04-05-2011, 03:30 PM
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Numerical Simulation for Aerodynamic Characteristics of Low Altitude and Subsonic Flight Vehicle
Abstract—In order to analyze the drag characteristics of the vehicle having different war head and empennage, the computational fluid dynamics numerical simulation was used. The method was based on fully hexahedral mesh and three-dimensional Navier-Stokes equations and Spalart-Allmaras turbulence model. Through numerical simulation the flow field structures and computational aerodynamic characteristics were obtained. The results showed that using Kaman figure war head and proper trapeziform empennage can reduce the drag characteristics of the missile and the results will provide evidence to optimize the configuration of the missile in engineering design.
Keywords-drag characteristics; numerical simulation; stabilization; wrap around empennage; trapeziform empennage
I. INTRODUCTION
The velocity and flight altitude of the flight vehicle are low and the free flight is used for the control system. The drag of the flight vehicle includes the friction drag, drag induced by lift, the pressure differentia drag and interferential drag. The drag should be decreased and the stabilization should be enhanced at the condition of the tube-launching.
The computational fluid dynamics method was used to calculate the flow field of six cases with different warhead and empennage sharps. Some methods to decrease the drag were obtained and the results provided the reference for the design of the flight vehicle shape.
II. SIMULATION OF THE LOW ALTITUDE AND SUBSONIC FLIGHT VEHICLE
A. Conditions of the Simulation and the Flight Vehicle Shape
Fig. 1 shows the shape and the surface meshes of the flight vehicle. The short and thick shape was used at the restriction of the launching space. The shape is disadvantageous for the drag decrease and stabilization. Six cases including four factors were calculated to research the aerodynamics of the flight vehicle. Table 1 presents the calculated scheme. The flight velocity is subsonic and the flight attack angle is between 0~10 degree.