national airspace. The presence of airspace superiority gives that particular nation a superiority in not only national defence but also in projecting power to the neighbouring nations as well. It is one of the reasons why countries like Russia, Israel, India and Turkey can project power to hostile neighbouring nations due to their superiority in air force capabilities and technologies. However, as strong as an offensive capability of an Air Force of a Nation may be, the real capability also lies in the ability to defend against airpower threats and power projections by air. In order to achieve this, there must be non-offensive air defence capability which comprises of long range detection and illumination of targets including air force assets such as attack planes, bombers, missiles and rockets. This can be done as a stan...

The main aim of this study is to discuss and critically review the concept of computational intel... more The main aim of this study is to discuss and critically review the concept of computational intelligence in relation to the context of fluid dynamics in healthcare industries. The motivation or specific objective is to discern how, in the recent past, scholarly investigations have yielded insights into the CI concept as that which is shaping the understanding of fluid dynamics in healthcare. Also, the study strives to predict how CI might shape fluid dynamics understanding in the future of healthcare industries. From the secondary sources of data that have been consulted, it is evident that the CI concept is gaining increasing adoption and application in healthcare fluid dynamics. Some of the specific areas where it has been applied include the determination of occlusion device performance, the determination of device safety in cardiovascular medicine, the determination of optimal ventilation system designs in hospital cleanrooms and operating rooms, and the determination of the eff...

In this paper, we focus on the importance of using computational engineering techniques as well a... more In this paper, we focus on the importance of using computational engineering techniques as well as computational fluid dynamics techniques for better results in mechanical engineering streams at undergraduate level. This is important, as the new breed of engineers need to be well versed in computational engineering techniques since the days of using a paper and pencil for designing are long over. Nowadays, the most important tool for an engineer is the computer and the various computational software and techniques that is associated with it. This paper will emphasize the importance of computational engineering education at undergraduate level and it will be demonstrated from examples from various mechanical engineering streams.

Annales de chimie Science des Matériaux

The purpose of the current research is to investigate the computational heat transfer coefficient... more The purpose of the current research is to investigate the computational heat transfer coefficients of SiO2 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW) by volume and evaluate the influence of base fluid. The thermophysical properties of SiO2, based nanoparticles dispersed in 60EGW and 40EGW base fluid were taken from available literature and regression analysis was performed for formulating equations. The theoretical data was used as input in computational analysis for the investigation of heat transfer coefficients. The results indicate that the heat transfer coefficients for SiO2/60EGW and SiO2/40EGW based nanofluids have shown an enhancement of 25% and 55% respectively when compared with base fluids. Hence, it can be concluded that SiO2/40EGW nanofluids show a better heat transfer rates than SiO2/60EGW nanofluids. RÉSUMÉ. L'objet de la recherche actuelle est d'étudier les coefficients de transfert de chaleur calculé s de nanoparticules de SiO2 dispersé es dans des mélanges d'éthylène glycol (EG) et d'eau (W) à 60 :40 (60EGW) et 40 :60 (40EGW) en volume, et d'é valuer de fluide de base. Les proprié té s thermo physiques de nanoparticules à base de SiO2, dispersé es dans un fluide de base 60EGW et 40EGW ont é té tiré es de la litté rature disponible et une analyse de ré gression a é té ré alisé e pour la formulation d'é quations. Les donné es thé oriques ont é té utilisé es comme entré e dans l'analyse informatique pour l'é tude des coefficients de transfert de chaleur. Les ré sultats indiquent que les coefficients de transfert de chaleur pour les nano fluides à base de SiO2 / 60EGW et de SiO2 / 40EGW ont montré une amé lioration de 25% et 55% respectivement par rapport aux fluides de base. On peut donc en conclure que les nano fluides SiO2 / 40EGW pré sentent un meilleur taux de transfert de chaleur que les nano fluides SiO2 / 60EGW.

