三面加热窄矩形通道内弹状流截面含气率的实验研究

Experimental Investigation on Void Fraction of Slug Flow in Three-side Heated Narrow Rectangular Channel

本文以去离子水为实验介质,对截面为3 mm×43 mm的三面加热窄矩形通道内充分发展的弹状流进行实验研究。借助高速摄影仪对弹状流进行可视化实验观察,观察到弹状流的4种演变行为:弹状流充分发展、夹心型弹状流的形成、小汽弹合并成大汽弹、大汽弹合并成加长型弹状流。分析了部分热工参数对弹状流截面含气率的影响,通过引入雷诺数,对三面加热窄矩形通道内弹状流的实验数据进行非线性回归分析,得到适用于三面加热窄矩形通道内弹状流截面含气率的计算关系式。结果表明,新拟合得到的关系式能较准确地预测三面加热窄矩形通道内弹状流的截面含气率,其预测值相对误差为12.36%。

The fully developed slug flow in a three-side heated narrow rectangular channel with a 3 mm×43 mm cross section was experimentally investigated by using deionized water as experimental medium in this paper.The visualization experiment of slug flow was carried out by using high speed camera.Four evolution behaviors of the slug flow were observed,which were the full development of slug flow,the appearance of sandwich-type slug flow,the behaviors of merging small slug into large slug and the behaviors of merging large slug into elongated slug.Effect of some thermal parameters on void fraction of the slug flow was analyzed.By introducing the Reynolds number,empirical correlation of void fraction of the slug flow suitable for the three-side heated narrow rectangular channel was obtained by nonlinear regression analysis for experimental data of slug flow.The results show that the new empirical correlation can accurately predict void fraction of slug flow in the three-side heated narrow rectangular channel.The relative error of predicting value is 12.36%.