Design, analysis, fabrication and testing of mini propeller for MAVs

Design, analysis, fabrication and testing of propeller for low Reynolds number applications with proper matching of\ud propeller characteristics with that of mini electric brushless motors with appreciable increase in efficiency for use in micro air vehicles is very challenging work. A two bladed 6 inch diameter, variable speed, fixed pitch propeller, design, analysis, fabrication and tests were carried out in National Aerospace Laboratories. In view of its geometry and low Reynolds number in the range of 10,000 to 50,000, extensive use of computational tools like FLUENT, XFLR5 are used to characterize the airfoil in\ud 2D environment and also its thrust, torque and power were evaluated using FLUENT in 3D environment. Overall performance was also evaluated using indigenously built test set up for measuring the thrust and power using low speed wind tunnel of NAL. Structural analysis was carried out using ANSYS program. In view of its thin profile and to have good accuracy, initially the propeller was fabricated using rapid prototyping (RPT) using Acrylonitrile butadiene styrene (ABS-M30) material and the same was used to evaluate the static thrust and wind tunnel testing. Subsequently the propeller was fabricated using CFRP\ud material and the necessary aluminum mould was machined using 3 -Axis NC machine. Computed values were compared with the results from static and wind tunnel tests in uninstalled condition. The computed values are fairly in good agreement with the test results. Flight tests were carried out using NAL designed micro air vehicle “Black- Kite”