脉冲防暴水炮非淹没气体射流的RANS和LES模拟

为提高脉冲防暴水炮刺激剂的雾化水平,必须提高射流的出口速度和改善雾化带形状,而这些因素与管内非淹没气体射流的湍流流场息息相关。为准确描述湍流分布和水柱加速过程,对脉冲防暴水炮的非淹没气体射流进行了RANS和LES模拟。结果表示LES模型较RANS的标准k-ε模型能更为精确地描述湍流分布和管内非淹没气体射流速度的各向异性。但两者对于水柱加速过程的描述基本一致,只是由于LES模型的气液参混较为充分,气液速度相差较小,而可能导致两模型气体在喷口膨胀规律的异同。LES模型气液界面复杂,是用于研究管内气液流型的理想方法。该方法为三维模拟打下了较好的基础,所得结果可以作为管外射流研究的初始条件。

RANS and LES Simulation of Non-submersed Gas Flow of Pulsed Anti-riots Water Cannon

In order to improve the atomization effect of irritant of pulsed anti-riots water cannon,the exit velocity of jet should be increased and the shape of the atomization agglomerate should be meliorated, and both of them have connection with non- submersed gas flow’ s turbulence flow-field.In order to describe the turbulence distribution and the velocity increase process exactly,the RANS and LES simulation was done to the non-submersed gas flow of pulsed anti-riots water cannon.The results show that LES model can describe the turbulence distribution and velocity’s anisotropy of non-submersed gas flow more accurately than RANS’ standard k-εmodel.But both model have consistent describe to the velocity increase process of water column.in LES model,gas-liquid mix more completely,the velocity of gas flow and water is not six to one,so the gas expand rule of both model may be different.The gas-liquid interface of LES model is complicated,so it is a good method to study the gas-liquid pattern.This paper ground the foundation for 3-D simulation,and the results can be the initialize condition to the study of outside jet.