矩形带肋通道中脉动流强化换热数值研究

Numerical Study of Heat Transfer Enhancement for Pulsating Flow in Single Duct with Ribs

为了提高燃气轮机叶片内部对流冷却,采用脉动蒸汽流取代稳态蒸汽流作为内冷介质。利用数值计算方法研究脉动蒸汽流在矩形带肋通道中的强化换热能力。通过与稳态蒸汽流的对比,分析了非稳态脉动流的脉动频率、脉动幅值和雷诺数对换热效果的影响。计算结果表明,脉动流对换热的影响取决于流体压力梯度的大小,当脉动的蒸汽处于逆压梯度区间,逆压梯度越大瞬态换热更强。而顺压梯度有稳定流体的作用,在顺压梯度时间区间,有瞬时的换热甚至低于稳态流体冷却的情况出现。

To enhance the internal cooling efficiency of gas turbine vane, the pulsating steam flow^the steady steam flowas the coolant. We study the heat transfer enhancement in ribbed rectangular channel by u-sing the numerical simulation. Through comparison with steady-state steam flow,the influences of pulsating fre-quency, pulsating amplitude and the reynolds number of unsteady state steam flow^ on heat traThe results show that ; the heat transfer is greatly affected by the pressure gradient of tlie flow^ ; in the adverse pres-sure gradient section,the greater tlie adverse pressure gradient,the stronger tlie transient heat travorable pressure gradient can make the flow stable and reduce the heat transfer rate.