Flow visualization and force measurement of the clapping effect in bio-inspired flying robots

In this paper, we perform experimental investigations of the aerodynamic characteristics due to wing clapping in bio-inspired flying robots; i.e., micro-air-vehicles (MAVs) that fly by flapping their wings. For this purpose, four flapping MAV models with different levels of clapping (from no clapping at all to full clapping) are developed. The aerodynamic performance of each model is then tested in terms of the average thrust and power consumption at various flapping frequencies. The results show that clapping enhance both thrust and efficiency. To gain some physical insight into the underlying physics behind this clapping-thrust-enhancement, we perform a smoke flow visualization over the wings of the four models at different instants during the flapping cycle.