脉动流动强化换热的数值研究

对脉动流动强化凸块散热进行了数值研究,讨论了雷诺数Re,斯德鲁哈尔数St,脉动振幅A等参数对凸块散热性能和通道中压力损失的影响。数值结果表明,脉动流动加强了流体的扰动和掺混作用,增强了流体的传热能力,进而强化了凸块的散热。凸块散热的强化效果随着Re数和A的增大而增大,并且对于该模型存在最佳的St数。另外,通道中瞬时压力损失满足正弦规律变化,其周期平均的压力损失与稳态时差异不大。

NUMERICAL STUDY OF ENHANCING HEAT TRANSFER BY PULSATING FLOW

A numerical study is presented for the enhancement of heat transfer from the not blocks by pulsating flow. Comprehensive studies are carried out to investigate the influence of several parameters, including Renolds number based on the mean flow, Re, Strouhal number, St, pulsation amplitude, A, et al. The results obtained indicate that the flow disturbance and mixing are enhanced due to the flow pulsation, which leads to the enhancement of heat exchange between the hot fluid and the cool fluid in the grooved channel and the augmentation of heat dissipation from the hot blocks. The enhancement of heat dissipation from the blocks is increased with the increase in Re and A, and there exists an optimal Strouhal number for this model. The results also show that the transient pressure drop varies sinusoidally, but periodic averaged pressure drop is close to the steady case.