气液联合式碎石器建模与仿真分析

气穴是流体机械中常见的一种有害现象。针对气液联合式碎石器中出现的气穴现象以及目前使用的仿真模型均未考虑内油道形状与对应液阻,在分析主运动件及内流道数学模型的基础上搭建了包含局部阻尼损失的整机仿真模型,根据影响气穴的参数类型及对应取值范围设计了正交试验方案,在此基础上进行了仿真分析。结果显示:活塞运动周期基本不受因子及对应水平组合的影响;活塞质量及氮气室初始容积是影响活塞后腔最低压力及冲程最大速度的主要因子,同时后腔最低压力及最大速度均与活塞质量及氮气室初始容积呈负相关;由于回弹力作用,活塞打击钎杆后并未作停顿而是立即加速回程。

Modeling and Simulation Analysis of Gas-liquid Combined Lithotripter

Cavitation is a common detrimental phenomenon in fluid machinery. Aiming at the cavitation phenomenon in the gas-liquid combined lithotripter and the current simulation model that does not consider the shape of the internal oil channel and the corresponding hydraulic resistance, based on the analysis of the mathematical model of the main moving part and the internal flow channel, the simulation model of the whole machine containing local damping loss is established. According to the parameter types affecting the cavitation and the corresponding values range, the orthogonal test scheme is designed, and the simulation analysis is carried out on this basis. The results show that the piston motion cycle is basically not affected by the factors and the corresponding level combination. The piston mass and the initial volume of the nitrogen chamber are the main factors affecting the minimum pressure of the piston rear chamber and the maximum velocity, and the minimum pressure and the maximum velocity are negatively correlated with the piston mass and the initial volume of the nitrogen chamber. Due to the rebound force, the piston does not stop after hitting the drill rod but immediately accelerates the return.