SIMULATION ON FLOW PATTERNS AND CHARACTERISTICS OF TWO-PHASE GAS-LIQUID FLOW IN A 90° BEND UNDER DIFFERENT GRAVITY

The flow patterns and characteristics of two-phase gas-liquid flow in a 90° bend under different gravity were simulated. Based on the VOF (Volume of Fluid) method, a three-dimensional mathematical model of two-phase gas-liquid flow in a 90° bend tube was established to analyze the distribution of flow pattern, the cross-sectional void fraction, the slip ratio and the maximum skew angle in tail of the gas phase in a 90° bend under varied gravities of 10^-6g₀, 10^-4g₀, 10^-2g₀ and 1g₀ (g₀ = 9.8m/s²). It is shown that the effects of flow patterns and cross-section void fraction of gas-liquid two-phase flow under varied gravity conditions can be correctly analyzed by the developed model and the difference of secondary flow is obtained between the gas-liquid two-phase bend flow and the single-phase flow. With the increasing of gravity level, that the gas phase is accumulated to the inside of the 90° bend makes the effect of 90° bend on the gas phase flow and the oblique effect the 90° bend to the tail get weaken.