Aerodynamic Analysis Of A Bionic Ammunition And Numerical Simulation Of Flight Processes

As a new concept of ammunition, the bionic ammunition aims to imitate the creatures such as birds, fish, insects and snacks to maneuver in complex environment, which does not adapt the traditional power or flight trajectory but wanders in the air, ground or the surface of the water at the same time. In this paper, we focus on the bird-like bionic ammunition, whose size is equal to a medium-sized bird. The bird-like bionic ammunition flies in a low speed with a pair of flapping wings, which belongs to the low Reynolds number flow problems. Based on this background, the main research contents are as follows:a) After doing some research on the physics of natural flight of the birds, a three dimensional rigid flapping wing model is established. A numerical study on the unsteady aerodynamic performance of the rigid flapping wing is conducted by using the computational fluid dynamics software--FLUENT and the dynamic grid technology. Meanwhile, the effects of different motion parameters (such as the flapping amplitude and flapping frequency of the flapping wings) and the coming flow parameters (such as the velocity and the attack angle of the coming flow) on the lift coefficient, drag coefficient and pitching moment coefficient of the bionic ammunition are taken into account.b) Taking the flexible deformation of a flapping wing into consideration, the fluid-structure coupling method is adopted to combine the computational fluid dynamics (CFD) technology with computational structure dynamics (CSD) technology. In the Workbench platform, a numerical study on the unsteady aerodynamic performance of the three dimensional flexible flapping wing is conducted by using the system coupling model. In this case, the fluid domain and solid domain can be meshed separately and their solvers can be set separately as well. In addition, other things being equal, the influence of the rigid structure and the flexible structure on the aerodynamic characteristics can be taken into a comparison.c) In order to analyze the dynamic characteristics of the bird-like bionic ammunition, the six degree of freedom of the bionic ammunition model is established with the aerodynamic parameters got from the aerodynamic calculation results above.