In the advancing world of today, the demand for clean and reliable electricity is constantly incr... more In the advancing world of today, the demand for clean and reliable electricity is constantly increasing. With restrains on carbon emissions and with the reduction of fossil fuel reserves; the need of the hour is efficient nuclear power plants. With this paper, it is demonstrated that with modular helium cooled reactors using spherical fuel elements; it is possible to increase the efficiency of the reactor cycle with a safer nuclear process control. In addition, it is also demonstrated that parallel to electricity production, conversion of methane to hydrogen will be carried out simultaneously, thus decreasing the operational cost of such a nuclear power plant.

Abstract—In the current evolution of advanced technologies, the need for solving technical proble... more Abstract—In the current evolution of advanced technologies, the need for solving technical problems with complex systems in a reasonable period of time is growing rapidly. We need to have tools that makes an engineering student to understand the particular design's working conditions before he or she can change the model or improve the design. Especially with innovative minds, there are many ideas and solutions with various engineering problems; but the only barrier is a dynamic platform which will allow them to ...

Abstract-As long as the demand for worldwide energy continues, the need for nuclear energy will a... more Abstract-As long as the demand for worldwide energy continues, the need for nuclear energy will always be in the forefront of the energy sector. However, Fukushima tribulations require us to look for safer and more efficient ways of designing nuclear power plants. Hence, it is essential to look for advanced ways of creating special types of nuclear reactors that work outside conventional parameters. Gas core nuclear reactors are such reactors which allow the use of gaseous nuclear fuels for fission while allowing for reduction in ...

drguven.info

With the increase in power demand, India’s infrastructure is growing at tremendous speed in conco... more With the increase in power demand, India’s infrastructure is growing at tremendous speed in concordance with its growth rate. Indian is looking to strengthen its capabilities in both economic front and industrial front. In order to overcome future challenges, it has to sustain its energy demand with nuclear energy. This paper describes the ways to reach the future prospective of India where nuclear energy is instrumental in strengthening both financial resources and industrial establishment. The study on existing facilities in India to meet its future plans will be an interesting part of the paper. The major requirements for a successful nuclear program are the availability of nuclear fuel, processing facilities, supporting manpower, technology, equipment, as well as experts to carry out future research. By looking at the past experiences, India is looking for facilities to create its own manpower from various universities since capable and professional nuclear manpower is the key t...

Article history: Received 9 August 2018 Received in revised form 15 September 2018 Accepted 20 Se... more Article history: Received 9 August 2018 Received in revised form 15 September 2018 Accepted 20 September 2018 Available online 6 November 2018 The purpose of the current research is to investigate the friction factors for SiO2 and Al2O3 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW). Apart from the influence of nanoparticles, the thermal conductivity, temperature and viscosity of base fluids also has an impact on the enhancement of thermal conductivity of nanofluids. The trends shown by the nanofluid in enhancing the heat transfer is due to the fact that the nanoparticles present in the base fluid increases the thermal conductivity and the viscosity of the base liquid at the same time. Different solvers and turbulence models are used to try to determine the most accurate CFD method for predicting friction factor in plain tube heat exchanger. Therefore, the enhancement of thermal conductivity leads to increase in the heat tra...

ABSTRACT One of the most important criteria in a successful space program is the concept of havin... more ABSTRACT One of the most important criteria in a successful space program is the concept of having a reusable spacecraft that can successfully survive numerous reentry conditions. The reentry of most of reusable space shuttles resembles a flat plate at high angles of attack because of its flat windward surface. The feasibility of a concave ventral surface in space shuttles is investigated computationally with a commercially available computational fluid dynamics solver Ansys fluent 13.0. A full three dimensional Navier stokes equations are solved over a thin concave plate at different angles of attack to a hypersonic flow and the total heat transfer rates, stagnation heat fluxes and drag coefficients are compared with that of a thin flat plate normal to the flow. The length, breadth and thickness of the flat plate are 1m, 1m and 10 cm respectively. The flat plate is bent along its longitudinal axis to obtain concave surface with different eccentricities varying from 1 to 10. The free stream conditions used in the simulation are that of earth's atmosphere at an altitude of 60 km and Mach number 20. The air is assumed to be composed of real gases in chemical non equilibrium and the laminar finite rate chemistry is simulated using 5 species 17 reaction model. The flow is assumed to be continuum. The angle of attack is varied from 75 degrees to 90 degrees while sideslip angle and roll angles are fixed at zero degree. The peak heat fluxes and total heat transfer rates for concave plate is compared with that of flat plate with no concavity. This paper discusses the results of these simulations and how these results can be utilized for a more successful shuttle type spacecraft in the future.

Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in th... more Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in the power generation. Helium as a coolant is more effective in exchanging heat between fuel pebbles and the coolant and maintains good advection ratio in the core. However, one of the more important points in nuclear power generation is to increase the heat production rate as much as possible. But, in real life, all nuclear reactors are bound in their maximum efficiency by the Carnot cycle. Hence, the only thing that can be done is to increase the heat transfer gradients in order to help increase the overall efficiency of the heat production system in a nuclear reactor. One of the most effective ways of increasing the heat transfer capacity to a flow is to utilize turbulence and therefore increase the amount of heat that is being transferred from the fuel pebble, which is undergoing the fission reaction, to the coolant itself. Naturally, various adverse pressure gradients which will become predominant in energized turbulent boundary layers, will also have to be taken into account. This paper will address the effect of boundary layer formation on energy exchange and heat interaction within the core. Moreover, the flow conditions that are designed over the fuel pebbles with grater turbulence will help to improve the energy exchange between the nuclear fuel pebble and the coolant. In this paper, we will demonstrate the added heat ratios with the help of CFD simulations with Helium as the coolant and it will address the effectiveness of energy exchange with the help of boundary layer formation over nuclear spherical fuel pebbles in gas cooled reactors.

From the past many decades, many researches have worked on different airfoils for getting the eff... more From the past many decades, many researches have worked on different airfoils for getting the efficient lift. Lift and drag are the two factors on ehich aerodynamic efficiency is based on. These can be determined by the pressure distibution over the airfoil.. Pressure distribution depends on the free stream velocity of air around the airfoil. At low Reynolds number, velocity of flow of an airfoil is lower then the velocity of flow at high Reynolds number, which is a reason for the decrease in the lift. So, to increase the performance of airfoil at low Reynolds number, there are some methods involved like airfoil shaping, boundary layer control and also by increasing the flow speeds over the blades. In the present work, an airfoil is designed by taking the computational approach and lift variations are studied for the airfoil at low Reynolds numbers. Then the lift variations are again studied at low Reynolds number by involving the above mentioned methods. Viscous flow analysis is us...

Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in th... more Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in the power generation. Helium as a coolant is more effective in exchanging heat between fuel pebbles and the coolant and maintains good advection ratio in the core. However, one of the more important points in nuclear power generation is to increase the heat production rate as much as possible. But, in real life, all nuclear reactors are bound in their maximum efficiency by the Carnot cycle. Hence, the only thing that can be done is to increase the heat transfer gradients in order to help increase the overall efficiency of the heat production system in a nuclear reactor. One of the most effective ways of increasing the heat transfer capacity to a flow is to utilize turbulence and therefore increase the amount of heat that is being transferred from the fuel pebble, which is undergoing the fission reaction, to the coolant itself. Naturally, various adverse pressure gradients which will become...

In the present work, investigation of various turbulence models has been carried out for predicti... more In the present work, investigation of various turbulence models has been carried out for predicting the efficient turbulence model for a two-dimensional nozzle designed for a supersonic cruise nozzle. Initially, a computational domain was created for a two-dimensional nozzle for a supersonic cruise, then, with an appropriate mesh size, various turbulence models has been used for simulations. The main objective of the present work is to determine the efficient turbulence model for nozzle designs. As till date, commercial software's are implementing many advanced technique, the test of turbulence model is very much needed for today's research. The results obtained from the computational approach were compared with experimental approach which was conducted in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.8 to 1.2 by NASA Langley Research Centre, Virginia. These supersonic cruise nozzles have a wide range of applications in designing Fighter jets and supersonic cru...

