Development and Analysis of an Autorotating, Disposable Micro Air Vehicle for Tactical Surveillance

Abstract

The aim of this project was to further investigate the feasibility of a gas-gun-launched, disposable Micro Air Vehicle (MAV) for use in tactical situations. The MAV, once propelled to altitude by a gas powered initiator, utilises autorotation to reduce its terminal descent rate while inbuilt cameras capture the tactical situation below. The concept has the potential to greatly benefit ground forces in suburban areas by providing them with an instantaneous, fire and forget source of enhanced battle-field awareness. This project focused on the optimisation of the rotor blades for the MAV, particularly through blade twist. Vertical autorotation performance has been analysed by both computational and experimental methods; a MATLAB model founded on Blade Element Momentum Theory has been written and low turbulence wind tunnel experimentation has been conducted. The experimental results have shown that the terminal descent velocity of the MAV could be substantially reduced through the implementation of positive linear blade twist between 11o and 19.5o. The computational analysis produced has been proven to identify performance variation due to blade twist however was unable to recognise the peaks in performance identified by the experimental analysis. As such the MATLAB model will require further development before being utilised for future autorotation analysis and optimisation.