K.P.V.KRISHNA VARMA MECH-ASSISTANT PROFESSOR - Academia.edu (original) (raw)

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Papers by K.P.V.KRISHNA VARMA MECH-ASSISTANT PROFESSOR

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

The new generation vehicles are designed with feasible engineering techniques by reducing their e... more The new generation vehicles are designed with feasible engineering techniques by reducing their engine sizes and making them more power full and to maintain European standards thus by reduced engine there is an reduced power so the engines are equipped with the forced induction systems like turbo chargers and super chargers thus as an complete manually working turbo chargers gona work completely on a electric motor thus the turbo lags will be reduced drastically and doesn’t give any load to the engine thus our electric turbo works on the principle the electric motor fixed to the end of a impeller and as the motor runs their will a movement in the impeller and it starts blowing the air inside the combustion chamber. The rate of acceleration is equal to the power given to motor by a service battery. The main components of the Electronic powered turbo are inside air flow assembly DC motor, potentiometer, DC driver, and a set of wiring harness.

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

International Journal of Mechanical and Production Engineering Research and Development , 2019

There are many aspects of the current day technology where the structures are subjected to many k... more There are many aspects of the current day technology where the structures are subjected to many kinds of loads. Some of them are wind loads, and some of them are static loads, static loads occur when the physical load like weight or force applied in many cases like beams and structures. But the wind loads occur as the object is resting at the location and the wind is flowing around it. In this paper, such kind of condition taken for the solar panel and the solar farm where the single panel array subjected to higher and lower velocities of wind speeds. In this project, a solar panel array mounted at the ground plane is subject to wind speeds for 5mls and 25 m/s to investigate pressure effect on each panel in the array where the panel is placed at 180 to ground plane and 720 to the latitude. The design and simulation of this problem are done using commercial CFD package fluent, a subsidiary of Ansys Inc. The work presented in the paper is done using simulation concepts of computational fluid dynamics. This work helps in getting the overview and optimization of the necessary parts and areas that are affecting by the wind, which can predict the dislocations of the solar panels.

International Journal of Mechanical and Production Engineering Research and Development , 2019

Present work reports on analysis of effect of wall functions in a STHE on surface heat transfer. ... more Present work reports on analysis of effect of wall functions in a STHE on surface heat transfer. The inlet temperature of hot fluid, which is flowing in a pipe, is maintained at 333Kand inlet of cold fluid, flowing in shell is maintained at of 300K. The tube wall is conductive medium and is made of stainless steel, where shell tube is considered as a pure insulator. Water is considered as working fluid for this study. HTC of wall is considered as the variable of interest to analyze enhanced wall function and K-e standard wall function. Using enhanced wall treatment function, the velocity distribution and the temperature distribution near the wall regions for laminar sub layer are captured clearly, which is otherwise not possible with the standard wall function.

University College of Engineering Kakinada(A) JNTUK Kakinada A.P. India, 2016

A numerical simulation was performed to study the heat transfer performance of a hot fluid in a c... more A numerical simulation was performed to study the heat transfer performance of a hot fluid in a confined impinging jet on a flat heated surface. The tests were realized for the following ranges of the governing parameters: the jet thickness is 2m and the distance of horizontal jet to heated surface was set to 1 to 3 cm. Three different cases are considered in this analysis. They are H/D = 0.5,1. Fluids like Acetylene are compared with ?-Al2O3nan o fluid in this analysis. Tu rbulent models considered for this analysis are k-? and k-?. Out of these two k-? model gives more heat transfer characteristics. The plate is considered to be stationery. Horizontal Jet with convergent nozzle is considered and compared in this analysis. Finally it is found that surface nusselt number and surface heat transfer coefficient plays vital role for better heat transfer

Anurag Group of Institutions, 2019

Computational fluid dynamics became one of the most popular tool to solve robust problems in Scie... more Computational fluid dynamics became one of the most popular tool to solve robust problems in Science and Research field. Problems from heat transfer in a heat exchanger to aero dynamics of jets can be solved numerically with sensible accuracy. This study focuses on one such problem in powder coating technology where the powder particle transfer efficiency is the driven parameter. The powder is coated on a coating surface by accelerating velocity of air which triggers in mixing and drawing powder particles along with it. In this simulation a 2phase (gas and solid) DPM (discrete phase modeling) is used to analyses the flow and study the particle trajectories. This study shows how the coating layer thickness and particle transfer efficiency behaves with varying input parameters like velocity of gas and particles, diameter.

Innovare Academics Sciences Pvt. Ltd, 2021

For proper combustion, bowl in the piston geometry plays a crutial role when the engine valves ar... more For proper combustion, bowl in the piston geometry plays a crutial role when the engine valves are in closed position. In the present work, the combustion geometry is of hemi-spherical groove in the upper region of the piston.Simulations weres conducted for different blends(B20+Al40, B20+Al80) to analyze the combustion features in a four stroke diesel engine using ANSYS R18.1 software considering above geometry of the piston.. Pertaining to greater amount of density, viscosity of biodiesel blends, variations for B20+Al80 render more performance than the biodiesel. Turbulent kinetic energy of both the fuels follow similar trend due to proper mixing of air with the fuel from fuel injector.