This is Describes about the Operational Aspects of Combined Cycle Power Plant, Main concentration... more This is Describes about the Operational Aspects of Combined Cycle Power Plant, Main concentration is on Performance Analysis and Thermodynamic aspects of all the sub systems. The effective heat utilization and accounting of Exergy in the work consumable devices and work extractable. The improvement aspects of various power plants based on combined cycle has been discussed. This book contains the information regarding the working, improving the efficiency of a combined cycle power plant through exergy analysis. In the combined cycle power plants,natural gas is used as major fuel. These plants can achieve higher efficiency in converting fuel to electricity which makes it possible for relatively high priced fuel like natural gas to be competitive for intermediate or base loads.

While nuclear energy has been very influential in meeting the energy needs of Earth, it also has ... more While nuclear energy has been very influential in meeting the energy needs of Earth, it also has implications and uses in outer space exploration. Nuclear energy can be used as a source of power for various space mission in space or on planetary/space platforms and more importantly it can be used for propulsion in order to achieve high specific impulses to allow the spacecraft to reach its destinations faster. This chapter discusses the use of nuclear energy for propulsion in spacecraft and also as a source of power for space missions. While nuclear energy has been used since 1960s in space missions in various forms, many new techniques also have been developed in the last 10 years, which may pave the way for future space missions that will allow mankind to reach further destinations and to establish long-term outposts in space. As long as Le Reve Des Toiles’ or the Dream of Stars continues to be the main dynamo of mankind, nuclear energy in space applications will be at the forefro...

Currently, medical scans yield large 3D data volumes. To analyze the data, image processing techn... more Currently, medical scans yield large 3D data volumes. To analyze the data, image processing techniques are worth employing. Also, the data could be visualized to offer non-invasive and accurate 3D anatomical views regarding the inside of patients. Through this visualization approach, several medical processes or healthcare diagnostic procedures (including virtual reality (VR) aided operations) can be supported. The main aim of this study has been to discuss and provide a critical review of some of the recent scholarly insights surrounding the subject of CFD simulations with applications of VR-aided health care diagnostics. The study’s specific objective has been to unearth how CFD simulations have been applied to different areas of health care diagnostics, with VR environments on the focus. Some of the VR-based health care areas that CFD simulations have been observed to gain increasing application include medical device performance and diseases or health conditions such as colorect...

The Multigrid methods are invented in 1960’s. The solutions for the many physical phenomena will ... more The Multigrid methods are invented in 1960’s. The solutions for the many physical phenomena will lie in their governing equations. Finding solution to these types of equations will depend on the complexity of the problem. Thus solution for many phenomena was solved only after the invention of the computers. Moreover with the help of the techniques for solving like multigrid methods helped researchers obtain the solution to most of the equations. But the solutions for many equations in physics are not yet available. Multigrid methods are the supporting features to solve those equations by solving them with much lesser numerical effort. Recently solving the physics equations with greater speeds without losing accuracy is the custom that has developed. And more importantly solving Navier Stokes equations has been a challenge for past many years in the field of Fluid dynamics. Thus there is a need not only to solve these equations but also to achieve maximum accuracy along with greater ...

Air Defence is one of the most important concepts related to the defence of a nation. It is not p... more Air Defence is one of the most important concepts related to the defence of a nation. It is not possible to protect a country without having full control over its national airspace. The presence of airspace superiority gives that particular nation a superiority in not only national defence but also in projecting power to the neighbouring nations as well. It is one of the reasons why countries like Russia, Israel, India and Turkey can project power to hostile neighbouring nations due to their superiority in air force capabilities and technologies. However, as strong as an offensive capability of an Air Force of a Nation may be, the real capability also lies in the ability to defend against airpower threats and power projections by air. In order to achieve this, there must be non-offensive air defence capability which comprises of long range detection and illumination of targets including air force assets such as attack planes, bombers, missiles and rockets. This can be done as a stan...

