自激脉冲发生机理数值模拟及参数影响分析

为了揭示低压大流量下自激振荡脉冲射流清洗的脉冲发生机理，研究了这种工况下喷嘴结构和运行
参数的优化设计范围.通过给出一种应用于大型工业油罐罐底油泥清洗的新型喷嘴结构型式，比较了在低
压大流量工况下该喷嘴脉冲的发生机理、表现形式、分析方法与高压小流量情况下存在的差异.用计算流
体力学（CFD）软件对自激振荡腔内压力场进行数值研究，并对影响频率特性的结构和运行参数进行了逐
一分析，获得了喷嘴的结构参数和运行参数的优化配比范围.结果表明，在低压大流量工况下，空化汽囊
的周期性变化是产生脉冲射流的根本原因，得到的优化参数可直接应用于指导低压大流量自激喷嘴的工业
设计.

Numerical simulation of self-exicited oscillation pulsed jet and analysis of parameters' influence

To explain the generative mechanism of low pressure and mass flow self-excited oscillation pulsed jet, the nozzle optimized design range of structure and operation parameters was investigated. By bringing forward a new-style nozzle used in the cleaning of large industrial oil tank bottom sludge, the generative mechanism, appearance shape and analysis method of the nozzle worked in low pressure mass flow were compared with that in high pressure fewness flow. After nozzles' pressure field in the self-excited oscillation cavitations were simulated by compute fluid dynamics (CFD) software, the structure and operation parameters' influences on frequency characteristic were analyzed respectively, and the structure and operation parameters' optimized range were obtained . The results show that the ultimate pulsed jet is caused by the capitation's shape change, and that the optimized parameters' range can be used to direct nozzles' optimized design.