不同振动参数下脉动气流横掠圆柱体的传热研究

摘要

在脉动气流强化传热实验台上进行了层流（雷诺数RP为171）中不同振动参数（频率厂分别为15Hz、30Hz、45Hz、59Hz，振幅Pmax为45～286Pa）下脉动气流横掠高温共烧陶瓷发热管的传热实验研究．结果表明：层流中低频大振幅的脉动气流能显著强化圆柱体的传热过程，相对努塞尔数随着压力振幅的增大而增大，随着脉动频率的增大而减小，最大相对努塞尔数N“，可超过2．55；在Re=171时，脉动气流强化传热的经验公式为Nux=0．2684＋0．5867pmax^0.388.3/f^0.3170，该经验公式的相关系数为R=0．9941，揭示了脉动气流强化圆柱体传热过程对振动参数的非线性依赖性．%To study the influence of vibration parameters on heat transfer over a cylinder with uniform heat flux in laminar pulsating airflows, an experimental study was carried out on a test rig, with a Reynolds number of 171, under conditions of f=15, 30, 45, 59 Hz, pms=45-286 Pa. Results show that the heat transfer can be enhanced obviously in pulsating airflows with low pulsating frequency and large pressure amplitude. The relative Nusselt number increases with rising pressure amplitude and reducing pulsating frequency, which may get up to 2.55. In the case of Re= 171, the empirical formula for heat transfer en- hancement isNux=0.2684＋0.5867pmax^0.388.3/f^0.3170, with the correlation coefficient R = 0. 994 1, indicating a nonlinear relationship between the vibration parameters and heat transfer enhancement.