In this research,the three-dimensional(3D)steady and incompressible laminar Homann stagnation point nanofluid flow over a porous moving surface is addressed.The disturbance in the porous medium has been characterized ...In this research,the three-dimensional(3D)steady and incompressible laminar Homann stagnation point nanofluid flow over a porous moving surface is addressed.The disturbance in the porous medium has been characterized by the Darcy-Forchheimer relation.The slip for viscous fluid is considered.The energy equation is organized in view of radiative heat flux which plays an important role in the heat transfer rate.The governing flow expressions are first altered into first-order ordinary ones and then solved numerically by the shooting method.Dual solutions are obtained for the velocity,skin friction coefficient,temperature,and Nusselt number subject to sundry flow parameters,magnetic parameter,Darcy-Forchheimer number,thermal radiation parameter,suction parameter,and dimensionless slip parameter.In this research,the main consideration is given to the engineering interest like skin friction coefficient(velocity gradient or surface drag force)and Nusselt number(temperature gradient or heat transfer rate)and discussed numerically through tables.In conclusion,it is noticed from the stability results that the upper branch solution(UBS)is more reliable and physically stable than the lower branch solution(LBS).展开更多
The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of the...The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of thermodynamics is used to define whether the given system is reversible or irreversible.Here,our focus is how to reduce the entropy of the system and maximize the capability of the system.There are many methods for maximizing the capacity of heat transport.The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy.The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel.For this,we choose two different fluid models,namely,the plane and generalized Couette flows.The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid.The present analysis shows the effects of the fluid parameters on the velocity,the temperature,the entropy generation,and the Bejan number.The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method.To validate the perturbation solution,a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0.The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters.It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number.Whenηi→0(i=1,2,3),the Eyring-Powell fluid is transformed into a Newtonian fluid.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.11971142,11871202,61673169,11701176,11626101,and 11601485)。
文摘In this research,the three-dimensional(3D)steady and incompressible laminar Homann stagnation point nanofluid flow over a porous moving surface is addressed.The disturbance in the porous medium has been characterized by the Darcy-Forchheimer relation.The slip for viscous fluid is considered.The energy equation is organized in view of radiative heat flux which plays an important role in the heat transfer rate.The governing flow expressions are first altered into first-order ordinary ones and then solved numerically by the shooting method.Dual solutions are obtained for the velocity,skin friction coefficient,temperature,and Nusselt number subject to sundry flow parameters,magnetic parameter,Darcy-Forchheimer number,thermal radiation parameter,suction parameter,and dimensionless slip parameter.In this research,the main consideration is given to the engineering interest like skin friction coefficient(velocity gradient or surface drag force)and Nusselt number(temperature gradient or heat transfer rate)and discussed numerically through tables.In conclusion,it is noticed from the stability results that the upper branch solution(UBS)is more reliable and physically stable than the lower branch solution(LBS).
基金Project supported by the National Natural Science Foundation of China(Nos.11971142,11871202,61673169,11701176,11626101,and 11601485)。
文摘The unavailability of wasted energy due to the irreversibility in the process is called the entropy generation.An irreversible process is a process in which the entropy of the system is increased.The second law of thermodynamics is used to define whether the given system is reversible or irreversible.Here,our focus is how to reduce the entropy of the system and maximize the capability of the system.There are many methods for maximizing the capacity of heat transport.The constant pressure gradient or motion of the wall can be used to increase the heat transfer rate and minimize the entropy.The objective of this study is to analyze the heat and mass transfer of an Eyring-Powell fluid in a porous channel.For this,we choose two different fluid models,namely,the plane and generalized Couette flows.The flow is generated in the channel due to a pressure gradient or with the moving of the upper lid.The present analysis shows the effects of the fluid parameters on the velocity,the temperature,the entropy generation,and the Bejan number.The nonlinear boundary value problem of the flow problem is solved with the help of the regular perturbation method.To validate the perturbation solution,a numerical solution is also obtained with the help of the built-in command NDSolve of MATHEMATICA 11.0.The velocity profile shows the shear thickening behavior via first-order Eyring-Powell parameters.It is also observed that the profile of the Bejan number has a decreasing trend against the Brinkman number.Whenηi→0(i=1,2,3),the Eyring-Powell fluid is transformed into a Newtonian fluid.
