Numerical Analysis for Circulation Distribution of Propeller Blade

A process for numerical analysis of radial circulation distribution of propeller blade is proposed and presented. It is based on the results of numerical simulation of the velocity field around propeller blades and in the wake. The well-known traditional method using tangential velocity data in the wake and applying Stockes's theorem was also examined in the investigation. The results from two approaches are compared with each other. It is found that if the traditional way is utilized, in many cases an unexpected “hump” appears in the circulation distribution at certain outer radius. The authors calculated the circulations directly around blade sections, and it is referred as direct method. The unexpected hump of the circulation distribution disappears in the results of direct method. This article also discusses the reasons of the appearance of the unexpected hump in traditional approach. The direct method is proposed to have a potential in analyzing or verifying the radial road distribution for designed propeller and the numerical analysis instead of experimental validation for circulation distribution can be as a tool in the propeller design process.