对旋风机转速改变对其气动特性的影响

对旋风机前后级转速比对风机气动特性影响较大,合适的转速比有利于提高对旋风机气动性能。采用数值计算和实验模拟方法研究对旋风机前后两级叶轮转速改变对风机气动特性的影响。首先,通过速度三角形定量分析转速改变对风机功率和内部流动参数的影响。之后,数值计算的结果与实验进行对比,分析基准转速下风机整体性能的变化。最后,通过数值计算结果对风机内部气体的流动进行具体分析,发现在保持进口条件不变的条件下,前后两级叶轮转速改变相同百分比时,第1级转速改变可以更加有效的改变风机的流动参数和性能,综合比较整体性能变化与实际应用确定了最优转速比为1.1∶1,此转速比下传动效率为88.4%时对旋风机效率为75%。

Influence of rotating speed variation on aerodynamic characteristics for counter rotating fan

The aerodynamic characteristics of counter rotating fan was effected by rotating speed ratio of first and second stages, appropriate speed ratio could improve aerodynamic characteristics of counter rotating fan. The influence of rotating speed variation of first and second stages on the aerodynamic characteristics of counter rotating fan was studied by numeral calculation and experiments. First, the influence of changes in rotating speed on powers and internal flow parameters was quantitatively analyzed by velocity triangle. Then, the results of calculation were compared with the results of experiment to analyze the performance of fan under the standard rotating speed. Finally, air flows in the fan were analyzed with the results of calculation. It is found that the flow parameters and performance of fan change more efficiently by changing the rotating speed of the first stage under the same rotating speed changing percentage of first and second stages when the conditions of inlet keep invariant. Combined with the performance of fan and the demand of reality, the most optimal rotating speed ratio is 1.1:1. The efficiency of counter rotating fan is 75% under this rotating speed ratio and transmission efficiency of 88.4%.