In this paper, a simple but effective design for implementing a negative wing twist in a beetle-mimicking wing system is presented. The effectiveness of the design in terms of force generation and power consumption is confirmed by both experiment and calculation. An unsteady blade-element-theory model is used to estimate the aerodynamic forces produced by two different wing kinematics of a flapping-wing system. The model was first validated with the measurement data and two three-dimensional computational-fluid-dynamics results from the literature. The difference between the estimated average lift and the measured lift is 5.6%, which proves that the unsteady blade-element-theory model provides reasonable aerodynamic force estimation. The time history of the current estimation is also close to the measured data and is in between the two computational-fluid-dynamics results. The forces generated by the flapping wings with and without wing twist are estimated using the unsteady blade-element theory to investigate effect of the wing twist on the force generation. The result shows that the flapping-wing system with wing twist produces a 9.5% larger average vertical force or thrust while consuming 37% less power than the flapping-wing system without wing twist. The measured thrust by the swing test also shows 13.2% increase for the flapping wing with wing twist. Thus, by the estimation and measurement, it is confirmed that the wing twist improves the thrust generation.
Effect of Wing Twisting on Aerodynamic Performance of Flapping Wing System
AIAA Journal ; 51 , 7 ; 1612-1620
2013-07-01
Article (Journal)
Electronic Resource
English
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