Simulation And Research Of Aircraft Aerodynamic Characteristics Based On FLUENT

The aerodynamic characteristics and aerodynamics of aircraft are closely related to its construction and main units layout. They can embody aircraft flight characteristics and he index of the performance. In order to figure out whether the affect of initial conditions and control system are satisfied with actual demand, this paper performs an aerodynamic simulation and verification to the aerodynamic characteristics of an aircraft and control system with Fluent and MATLAB, respectively.This paper analysis the mechanical condition during aircraft is moving on air and define the relevant coordinate system of space for simplifying aircraft motion, then the conversion formula between coordinate systems is obtained. The relationship between moment of force which aircraft is suffered and aerodynamic parameter is studied. Simply the flight motion and establish math model accordance with theory. Space perturbation motion equation is obtained by analyzing and simplifying aircraft motion equations with small perturbation theory. Model aircraft with Gambit, confirm calculation zone and mesh generation. Due to the affect of calculation model, aerodynamic simulation is based on appropriate calculation model and turbulence model with Fluent. Finally, transformation rule is obtained, which aerodynamic characteristics change with initial conditions.According to the aerodynamic characteristics and the data of control system, disturbed motion of aircraft is divide into vertical one and lateral one. transfer function of pitch and yaw is calculated thought Coefficient freezing method. Analyze stability of vertical disturb accordance with settings initial conditions up and get parameter of the transfer function. It takes the actuator loop as input to vertical control system and optimize the pitch loop and highly loop with MATLAB toolbox. The result shows that electronic rudder system and vertical control system meet the requirements of time domain and frequency domain, which can be applied on aircraft control system.