The Initial Exploration How The Coming Flow And Wing Flapping Mode Influence The Aerodynamic Parameters Of Micro Aerial Vehicles

Micro aerial vehicle(MAV) can be effectively used for search and rescue, surveillance, information gathering and battlefield communications because of its light weight and ease of movement., so the research in this field over the world is unusually active and competitive. Currently the most research focused on the principles how the insect produces high lift and the researches on another key question how MAV flies stably in the natural environment are inadequate. In this paper, a numerical investigation on the aerodynamicperformance of an unsteady flapping motion generated by a simplified model of an insect's flapping-wing (3D) at low Reynolds numbers has been carried out using the finite volume method. It is found that the unsteady flow makes the insect flapping wing to generate some specific aerodynamic performance at the low Reynolds number in this study. The details of study and main conclusions are listed as following.Firstly, the change of lift, drag and moment, applied on the insect or other animals with flapping-wing, was calculated and analyzed in the case of the coming flow which has different direction and constant velocity. It is found that the lift, drag and moment, applied on the insect, would change, when the flow velocity increases. While the flow velocity increases to some degree, the lift will decrease, the drag will increase and the moment, which can make the body of the animals with flapping-wing rotate, will increase too. In order to fly stably and save energy, the insect can change the lift, drag and the moment by changing the flight velocity and the attack angle of the body.Secondly, the change of lift, drag and moment, applied on the insect or other animals with flapping-wing, was calculated and analyzed while the coming flow which has constant direction and different velocity. It could be concluded that the smaller the angle between the flight direction of the insect and the wind direction is, the better for the flight, by the calculating results. When the angle increases, the lift, drag and the moment that can make the body rotate will be increased all.Finally, the change of lift, drag and moment, applied on the insect or other animals with flapping-wing, was calculated when the coming flow has constant direction and constant velocity. It could be found that the angle between the axis of the wing and the axis of the body will influence the flight. The larger the angle is, the lager the ratio between the lift and the drag become and the smaller the moment which can make the body rotate will be, the easier the insect flight and the more useful for the insect save energy in flying process. The present results will provide useful information for MAV's design in the future.