摘要
针对不同的边界条件 ,分析了微矩形槽道内不可压缩性气体在速度滑移和温度跳跃区的流动和换热过程 .在分析模型中 ,假定矩形槽道底面定热流加热 ,其余 3个面绝热 .分别在一阶、二阶滑移及速度滑移和温度跳跃相互耦合的边界条件下给出了截面上速度和温度分布的数值解 ,讨论了阻力和换热特性 ,并与Arkilic等的实验结果进行了比较 .结果表明 :在相同的条件下 ,耦合的阻力系数最小 ,二阶边界次之 ,一阶边界最大 ;速度滑移和温度跳跃对换热系数具有相反的影响趋势 ;耦合模型更接近实验结果 ,其次为二阶滑移模型 ,一阶滑移模型的偏差最大 ;在不考虑可压缩性因素时 ,滑移边界条件的阶数对阻力系数的影响较大 ,对换热系数的影响不是十分明显 .
Under different boundary conditions, theoretical analysis is made for gas flow and heat transfer in micro rectangular channels where velocity-slip and temperature-jump prevail. The models are based on the assumptions that the bottom wall of the channel is in a state of uniform heat flux while the other three walls are adiabatic. Numerical solutions are obtained for both the velocity and temperature under the boundary conditions of first order slip, second order slip and coupling between velocity-slip and temperature-jump. The friction and heat transfer performance are discussed and compared with the experiment data by Arkilic et al. Under the same conditions, the friction coefficient of the coupled boundary model is always less than that of both first order slip model and second order slip model such that the first order slip model yields the largest result. In these three models, the coupling model fits the experiment data best. This is followed by the second order slip model and then the first order slip model. Velocity-slip and temperature-jump impact on the Nusselt number takes place in an adverse way. The order of slip boundary condition shows an apparent influence on the friction coefficient but only a slight influence on the Nusselt number if compressibility is ignored.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2001年第10期1067-1071,共5页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金"九五"重大资助项目 (5 9995 5 5 0 - 3)
