波纹形多孔介质腔内纳米流体自然对流数值研究  

Study on Natural Convection of Waviness Porous Medium Intracavity Nanofluids

作　　者：张策 马兵善[1] 王刚[1] Zhang Ce;Ma Bingshan;Wang Gang(School of Civil Engineering,Lanzhou Universit y of Technology,Lanzhou 730050,Chin)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050

出　　处：《甘肃科学学报》2018年第4期87-93,共7页Journal of Gansu Sciences

基　　金：国家科技支撑计划项目(2011BAJ03B08)

摘　　要：采用局部非热平衡模型数值研究了波纹形多孔介质腔体内Cu-水纳米流体的自然对流换热。腔体左侧及右侧波纹曲面的温度分别保持恒定的低温和高温,上、下壁面绝热。在曲线坐标中用有限容积法离散方程,纳米流体的流动采用达西模型来描述。在腔体波峰突起相对高度λ保持定值的情况下,研究了瑞利数Ra、达西数Da、无量纲容积换热系数Nhs及纳米颗粒体积分数φ对腔体内Cu-水纳米流体自然对流换热的影响。计算结果表明:纳米流体相平均努赛尔数Nunf随瑞利数Ra、达西数Da的增加而增加,随无量纲容积换热系数Nhs的增加而减小;低无量纲容积换热系数下,局部非热平衡效应影响明显;纳米流体相平均努赛尔数Nu_(nf)和固体骨架相平均努赛尔数Nus随纳米颗粒体积分数φ的增加而增大。Use local non thermal balance model value to study Cu-water natural convection heat transfer in waviness porous medium cavity.The temperature on left and right waviness curve surface of cavity were kept as constant low and high temperature,the upper and lower wall surface is heat insulation.Use finite volumetric disperse equation to descript in curvilinear coordinates,and nanofluids uses Darcy model to descript.When relative heightλof intracavity wave crest was kept as constant,study the effect of Rayleigh Ra,Darcy Da,dimensionless volume coefficient of heat transfer Nhs and nano particles volume fractionφon Cu-water nanofluids natural-convection heat transfer.The result shows that the average Nusselt Nunfof nanofluids phase increases with Ra and Da increasing,decreases with Nhs increasing;under low dimensionless volume coefficient,local non thermal balance effect is obvious;Nunfof nanofluids and Nusof solid skeleton increases withφincreasing.

关 键 词：多孔介质 纳米流体 自然对流 局部非热平衡 波纹型腔体 

分 类 号：TK124[动力工程及工程热物理—工程热物理]