The Study Of Nanofluid In The Soft Nanochannels With Thermal Radiation

With the increase in the requirements of micro/nano-electro-mechanical system(M/NEMS)for heat exchange equipment,nanofluids meet the needs of technical development with its unique thermophysical properties.They have wide research and application prospects because of themselves good thermal conductivity,high heat transfer efficiency,strong stability and are not easy to damage the channel.The soft channels whose wall made or covered by polyelectrolyte materials(PEL)have attracted the attention of scholars.Compared with rigid channels,the streaming potential and electro-viscous effects are significantly different,and the soft channels have the advantage of more efficient conversion of electrochemical mechanical energy.The electrolyte ions can freely exist inside and outside the PEL,while the PEL-ions only present in the PEL.Hence,the PEL-electrolyte interface acts as a semi-permeable membrane.As PEL affects the movement of fluid in the system,it can be used to control the flow of the working fluid.Therefore,the soft channels play a positive role in the intelligent control of micro/nano-channels.Thermal radiation should not be ignored which widely applies in biological science,medical diagnosis and other aspects.Consequently,the flow and heat transfer mechanism of nanofluids in soft channles,especially the effect of thermal radiation,are being closely watched by researchers.Based on the above description,the flow and heat transfer behavior of nanofluids as working fluids through a slit parallel plate soft nanochannel are studied,and the exploration of thermal radiation is strengthened to provide part of theoretical support for the miniaturization of fluid system.Dividing the issue into two circumstances and gives respective discussions,in which one is driven by the pressure gradient,external uniform axial electric field and the other is driven by the pressure gradient,mixed external uniform axial electric field and the vertical magnetic field.Using the electric double layer(EDL)model,the Poisson-Boltzmann equation is solved analytically under the Debye-Hückel linearization due to take low electric potential into account.Subsequently,the velocity and temperature distributions are derived by dealing with the modified Navier-Stokes momentum equation and energy equation without neglecting the effects of viscous dissipation,wall slip,Joule heating,thermal radiation and peculiarly the Hall Effect.Besides,particular attention is paid to the Nusselt number and entropy generation.Representative results estimated on the basis of the pertinent parameters available in the existing literatures are shown with the help of graphs and the effects of different parameters on fluid flow and heat transfer are analyzed.