制冷技术

针对晃荡复杂工况下二级分配歧管内液体喷淋分布不均的问题，本文通过数值模拟研究了几何参数与晃荡工况对流动分布均匀性的影响机制。研究引入一级面积比（AR1，主管与支管截面积之比）和二级面积比（AR2，支管与喷孔截面积之比）作为关键设计变量，结合均匀性指数对分配性能进行量化评价。结果表明：歧管内流动受压力梯度主导，分配均匀性由AR1与AR2共同约束，通过两级面积比协同可使得均匀性指数从0.916 2升至0.988 3，在横荡、纵荡和垂荡等晃荡工况下，因体积力不占主导，对均匀性影响较小，甚至会改善局部涡流导致的分配不均；而周期性横摇产生的瞬时惯性力具有时均抵消效应，对时均的均匀性影响有限，但较粗支管会增强流动不稳定性。

To address the uneven spray distribution in a two-stage distribution manifold under complex sloshing conditions, a numerical simulation study is conducted to investigate the influence mechanism of geometric parameters and sloshing conditions on flow distribution uniformity. The primary area ratio(AR1, the cross-sectional area ratio of the main pipe to the branch pipes) and the secondary area ratio(AR2, the cross-sectional area ratio of the branch pipes to the spray holes) is introduced as key design variables in this paper. The distribution performance was quantitatively evaluated using the uniformity index. The results indicate that the flow inside the manifold is dominated by the pressure gradient, and distribution uniformity is jointly constrained by AR1 and AR2. Through synergistic coordination of the two-level area ratios, the uniformity index was improved from 0.916 2 to 0.988 3. Under sloshing conditions such as sway, surge, and heave, the body forces do not dominate the flow; therefore, their impact on uniformity is limited, and in some cases, the sloshing may even mitigate local maldistribution caused by vortex flows. The transient inertial forces induced by periodic rolling exhibit a time-averaged canceling effect, leading to a negligible influence on the time-averaged uniformity, although thicker branch pipes were observed to amplify flow instability.