中文摘要：

对微圆管进口区运用一阶速度滑移和温度跳跃边界，考察了Kn、动量调和及热调和系数对流动与换热特性的影响机理和规律。模拟结果表明：流动进口段长度随Kn增加而增加，但随动量调和系数减小而减小；热进口段长度随Kn增加而增加，但随动量调和系数及热调和系数减小而减小；Nu数随Kn增加及热调和系数减小而减小，但随动量调和系数减小而增加。

英文摘要：

First order slip velocity and jump temperature boundary conditions are employed to deter- mine the developing flow and heat transfer in the entrance region of a microtube. The influences of the Knudsen number, the momentum accommodation coefficient and the thermal accommodation coeffi- cient are investigated numerically. The results show that the flow developing length increases with the Knudsen number while decreases with the momentum accommodation coefficient; the thermal devel- oping length increases with the Knudsen number while decreases with the momentum accommodation coefficient and the thermal accommodation coefficient; the Nusselt number decreases with the increase in Knudsen number and the thermal accommodation coefficient while increases with the decrease in the momentum accommodation coefficient.