三角形并联微通道换热特性研究

基于Navier-Stokes方程的传统理论,把整个实验硅晶片上的所有并联微通道纳入计算区域,通过FLUENT商业软件对其进行数值模拟.计算得到的温度场和实验结果的红外成像数据对比,吻合得很好,从而验证了数值计算的正确性.对并联通道中的不同通道计算结果表明,不同微通道中流量几乎没有差异,但是不能完全忽略热流密度的差异.此外,通过三角形微通道在壁面上的热流密度分布很不均匀,与矩形通道截然相反;轴向导热对热流密度的分布有很大影响.在进出口温差较大时,用进出口平均温度作定性温度计算的结果与变物性计算的结果相比,误差很小.

Heat transfer of parallel triangular microchannels

Based on the conventional Navier-Stokes theory,the whole silicon substrate was included as the computation domain and was simulated by the commercial package FLUENT.The numerical result was validated by comparing the calculated temperature field with the experimentally measured one.The results show that there is almost no difference between different microchannels in terms of flow rate.However,the influence of different side-wall heat flux cannot be neglected,especially at higher heat power input.In addition,the side-wall heat flux distribution on triangular microchannels is very uneven in contrast to that on rectangular microchannels,and axial conduction exerts a large impact on heat flux distribution.There is little difference between the result based on constant average temperature and that which is caculated using properties.