Abstract: In this paper, an experiment is conducted to investigate the effects of oscillation on transient and time average heat transfer characteristics for fully developed turbulent flow in a uniformly heated helical coiled tube. The phase lag of transient coefficient of local heat transfer relative to the phase feature of flow rate oscillations is also studied. The experimental range of parameters is as follows: Re=25000～125000, oscillations frequency f=0.05～0.003, which corresponds to the thermal hydrodynamic oscillations encountered in a helical coiled tube boiling channel. A correlation for predicting the time-averaged heat transfer coefficient of single-phase turbulent flow under unsteady or oscillatory condition is proposed. The secondary flow mechanisms and the effects of interaction between the flow rate oscillation and secondary flow are analyzed on the basis of experimented data. Some new phenomena are observed and explained.

摘要： 以水为工质对螺旋管内单相液体充分发展紊流脉动传热特性进行了实验研究 ,发现了紊流脉动传热系数与流量脉动相位间的反相关系 ,引进了两个新的准则数 :脉动频率数W0 和脉动振幅率Ap,对紊流脉动传热规律进行了分析讨论 ,并根据紊流脉动传热参数的瞬态变化规律 ,对脉动过程中的管内二次流特征和变化作了详细讨论和分析 .