金属多孔介质泡沫自然对流换热实验研究

摘要

本文对饱和水-泡沫铜多孔介质在方腔内的自然对流换热进行了实验研究.讨论了孔隙率、孔隙密度及倾斜角度对多孔介质自然对流换热的影响.结果表明:自然对流换热随着孔隙率增大而减小.当孔隙率一定时,随着孔隙密度的增大,自然对流换热减小.Nu数随着加热功率的增大而增大,随着腔体倾斜角度的增大而减小.根据相似理论建立了以孔隙率、孔隙密度、倾斜角度为影响变量的换热准则关联式,且误差小于±7.5％.%Natural convection heat transfer is experimentally investigated for a porous medium,water-saturated copper foam,in a square cavity.The effects of porosity,pore density (PPI) and angle of inclination on natural convection heat transfer are discussed.The experi mental results show that natural convection heat transfer rate increases with the decrease of porosity.For a given porosity,the heat transfer rate is found to be lower at higher pore densities.The Nusselt number decreases with the angle of inclination.According to the theory of similarity,the dimensionless heat transfer correlation,including porosity,pore density (PPI) and angle of inclination,is developed,and deviation is within ±7.5％.