Experimental Investigation on Effect of Flapping Frequency on Aerodynamic Forces of Ornithopters

Document Type : Original Article

Authors

• Karim Mazaheri
• Abas Ebrahimi

Sharif University of Technology

10.22067/fum-mech.v21i1.7703

Abstract

Ornithopters, or mechanical birds, produce lift and thrust through flapping motion of their wings. Many factors affect this physical phenomenon, and here we investigate effect of flapping frequency on aerodynamic and inertial forces. A six component measurement balance is used here, which is calibrated using a standard loading procedure, which uses a least squares curve fitting. A stand is designed to hold the flapping wing system during the test. A data acquisition system is set up to record important data with acceptable sampling frequency. Aerodynamic performance of the vehicle for hovering (i.e. no wind) situation is investigated. Produced lift and thrust are measured for different flapping frequency, and shows the aerodynamic forces are affected by elastic deformation and inertial flapping forces. This information are being used for validation of unsteady flow simulations needed for engineering design of ornithopters, and will be used for design optimization, as well.

Keywords

• Flapping wing
• Unsteady forces
• Measurement

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