Abstract: Experimental measurements and numerical simulations on the discharge coefficient of pre-swirl nozzles with pre-swirl angles 30°, 25°, 20° and 15°,respectively, were carried out under pressure ratio range 1.1~1.9. The effects of pressure ratio and pre-swirl angle on the velocity and flow angle at the nozzle inlet and outlet, discharge coefficient and pre-swirl effectiveness were investigated via CFD work. Experiment and CFD results of discharge coefficient coincide well with each other. Data show that the discharge coefficient and pre-swirl effectiveness increase with the increase of pressure ratio. It is observed that the decrease of pre-swirl angle will lead to an almost unchanged discharge coefficient,while the pre-swirl effectiveness raises remarkably because of decreasing flow exit angle, with a maximal increase of 10%. 

Key words: Pre-swirl system; Pre-swirl nozzle; Pre-swirl hole; Discharge coefficient; Pre-swirl effectiveness

摘要： 对预旋角度分别为30°,25°,20°和15°的预旋孔在压比1.1～1.9范围内的流量系数进行了实验测量和数值模拟。研究了压比和预旋角度对预旋孔进出口速度和气流角度、流量系数和预旋效率等参数的影响。流量系数的实验结果与计算结果符合良好,数据显示预旋孔流量系数和预旋效率随压比的增大显著增大。预旋角度的减小使流量系数基本保持不变,而预旋效率由于出气角度的减小而显著增大,最大增幅可达10％。 

关键词: 预旋系统;预旋喷嘴;预旋孔;流量系数;预旋效率