湍流中螺旋桨激振力宽频谱及参数影响研究

针对螺旋桨在湍流中的非定常激振力问题,文章介绍并推导了相关性法,在相关性法的基础上,重新定义了湍流速度相关性公式,并考虑了螺旋桨抽吸作用导致的湍流涡拉伸变形的影响,引入了拉伸系数ax,ay和az,推导了新的螺旋桨激振力宽频公式。同时,使用了十桨叶螺旋桨模型,分别采用相关性法和改进后的相关性法对其进行了计算并与试验值进行对比,发现改进后的相关性法能较好地预报螺旋桨激振力宽频谱,特别是在叶频处能与试验值符合较好。最后,在此基础上,研究了螺旋桨转速n、湍流积分尺度Λ和螺旋桨桨叶数N等参数对螺旋桨激振力宽频谱的影响。

Study of propeller broadband thrust spectrum and the effects of coefficient in turbulence

The correlation approach is introduced and deduced in the analysis of unsteady thrust problem of propeller in turbulence.Based on the correlation approach,the new correlation function of turbulent velocity is defined,meanwhile,the effect of distortion of turbulent eddies resulted from the pumping action of propel-ler is taken into consideration and stretched coefficients ax,ay and az are introduced.New propeller thrust spec-trum function is deduced.Two approaches are adopted to analyse ten-bladed propeller model and compared with experiment results.The analysis shows that the modified correlation approach has a better agreement with the experiment results,especially at blade frequency.The effects of rotation speed n,turbulence integral lengthΛand blade number N on thrust spectrum are studied with the new correlation method.