螺旋桨边界层的实用计算方法与油膜实验

A Practical Method for the Calculation of Boundary Layers on Propeller Blades and Some Aspects of the Oil-Film Test

本文将作者提出的计算旋转螺旋面三维边界层的方法推广于螺旋桨桨叶表面边界层计算.为检验此法,进行了两个桨模的桨叶表面油膜流线实验.文中讨论了油膜流迹与桨叶表面实际的极限流线间发生偏离的多种影响因素,以及预估边界层转捩点的方法.数值计算表明,本文方法计算量小,收敛性好,结果可信.

The calculating method developed by one of the authors for the 3-D boundary layers on rotating helical blades is used to predict the boundary layer development on marine propeller blades. Oil-film tests were carried out on two propeller models for verification. It is pointed out that there are differences between the directions of the oil streaks and those of the limiting streamlines on the blade surface, and that the differences depend on several factors. So the oil-film test gives only qualitative results. In general, the transition position of the blade boundary layer can be roughly estimated by Cebeci-Smith's empirical formula, but the transition caused by the leading edge separation can be predicted only if the lifting surface codes for the calculation of the potential flow are capable of dealing with the details of velocity distribution around the leading edge. Numerical calculation shows that the method proposed is time-saving and has good convergency.