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

The new generation vehicles are designed with feasible engineering techniques by reducing their e... more The new generation vehicles are designed with feasible engineering techniques by reducing their engine sizes and making them more power full and to maintain European standards thus by reduced engine there is an reduced power so the engines are equipped with the forced induction systems like turbo chargers and super chargers thus as an complete manually working turbo chargers gona work completely on a electric motor thus the turbo lags will be reduced drastically and doesn’t give any load to the engine thus our electric turbo works on the principle the electric motor fixed to the end of a impeller and as the motor runs their will a movement in the impeller and it starts blowing the air inside the combustion chamber. The rate of acceleration is equal to the power given to motor by a service battery. The main components of the Electronic powered turbo are inside air flow assembly DC motor, potentiometer, DC driver, and a set of wiring harness.

An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid.... more An attempt is made to enhance the rate of heat transfer in heat exchangers using Fe3O4 nanofluid. In this work an experimental analysis on twisted tape inserts with varying cutradius in Hair pin heat exchanger using Fe3O4 water based nanofluid is presented. Experimental data is generated at the mass flow rates of ranging from 0.05Kg/s to 0.25Kg/s and the Reynolds number ranging between 3000 to 25000.where as the flow rate of the hot fluid in the annulus is maintained constant (0.1Kg/s). The Heat transfer coefficient and corresponding friction factors required for performance analysis are determined for various particle volume concentrations of 0.01% and 0.03%. The Nusselt number of entire pipe for 0.03% concentrations of nanofluid with radius of cut, r=6 insert of H/D=3 is enhanced by 32.01% as compared water. The friction factor of entire pipe for 0.03% concentration of nanofluid with radius of cut, r=6 twisted tape insert of H/D=3 is enhanced by 1.21 times as compared to water. Th...

International Journal of Mechanical and Production Engineering Research and Development , 2019

There are many aspects of the current day technology where the structures are subjected to many k... more There are many aspects of the current day technology where the structures are subjected to many kinds of loads. Some of them are wind loads, and some of them are static loads, static loads occur when the physical load like weight or force applied in many cases like beams and structures. But the wind loads occur as the object is resting at the location and the wind is flowing around it. In this paper, such kind of condition taken for the solar panel and the solar farm where the single panel array subjected to higher and lower velocities of wind speeds. In this project, a solar panel array mounted at the ground plane is subject to wind speeds for 5mls and 25 m/s to investigate pressure effect on each panel in the array where the panel is placed at 180 to ground plane and 720 to the latitude. The design and simulation of this problem are done using commercial CFD package fluent, a subsidiary of Ansys Inc. The work presented in the paper is done using simulation concepts of computational fluid dynamics. This work helps in getting the overview and optimization of the necessary parts and areas that are affecting by the wind, which can predict the dislocations of the solar panels.

International Journal of Mechanical and Production Engineering Research and Development , 2019

Present work reports on analysis of effect of wall functions in a STHE on surface heat transfer. ... more Present work reports on analysis of effect of wall functions in a STHE on surface heat transfer. The inlet temperature of hot fluid, which is flowing in a pipe, is maintained at 333Kand inlet of cold fluid, flowing in shell is maintained at of 300K. The tube wall is conductive medium and is made of stainless steel, where shell tube is considered as a pure insulator. Water is considered as working fluid for this study. HTC of wall is considered as the variable of interest to analyze enhanced wall function and K-e standard wall function. Using enhanced wall treatment function, the velocity distribution and the temperature distribution near the wall regions for laminar sub layer are captured clearly, which is otherwise not possible with the standard wall function.

University College of Engineering Kakinada(A) JNTUK Kakinada A.P. India, 2016

A numerical simulation was performed to study the heat transfer performance of a hot fluid in a c... more A numerical simulation was performed to study the heat transfer performance of a hot fluid in a confined impinging jet on a flat heated surface. The tests were realized for the following ranges of the governing parameters: the jet thickness is 2m and the distance of horizontal jet to heated surface was set to 1 to 3 cm. Three different cases are considered in this analysis. They are H/D = 0.5,1. Fluids like Acetylene are compared with ?-Al2O3nan o fluid in this analysis. Tu rbulent models considered for this analysis are k-? and k-?. Out of these two k-? model gives more heat transfer characteristics. The plate is considered to be stationery. Horizontal Jet with convergent nozzle is considered and compared in this analysis. Finally it is found that surface nusselt number and surface heat transfer coefficient plays vital role for better heat transfer

Anurag Group of Institutions, 2019

Computational fluid dynamics became one of the most popular tool to solve robust problems in Scie... more Computational fluid dynamics became one of the most popular tool to solve robust problems in Science and Research field. Problems from heat transfer in a heat exchanger to aero dynamics of jets can be solved numerically with sensible accuracy. This study focuses on one such problem in powder coating technology where the powder particle transfer efficiency is the driven parameter. The powder is coated on a coating surface by accelerating velocity of air which triggers in mixing and drawing powder particles along with it. In this simulation a 2phase (gas and solid) DPM (discrete phase modeling) is used to analyses the flow and study the particle trajectories. This study shows how the coating layer thickness and particle transfer efficiency behaves with varying input parameters like velocity of gas and particles, diameter.

Innovare Academics Sciences Pvt. Ltd, 2021

For proper combustion, bowl in the piston geometry plays a crutial role when the engine valves ar... more For proper combustion, bowl in the piston geometry plays a crutial role when the engine valves are in closed position. In the present work, the combustion geometry is of hemi-spherical groove in the upper region of the piston.Simulations weres conducted for different blends(B20+Al40, B20+Al80) to analyze the combustion features in a four stroke diesel engine using ANSYS R18.1 software considering above geometry of the piston.. Pertaining to greater amount of density, viscosity of biodiesel blends, variations for B20+Al80 render more performance than the biodiesel. Turbulent kinetic energy of both the fuels follow similar trend due to proper mixing of air with the fuel from fuel injector.