关键词: 水气多相流, 空隙率波, 测量, 传播, 流态转化

Abstract: Gas-liquid two phase flow experiments were conducted in a vertical pipe whose diameter is 112.5mm, and length is 12m. Void fraction waves were measured by impedance void fraction meters and analyzed. The results show that the liquid superficial velocity and the pipe diameter are two main factors to affect the evolution of the flow regime and the characteristics of void fraction wave. The critical void fraction of bubbly flow losing its stability becomes lower with the liquid superficial velocity goes high. The propagating velocity value of void fraction wave is higher in big diameter pipe than that of small diameter pipe. Analyzing results show that the turbulivity plays an important role in the process of flow regime evolution. The analysis on void fraction waves shows that the curves of PDF and amplitude spectrum in different regimes are different, and the frequencies of void fraction waves become single with increasing of void fraction.

Key words: gas-water two-phase flow, void fraction wave, measurement, propagation, flow regime transition