Design and Performance Evaluation of a Propeller

The selection of small-diameter propellers for Micro-Air Vehicle (MAV) applications are usually carried out arbitrarily due to non-existence of performance data. The presence of vast performance data for larger propellers cannot be applied to these small-diameter propellers that operate at low Reynolds numbers, and the aerodynamic performance data at these low Reynolds numbers seldom exists. Analytical method such as momentum-blade element theory together with computational methods such as CFD can be relied upon to design and optimise the performance of propellers of any class. In the current work, the design and performance evaluation of a propeller applicable to a MAV is carried out for a given thrust of 1 N, diameter of 120 mm and speed of 10,000 rpm. The design was based on one-dimensional momentum theory. Design modifications were done by varying the blade setting angle at 75% radius to enhance the performance of the propeller. As a result, the maximum efficiency was obtained for a blade setting angle of 40°. Experimental data available in the literature were used to validate the CFD solution procedure applied to predict the performance characteristics of the propeller.