Shape Optimum Design of Propeller Blade Operating in Low Reynolds Number Range.

Abstract

This study is concerned with a shape optimum design of a propeller blade operating in a low Reynolds number range, 1.0–2.0 ×10 5 . The objective is to minimize the power-required under the constraints on the thrust and the angle of attack in terms of chord length and twist angle distributions where the power-required is evaluated by 3-D panel method. The profile drag is also considered in the optimization, because the effect cannot be ignored in a low Reynolds number range. For calculation efficiency, the profile drag coefficient is approximated by higher order polynomials in terms of Reynolds number and angle of attack. The effectiveness of the proposed method is demonstrated by the design of a propeller blade of a human-powered aircraft. Additionally, effect of the profile drag is discussed by comparing the designs with and without considering the profile drag.