The main aim of this study is to discuss and critically review the concept of computational intel... more The main aim of this study is to discuss and critically review the concept of computational intelligence in relation to the context of fluid dynamics in healthcare industries. The motivation or specific objective is to discern how, in the recent past, scholarly investigations have yielded insights into the CI concept as that which is shaping the understanding of fluid dynamics in healthcare. Also, the study strives to predict how CI might shape fluid dynamics understanding in the future of healthcare industries. From the secondary sources of data that have been consulted, it is evident that the CI concept is gaining increasing adoption and application in healthcare fluid dynamics. Some of the specific areas where it has been applied include the determination of occlusion device performance, the determination of device safety in cardiovascular medicine, the determination of optimal ventilation system designs in hospital cleanrooms and operating rooms, and the determination of the eff...

In this paper, we focus on the importance of using computational engineering techniques as well a... more In this paper, we focus on the importance of using computational engineering techniques as well as computational fluid dynamics techniques for better results in mechanical engineering streams at undergraduate level. This is important, as the new breed of engineers need to be well versed in computational engineering techniques since the days of using a paper and pencil for designing are long over. Nowadays, the most important tool for an engineer is the computer and the various computational software and techniques that is associated with it. This paper will emphasize the importance of computational engineering education at undergraduate level and it will be demonstrated from examples from various mechanical engineering streams.

Annales de chimie Science des Matériaux

The purpose of the current research is to investigate the computational heat transfer coefficient... more The purpose of the current research is to investigate the computational heat transfer coefficients of SiO2 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW) by volume and evaluate the influence of base fluid. The thermophysical properties of SiO2, based nanoparticles dispersed in 60EGW and 40EGW base fluid were taken from available literature and regression analysis was performed for formulating equations. The theoretical data was used as input in computational analysis for the investigation of heat transfer coefficients. The results indicate that the heat transfer coefficients for SiO2/60EGW and SiO2/40EGW based nanofluids have shown an enhancement of 25% and 55% respectively when compared with base fluids. Hence, it can be concluded that SiO2/40EGW nanofluids show a better heat transfer rates than SiO2/60EGW nanofluids. RÉSUMÉ. L'objet de la recherche actuelle est d'étudier les coefficients de transfert de chaleur calculé s de nanoparticules de SiO2 dispersé es dans des mélanges d'éthylène glycol (EG) et d'eau (W) à 60 :40 (60EGW) et 40 :60 (40EGW) en volume, et d'é valuer de fluide de base. Les proprié té s thermo physiques de nanoparticules à base de SiO2, dispersé es dans un fluide de base 60EGW et 40EGW ont é té tiré es de la litté rature disponible et une analyse de ré gression a é té ré alisé e pour la formulation d'é quations. Les donné es thé oriques ont é té utilisé es comme entré e dans l'analyse informatique pour l'é tude des coefficients de transfert de chaleur. Les ré sultats indiquent que les coefficients de transfert de chaleur pour les nano fluides à base de SiO2 / 60EGW et de SiO2 / 40EGW ont montré une amé lioration de 25% et 55% respectivement par rapport aux fluides de base. On peut donc en conclure que les nano fluides SiO2 / 40EGW pré sentent un meilleur taux de transfert de chaleur que les nano fluides SiO2 / 60EGW.

In the advancing world of today, the demand for clean and reliable electricity is constantly incr... more In the advancing world of today, the demand for clean and reliable electricity is constantly increasing. With restrains on carbon emissions and with the reduction of fossil fuel reserves; the need of the hour is efficient nuclear power plants. With this paper, it is demonstrated that with modular helium cooled reactors using spherical fuel elements; it is possible to increase the efficiency of the reactor cycle with a safer nuclear process control. In addition, it is also demonstrated that parallel to electricity production, conversion of methane to hydrogen will be carried out simultaneously, thus decreasing the operational cost of such a nuclear power plant.

