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 C L at higher angle of attack and increased C D were observed for the model under propeller induced flow. With an increase in propeller rpm, the effects seen in C L and C D are increased further.Reynolds number rpm rotation per minute V ∞ freestream velocity α angle of attack (degree) INTRODUCTIONResearch into the field of MAVs has been active for a long time, yet understanding of its aerodynamics are more challenging in certain aspects. A plethora of literature exist on the aerodynamic investigation of MAVs but very few literature [1-3, 6-9] are available which addresses the aerodynamics of MAVs under propeller induced flow. Null, Noseck and Shkarayev [1] in their attempt to study the effects of propeller induced flow on the aerodynamics of MAV, adopted a test methodology in which the dynamic thrust data were collected at the test velocity from the motor/propeller mounted on a pylon at 0 o angle of attack and the data was resolved into horizontal and vertical component for all the angles of attack the propelled MAV model was tested. To decouple the direct forces created by the propeller on the total lift and drag measured on MAV model, the vertical component contributing to overall lift is subtracted from the lift data and the horizontal component contributing to forward thrust is added to the total drag data of the propelled MAV model. The results obtained shows that the propeller induced flow caused higher magnitudes of lift at higher angles of attack & delayed stall, but a detrimental effect on the drag coefficients, and a subsequent decrease in the lift-to-drag ratio at low angles of attack. However, they concluded that, due to the way the aerodynamic coefficients were calculated, the effects in the aerodynamic coefficients are partly a mathematical phenomenon. Experiments by Gamble and Reeder [2] on a MAV to study the propeller-wing interaction were

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