基于凹槽结构的导管螺旋桨梢部流动研究

Analysis of tip flow of ducted propeller based on groove structure

针对导管螺旋桨的梢部流动,受压气机中“机匣处理”的启发,将矩形凹槽结构应用于导管内壁,用于降低导管螺旋桨梢涡强度和抑制梢涡空化,进而有望改善导管螺旋桨的水动力和空泡性能。采用计算流体力学方法,针对19A导管和Ka4-70螺旋桨有无凹槽/不同凹槽结构进行非定常数值计算,研究凹槽结构对桨叶叶梢压力、梢涡强度、梢涡结构以及水动力性能的影响。结果表明:凹槽结构会明显改变导管螺旋桨梢部流场涡的形成,减弱梢涡强度,提高叶片梢部最小压力,并且对推进性能几乎没有影响。研究结果可为导管螺旋桨的梢涡控制以及减振降噪提供一种新的解决途径。

Inspired by the“casing treatment”in turbomachinery,a rectangular groove structure is applied to the inner surface of ducted propeller to reduce the strength of the tip vorticity and inhibit the cavitation of tip vorticity,which is expected to improve the hydrodynamic and cavitation performance.The unsteady numeri-cal calculation of Ka4-70 propeller operating inside duct 19A,with or without grooves,was carried out by us-ing computational fluid dynamics(CFD)method.The influence of groove structure on tip pressure,tip vortex strength,tip vortex structure and hydrodynamic performance of blades was studied.The results show that the groove structure can significantly change the tip vortex of duct propeller,weaken the strength of vortex,in-crease the minimum pressure at the tip of blade,and almost have no effect on the propulsion performance.The results provide a new solution for tip vortex control and vibration and noise reduction of the ducted pro-peller.