基于大涡模拟的ROV导管推进器梢隙流动数值研究

Numerical research of the tip leakage flow in a ROV ducted propeller based on the LES method

导管推进器是一种普遍应用于无人遥控潜水器(ROV)等潜器中的特种推进器。在桨叶与导管之间的梢隙中存在非常复杂的流动,本研究基于大涡模拟(LES)对导管推进器的梢隙流动进行了数值模拟分析。通过对时间步长的收敛性研究,建立两套基于不同网格类型的计算模型。将计算与试验结果进行对比,比较两种不同类型网格模拟结果的差异,发现切割体网格能够更好地捕捉到泄涡的细节,并结合梢隙流场的原理分析了泄涡发展的过程,梢隙涡的驱动力是吸力面、压力面之间的压差。此外,随着进速系数增大,梢隙周向的涡管轴向分布范围减小,主泄涡发生位置延后,泄出涡的长度和数量都有所减少。

Ducted propeller is a kind of special propeller which is widely used in vehicle like Remotely Operated Vehicle(ROV).Complex flow exits between the blade and the duct.In this study,large-eddy simulation(LES)is used to study the tip leakage flow in a ducted propeller.Two sets of calculation models based on different grid types are established by studying the convergence of time steps.The hydrodynamic results are compared with the experimental data.By analysis the differences between the simulation results of two different types of mesh,it is found that the cutting body mesh can capture the details of the vortex better.And based on the principle of the tip flow field,the driving force of the tip vortex is considered as the pressure difference between the suction surface and the pressure surface.In addition,with the increases of advancement coefficient,the axial distribution of the vortex around the tip leakage is reduced,and the position of the main vortex is delayed,and the length and number of venting vortex are reduced.