倾斜条件下强迫流动的传热特性研究

对倾斜条件下圆管内强迫流动的传热特性进行实验研究及数值分析。实验结果表明,对于单相流动,在浮力的作用下圆管内的传热呈现非对称状态;圆管上侧传热减弱,壁温升高,而圆管下侧传热增强,壁温降低。数值模拟的结果也是如此。以此为基础,提出引入倾斜条件下传热的修正因子,可以较好地预测倾斜条件下单相对流传热的变化幅度。对两相流动中的汽泡进行受力分析,揭示倾斜条件对两相传热影响不大的原因。

Heat Transfer Characteristics of Forced Circulation under Inclined Conditions

Experimental researches and numerical analysis on the heat transfer characteristics of forced circulation flow in a circular tube under different inclined conditions were introduced in this paper.For the single-phase flow,the experimental results show that the heat transfer around the tube was unsymmetrical under the buoyancy effect,and the heat transfer was weakened at the upside of tube to increase the wall tem-perature,while the heat transfer was enhanced at downside to decrease the wall temperature.The numerical calculation results show the same phenomena.Based on the experiment,a modified factor for the inclined heat transfer coefficient was presented in this paper,to estimate more accurately the heat transfer variation in single phase convection at inclined condition..Stresses on the bubble in two-phase flow was analyzed,to il-lustrate the why the effect of inclined condition on the heat transfer is not obvious.