基于响应面方法圆柱形喷嘴结构优化研究

摘要

Nozzle is the core work component of high pressure water jet,its geometry structure characteristics directly influence the jet quality and work efficiency. The computational fluid dynamics (CFD)method was applied in study for the current widely used cylindrical nozzle flow field inside,with the maximum exit velocity as target variable,then the response surface method was used to op-timize the nozzle structure. The study results show that:the cylindrical nozzle axial velocity and pressure present approximate dual characteristic. The nozzle exit diameter,nozzle export cylindrical section length and nozzle contraction angle of nozzle exit velocity has remarkable effect on nozzle exit velocity,and the inlet cylindrical section length and diameter of the inlet has less effect on outlet veloc-ity. Among them,between the nozzle export cylindrical section length and the outlet velocity has approximately a linear relationship, while the export diameter and nozzle contraction angle to the exit velocity has parabolic relationship. The influence nozzle pressure drop factors are nozzle entrance and exit diameter,while the other factors such as nozzle export cylindrical section length,entrance cylindri-cal section length and contraction angle to the influence of the pressure drop can be ignored.%喷嘴是高压水射流的核心工作部件，其几何结构特征直接影响射流质量及工作效率。利用CFD方法对当前广泛应用的圆柱形喷嘴内流场进行研究，以最大出口速度作为目标变量，采用响应面方法优化喷嘴结构。研究结果表明：圆柱形喷嘴轴心速度与压力呈现近似对偶特性。喷嘴出口直径、喷嘴出口圆柱段长度及喷嘴收缩角对喷嘴出口速度有显著影响，喷嘴入口圆柱段长度及入口直径对出口速度影响较小。其中，喷嘴出口圆柱段长度与出口速度近似呈线性关系，而出口直径及喷嘴收缩角与出口速度呈抛物线关系。影响喷嘴压降的因素为喷嘴入口及出口直径，而其他因素如喷嘴出口圆柱段长度、入口圆柱段长度及收缩角对压降的影响则可以忽略。