Simulation Of Boiling Heat Transfer On Microgroove Structure Surface By Lattice Boltzmann Method

As heat exchange requirements continue to increase,heat exchange equipment has become miniaturized and efficient.This makes the research of boiling heat transfer process on microstructure surfaces attract wide attention.In recent years,the lattice Boltzmann method has shown great advantages in the study of microscale problems.Therefore,in this paper,the one component multiphase thermal lattice Boltzmann method is used to calculate the boiling heat transfer process on the microgroove surface.this method is based on the coupling of the pseudo-potential model and the finite difference method.And in this paper,the temperature model is optimized to eliminate the effect of pressure fluctuations on the temperature at the vapor-liquid interface.Next,the boiling heat transfer on the surface of the micro-groove with three wall inclination angles was analyzed.The results show that microgrooves are conducive to the formation of vaporized cores and increase the frequency of bubble detachment.The inclination of the wall of the micro-groove has a great influence on the generation,growth and detachment of the bubbles.First,the motion of bubbles in a single micro-groove was studied.At low superheat,the smaller the inclination of the wall surface,the higher the bubble detachment frequency and the smaller the bubble detachment diameter.Next,the effect of wall contact angle on bubble dynamics at low superheat is analyzed,and it is found that the contact angle has a smaller effect on bubble dynamics than the wall inclination,but this effect will increase as the wall inclination increases.The effects of micro-groove spacing and wall superheat on bubble dynamics in micro-groove groups with three wall inclination angles were also studied.The above factors will have a greater impact on the boiling curve.Different wall inclination angles have a great impact on the heat transfer effect in the transition boiling zone.The micro-groove group with a wall inclination angle of 120° has a larger critical heat flux density and a transition boiling zone.Wall wettability mainly affects the starting point of boiling at low heat flux and the change of heat flux in the transition boiling region.The size of the micro-groove only affects the critical heat flux.