旋转锥形射流的参数影响与试验研究

为了研究中心有一小孔(0≤d≤4 mm)的不同头数螺旋流槽的圆柱形结构加旋件的旋转锥形磨料射流特性,通过射流打击断面试验研究,确定加旋件头数、有无中心孔、圆锥收缩角、压力和靶距及其范围等喷头结构参数.采用单因素试验法分析各参数对射流断面形状的影响,得出影响趋势图以及回归分析方程.研究结果表明:射流断面形状为实心圆或圆环.随着工作压力的升高,圆环外径增大,内径几乎不变;单头加旋件的打击效果较2头、3头的差,即射流加旋不均匀;由于加旋件中心孔增大,射流断面外径逐渐减小,收缩角几乎不受影响.靶距存在最佳打击范围,靶距增大导致圆环外径增大,两者呈线性正比例关系.试验为优化喷头及加旋件的结构参数和工作条件提供依据,且为进一步提高射流性能奠定理论和试验基础.

Effects of nozzle parameters on rotating conical abrasive jet and experiments

To investigate the characteristics of abrasive jet from a conical nozzle,which is composed of a casing and a core with spiral-grooved cylinder,a series of jet impingement experiments were conducted.The parameters that can affect characteristics of jet include number of grooves,diameter of central hole in cone,working pressure,distance between nozzle outlet and target. The effects of every parameter on jet cross-section shape were investigated by single factor experiment method,a few regression equations were fitted based on the experimental data,and the reasons why those effects were shown are analyzed theoretically. The results showed that the jet cross-section shape is a solid circle or a ring. The ring outer diameter becomes larger with increasing working pressure,while the inner diameter of the ring is almost the same. The impinging load of jet with single groove on the target is lower than that with two or three grooves. With increasing diameter of central hole the outer diameter of jet cross-section is decreased gradually. The cone angle of jet is almost unaffected. There is an optimum range of target distance; the outer diameter of jet cross-section gets large nearly linearly with increasing target distance;meanwhile the inner diameter is expanded as well. These experimental results can provide the basis for nozzle and spiral grooves geometrical parameters optimization and working pressure determination,and establish a theoretical and experimental basis for further improvement in jet performance.