Numerical Simulation Of Convective Heat Transfer In Wavy Channels Enhanced By Electric Field

Enhanced heat transfer is an important subject in engineering research and industry,and it has always been a hot spot for researchers.The electric field enhanced heat transfer technology based on the EHD is an active enhanced heat transfer technology that uses electric field to generate electric field force.The mechanism of EHD’s enhanced heat transfer is attributed to the phenomenon of ion wind from the emitter electrode to the ground electrode,has the advantages of no noise,low energy consumption,and rapid response,so it has received extensive attention and in-depth research.In this paper,a numerical model of convective heat transfer in EHD enhanced wavy channel is established by combining the active heat transfer technology with the passive heat transfer method of wavy channel.A comprehensive study is carried out from several aspects,such as electrode placement,electrode number,geometric parameters of the channel,and grounding mode,to improving the convective heat transfer performance of wavy channel.In the research of the electrode arrangement,it is found that the best electrode position corresponding to different wavy channels is different.The closer the electrode to the entrance,the lower the temperature of the vortex formed,and the higher the ER.As the number of electrodes increases,the distance between two adjacent electrodes decreases,which is likely to produce a barrier effect,so the electrode spacing should be appropriately increased.Finally,a universally meaningful electrode arrangement rule in the wavy channel is obtained.On the other hand,ER first increases with the increase of the number of electrodes,and reaches the maximum value of 7.26 when the number of electrodes is 3.If the number of electrodes continues to increase,ER will decrease instead and the power consumption will increase.In the optimization study of geometric parameters,it is found that as the amplitude-wavelength ratio increases,ER first increases and then decreases,and reaches the maximum value when the amplitude-wavelength ratio is 0.2.Changing the corrugated shape will directly affect the strength and distribution of the electric field force,and the electric field force will directly affect the strength of the vortex,resulting in the difference in the heat transfer performance.In the range of Reynolds number studied in this paper,the heat transfer performance is:sine wavy channel>triangular wavy channel>trapezoidal wavy channel.The coefficient of performance COP can be used to measure the energy efficiency of the EHD.In the study of the grounding mode,it is found that as the length of the ground electrode decreases,the COP value increases.Compared with all grounding,the COP is increased by 7.85%when the continuous wavy channel adopts the 1/4 ground mode,and the COP is increased by 15.82%when the discontinuous wavy channel adopts the 1/4 ground mode.