Abstract
An advanced generation of UAVs (Unmanned Aerial Vehicles) with ducted fan is being fabricated for a wide range of missions comprising investigation, inspection, and combat missions. In addition, there are developments to cover several roles such as meteorological studies, traffic control and hazard mitigation etc. This paper presents widespread results experimentally acquired for investigating the aerodynamic characteristics as effect of tip clearance on small UAVs with ducted fan. Three samples of ducted fans with varying tip clearance but same rotor size was studied with three diverse yawed conditions. 3D velocity flow fields were measured from root to tip for a ducted fan’s inlet and outlet. The data was acquired with calibrated slanted hot-wire anemometer by Phase-Locked Ensemble Averaging Technique (PLEAT). Non_x0002_linear differential equations are simultaneously resolved with Newton–Raphson method. The flow field characteristics through axial, tangential and radial velocity contours were analyzed for tip vortex and secondary flow. The effects of tip clearance were investigated through wind tunnel on axial thrust. To achieve an enhanced ducted fan performance, tip clearance needs to be optimized.