Three-Dimensional Micro Propeller Design by Using Efficient Two Step Optimization

Abstract

A practical and efficient optimal design procedure is presented for three-dimensional micro-propeller. To manage many design related variables and operating conditions efficiently, the design procedure consists of two steps for optimization of operating conditions and blade geometries. First, operating condition points are extracted from the design-of-experiments, and provided as the input data of the geometry optimization step. Next, in the geometry optimization step, the 2-D airfoil shapes are optimized to provide the maximum lift-to-drag ratio along the radial blade section by using the XFOIL code, and the 3-D blade shapes are determined at the each operating condition by using the minimum energy loss method. Then, the performances of the optimized blade are calculated, and a Response Surface Model is constructed to decide the operating condition for the maximum propeller efficiency. To find the blade shape with better performance than the optimum shape in the initial design space, the design space is modified to a highly feasible design space by using the probability approach. Finally, the performance of the optimized propeller is compared with that of the Black Widow MAV propeller. The comparison showed that the optimized propeller had somewhat better performance. The present optimal design procedure is reliable and can be used as a practical design tool for micro propeller development.