Abstract: 2D-planar particle image velocimetry (PIV) was utilized to investigate the effects of swirl number combinations on flow characteristics of triple-swirlers. The studied triple-swirlers have the same rotational combination with clockwise inner swirler，counter-clockwise intermediate swirler and counter-clockwise outer swirler. The inner swirl number，intermediate swirl number and outer swirl number are 1.4，1.0 and 0.6 for scheme B，while 0.6，1.0 and 1.4 for scheme A respectively. The total pressure loss coefficients were also obtained in different inlet Reynolds numbers. The experimental results show that obvious Central Toroidal Recirculation Zones (CTRZ) can be formed by the both two swirl number combinations，and the CTRZ of scheme B shows much plumper than the CTRZ of scheme A. The recirculated velocity of scheme B presents higher，the inlet Reynolds numbers has significant effects on length and size of CTRZs. The scheme A has a higher total pressure loss coefficient with a magnitude about 10% than scheme B in conditions of different inlet Reynolds numbers.

Key words: Swirl number combination；Central toroidal recirculation zone；Triple-swirler；Reynolds number；Total pressure loss coefficients

摘要： 采用2D-PIV流场测试技术，试验研究了旋流数组合方案对流场特性的影响。试验针对旋向组合为“顺时针-逆时针-逆时针”的三级旋流器，测量了内级、中间级和外级旋流器旋流数分别为0.6，1.0，1.4(方案A)和1.4，1.0，0.6(方案B)两旋流数方案旋流流场。同时测试了不同来流雷诺数条件下两方案三级旋流器总压损失。试验结果表明:两旋流数组合方案均能形成较明显的中心回流区，方案B中心回流区较方案A“饱满”，方案B中心回流区回流速度大；进口雷诺数对旋流器流场中心回流区长度、尺寸有一定的影响；不同进口雷诺数条件下，方案A总压损失系数较方案B约大10%。

关键词: 旋流数组合；中心回流区；三级旋流器；雷诺数；总压损失系数