双腔室自振脉冲喷嘴数值分析与实验研究

Numerical Analysis and Experimental Research of a Dual Chamber Self-excited Oscillation Pulsed Jet Nozzle

基于水声学原理和瞬变流理论,并结合标准的κ-ε模型,以双腔室自振脉冲喷嘴为研究对象,通过改变第二级腔室结构,应用FLUENT软件对该喷嘴进行内外流场数值模拟,得到了打击力最强的腔室结构,并将其与单腔室自振脉冲喷嘴打击力进行对比。研究结果表明,存在最佳腔长、腔径和下游碰撞壁形状时该喷嘴打击力最大且双腔室自振脉冲喷嘴打击力较单腔室大13.2%。构建实验装置进行冲蚀实验,通过分析不同结构的喷嘴对岩石的冲蚀规律以及统计冲蚀体积和深度。结果表明,冲蚀实验的喷嘴最佳结构与数值模拟相一致,与单腔的Helmholtz自激振荡喷嘴相比冲蚀体积和冲蚀深度提高了14.5%和12.6%。

With dual chamber self-excited oscillation pulsed jet nozzle as the research object, changing the structure of the second stage chamber as the variables, the inner and outer flow fields of the jet nozzle were simulated by using FLUENT. These studies are based on the theories of transient flow and underwater acoustics, and combined with the standard κ-ε model. The structural chamber of the strongest hitting power is obtained, and hitting power was compared with self-excited oscillation pulsed jet nozzle. Research results show that the nozzle has the largest hitting power with optimal cavity length, cavity diameter and downstream collision wall shape of the nozzle, and hitting power of self-excited oscillation pulsed jet nozzle is more than the single chamber 13.2%. An experiment was built to make the erosion test, erosion law of rock was analyzed, and erosion volume and depth were computed. The results show that the best structure of the nozzle is in agreement with the numerical simulation; Compared with the single chamber Helmholtz self-excited oscillation pulsed jet nozzle, the erosion volume and depth increased by 14.5% and 12.6%.