Abstract—In the current evolution of advanced technologies, the need for solving technical proble... more Abstract—In the current evolution of advanced technologies, the need for solving technical problems with complex systems in a reasonable period of time is growing rapidly. We need to have tools that makes an engineering student to understand the particular design's working conditions before he or she can change the model or improve the design. Especially with innovative minds, there are many ideas and solutions with various engineering problems; but the only barrier is a dynamic platform which will allow them to ...

Abstract-As long as the demand for worldwide energy continues, the need for nuclear energy will a... more Abstract-As long as the demand for worldwide energy continues, the need for nuclear energy will always be in the forefront of the energy sector. However, Fukushima tribulations require us to look for safer and more efficient ways of designing nuclear power plants. Hence, it is essential to look for advanced ways of creating special types of nuclear reactors that work outside conventional parameters. Gas core nuclear reactors are such reactors which allow the use of gaseous nuclear fuels for fission while allowing for reduction in ...

drguven.info

With the increase in power demand, India’s infrastructure is growing at tremendous speed in conco... more With the increase in power demand, India’s infrastructure is growing at tremendous speed in concordance with its growth rate. Indian is looking to strengthen its capabilities in both economic front and industrial front. In order to overcome future challenges, it has to sustain its energy demand with nuclear energy. This paper describes the ways to reach the future prospective of India where nuclear energy is instrumental in strengthening both financial resources and industrial establishment. The study on existing facilities in India to meet its future plans will be an interesting part of the paper. The major requirements for a successful nuclear program are the availability of nuclear fuel, processing facilities, supporting manpower, technology, equipment, as well as experts to carry out future research. By looking at the past experiences, India is looking for facilities to create its own manpower from various universities since capable and professional nuclear manpower is the key t...

Article history: Received 9 August 2018 Received in revised form 15 September 2018 Accepted 20 Se... more Article history: Received 9 August 2018 Received in revised form 15 September 2018 Accepted 20 September 2018 Available online 6 November 2018 The purpose of the current research is to investigate the friction factors for SiO2 and Al2O3 nanoparticles dispersed in ethylene glycol (EG) and water (W) mixtures in 60:40 (60EGW) and 40:60 (40EGW). Apart from the influence of nanoparticles, the thermal conductivity, temperature and viscosity of base fluids also has an impact on the enhancement of thermal conductivity of nanofluids. The trends shown by the nanofluid in enhancing the heat transfer is due to the fact that the nanoparticles present in the base fluid increases the thermal conductivity and the viscosity of the base liquid at the same time. Different solvers and turbulence models are used to try to determine the most accurate CFD method for predicting friction factor in plain tube heat exchanger. Therefore, the enhancement of thermal conductivity leads to increase in the heat tra...

ABSTRACT One of the most important criteria in a successful space program is the concept of havin... more ABSTRACT One of the most important criteria in a successful space program is the concept of having a reusable spacecraft that can successfully survive numerous reentry conditions. The reentry of most of reusable space shuttles resembles a flat plate at high angles of attack because of its flat windward surface. The feasibility of a concave ventral surface in space shuttles is investigated computationally with a commercially available computational fluid dynamics solver Ansys fluent 13.0. A full three dimensional Navier stokes equations are solved over a thin concave plate at different angles of attack to a hypersonic flow and the total heat transfer rates, stagnation heat fluxes and drag coefficients are compared with that of a thin flat plate normal to the flow. The length, breadth and thickness of the flat plate are 1m, 1m and 10 cm respectively. The flat plate is bent along its longitudinal axis to obtain concave surface with different eccentricities varying from 1 to 10. The free stream conditions used in the simulation are that of earth's atmosphere at an altitude of 60 km and Mach number 20. The air is assumed to be composed of real gases in chemical non equilibrium and the laminar finite rate chemistry is simulated using 5 species 17 reaction model. The flow is assumed to be continuum. The angle of attack is varied from 75 degrees to 90 degrees while sideslip angle and roll angles are fixed at zero degree. The peak heat fluxes and total heat transfer rates for concave plate is compared with that of flat plate with no concavity. This paper discusses the results of these simulations and how these results can be utilized for a more successful shuttle type spacecraft in the future.

Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in th... more Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in the power generation. Helium as a coolant is more effective in exchanging heat between fuel pebbles and the coolant and maintains good advection ratio in the core. However, one of the more important points in nuclear power generation is to increase the heat production rate as much as possible. But, in real life, all nuclear reactors are bound in their maximum efficiency by the Carnot cycle. Hence, the only thing that can be done is to increase the heat transfer gradients in order to help increase the overall efficiency of the heat production system in a nuclear reactor. One of the most effective ways of increasing the heat transfer capacity to a flow is to utilize turbulence and therefore increase the amount of heat that is being transferred from the fuel pebble, which is undergoing the fission reaction, to the coolant itself. Naturally, various adverse pressure gradients which will become predominant in energized turbulent boundary layers, will also have to be taken into account. This paper will address the effect of boundary layer formation on energy exchange and heat interaction within the core. Moreover, the flow conditions that are designed over the fuel pebbles with grater turbulence will help to improve the energy exchange between the nuclear fuel pebble and the coolant. In this paper, we will demonstrate the added heat ratios with the help of CFD simulations with Helium as the coolant and it will address the effectiveness of energy exchange with the help of boundary layer formation over nuclear spherical fuel pebbles in gas cooled reactors.

From the past many decades, many researches have worked on different airfoils for getting the eff... more From the past many decades, many researches have worked on different airfoils for getting the efficient lift. Lift and drag are the two factors on ehich aerodynamic efficiency is based on. These can be determined by the pressure distibution over the airfoil.. Pressure distribution depends on the free stream velocity of air around the airfoil. At low Reynolds number, velocity of flow of an airfoil is lower then the velocity of flow at high Reynolds number, which is a reason for the decrease in the lift. So, to increase the performance of airfoil at low Reynolds number, there are some methods involved like airfoil shaping, boundary layer control and also by increasing the flow speeds over the blades. In the present work, an airfoil is designed by taking the computational approach and lift variations are studied for the airfoil at low Reynolds numbers. Then the lift variations are again studied at low Reynolds number by involving the above mentioned methods. Viscous flow analysis is us...

Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in th... more Gas cooled Nuclear Reactors with the fuel pebble arrangement will create a great efficiency in the power generation. Helium as a coolant is more effective in exchanging heat between fuel pebbles and the coolant and maintains good advection ratio in the core. However, one of the more important points in nuclear power generation is to increase the heat production rate as much as possible. But, in real life, all nuclear reactors are bound in their maximum efficiency by the Carnot cycle. Hence, the only thing that can be done is to increase the heat transfer gradients in order to help increase the overall efficiency of the heat production system in a nuclear reactor. One of the most effective ways of increasing the heat transfer capacity to a flow is to utilize turbulence and therefore increase the amount of heat that is being transferred from the fuel pebble, which is undergoing the fission reaction, to the coolant itself. Naturally, various adverse pressure gradients which will become...

In the present work, investigation of various turbulence models has been carried out for predicti... more In the present work, investigation of various turbulence models has been carried out for predicting the efficient turbulence model for a two-dimensional nozzle designed for a supersonic cruise nozzle. Initially, a computational domain was created for a two-dimensional nozzle for a supersonic cruise, then, with an appropriate mesh size, various turbulence models has been used for simulations. The main objective of the present work is to determine the efficient turbulence model for nozzle designs. As till date, commercial software's are implementing many advanced technique, the test of turbulence model is very much needed for today's research. The results obtained from the computational approach were compared with experimental approach which was conducted in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.8 to 1.2 by NASA Langley Research Centre, Virginia. These supersonic cruise nozzles have a wide range of applications in designing Fighter jets and supersonic cru...