Experimental investigation of lift and drag characteristics of a typical MAV under propeller induced flow

Abstract

Experiments were conducted on a micro air vehicle (MAV) model in a low speed wind tunnel to study the actual lift and drag experienced by the model under propeller induced flow by separating out the thrust force generated by the propeller by decoupling the motor-propeller from the model and mounting it on a second arrangement with minimal flow interference. Tests were conducted on the model at actual flight conditions - at a freestream velocity of 9 m/s (Re = 135000 based on root chord) with the propeller running at speeds ranging from 8000 to 10000 rpm. The lift and drag coefficients obtained from the model with decoupled motor-propeller arrangement are compared to those obtained from the model with attached motor-propeller for the same test conditions and justification is made in favor of the former method. Effects of propeller induced flow with respect to an increase in propeller rpm on the lift and drag characteristics of the model were also studied. Higher CL at higher angle of attack and increased CD were observed for the model under propeller induced flow. With an increase in propeller rpm, the effects seen in CL and CD are increased further.