Research Of The Initial Trajectory Simulation Of The Missile Released By Aircraft

The investigation of the distribution of aerodynamic forces on the external stores and their neighboring aircraft surfaces during the transient process of the separation of the external store from an aircraft is an urgent need because aerodynamic interactions can cause the released store to impact upon, and possibly damage, the aircraft. The development of CFD(Computational Flow Dynamics) numerical simulation presents a common and powerful solution for the class of problems and will therefore be of considerable benefit in store design with the potential of reducing experimental and flight testing costs.At the same time, the appearance of the dynamic mesh calculation technology supplies us a method that can be used to model flows where the shape of the domain is changing with time due to motion on the domain boundaries.This paper provides a powerful method for the compatibility design of aircraft with external store, a missile, by calculating fast, conveniently and effectively the relative trajectory and relative attitude of the store with respect to aircraft during the separation process. The work of this paper include:1. The 3-D solid entities of the external store, a missile, and the aircraft are modeled with a commercial CAD software.2. The unstructured meshes of the global flowfield are made.3. The program to solve the six-freedom-of-degree dynamics equation and the kinematics equation of the missile are worked out.4. The method of using the commercial CFD engineering software FLUENT to integrate the dynamic mesh calculation technology with the CFD numerical simulation also is described. To use the dynamic mesh model, it is necessary to provide a starting volume mesh and the description of the motion of any moving zones in the model. This paper describes the motion using a C program, a user-defined function (UDF), to calculate the linear and angular velocities from the force balance on the store.The analysis of the results from the numerical simulation shows fairly good effect and it concludes the method can be effectively used to solve the different problems of the similar fields.