Numerical Simulation And Theoretical Study On Aerodynamic Performance Of Flapping Wings

In recent years, a great deal of attention has been focused on Flapping Micro Air Vehicle(FMAV) with the rapid development of micro-nanometer technology. Reynolds number of these aircraft is commonly between 1.00×10-1.00×104, the sticky effect of airflow is enhanced obviously, but traditional steady flow field will bring the shortage of the lift, low efficiency and unstability, etc. However, birds and insects in nature fly with flapping the wings, these animals obtain obviously the thrust and lift with unsteady flows.In the paper, the parameters of flying is confirmed by means of bionic principle. Unsteady flow characteristics of FMAV is researched numerically by using computational fluid mechanics software FLUENT including User-Defined Function and dynamic grid technology through solving Navier-Stokes equation. Three kinds of flapping mode:advanced mode, symmetry mode and delayed mode are simulated, and aerodynamic characteristics of three flapping mode of single-wing model and double-wing model is analysed.In the paper the main research work embodied in the following aspects:1. The calculative method. Mastering the computational fluid mechanics software FLUENT, the application of dynamic grid technology and the secondary development function—User-Defined Function. Be familiar with the C programming language.2. Building single-wing model, the selection of the motion equations and Setting the related parameters are confirmed. Harmonic motion and three modes including advance mode, symmetry mode and lag mode of single-wing model are studied numerically mainly from two ways of the pressure and velocity vector.3. In the aspect of theory, introducing simply Weis-Fogh mechanism and circulation of Weis-Fogh mechanism under no space and space. In the aspect of numerical calculation, t three modes including advance mode, symmetry mode and lag mode of double-wing model are studied mainly from three aspects of vortex, pressure and velocity vector. Aerodynamics characteristics of advanced mode of two-dimensional double-wing model under different control flying parameters are discussed. These are not involved before. The main innovation points in the paper presented the following aspects:1. Three flying modes including advanced mode,symmetry mode and delayed mode of two-dimensional single-wing model, are simulated by using computational fluid mechanics software FLUENT including UDF and dynamic grid technology from two aspects of pressure and velocity vector.2. Three flying conditions including advanced mode,symmetry mode and delayed mode of two-dimensional double-wing model, is studied by using fluid mechanics calculative software FLUENT and the secondary development function from three aspects of vortex, pressure and velocity vector.3. Aerodynamics characteristics of advanced mode of two-dimensional double-wing model under different control flying parameters is discussed.