Study on the Unsteady Flow Calculation & Transient Mathematical Model of Vectoring Nozzle
|School||Northwestern Polytechnical University|
|Course||Aerospace Propulsion Theory and Engineering|
|Keywords||Thrust vector Mathematical model Finite volume Unsteady flow B-spline Function approximation Flux vector splitting Artificial viscosity Engine|
Thrust vectoring technology modern fighter agility, the stall maneuver ability, good flying qualities of the key technologies, it has become an essential technology for the fourth-generation fighter and third-generation fighter modified hot technology, has been more and more and more attention. Vectoring nozzle is a key component of the thrust vector to establish the mathematical model of the thrust vectoring technology, especially to carry out the vectoring nozzle engine as well as integrated flight / propulsion control research foundation, has a very important significance. This study is aimed at the establishment of the vectoring nozzle mathematical model to carry out. Has a complex three-dimensional unsteady characteristics of the flow in the nozzle flow, the establishment of a dynamic mathematical model has a more important engineering and theoretical value. This article by the CFD calculations vectoring nozzle performance parameters, such as flow coefficient, thrust coefficient and effective thrust vector angle and vectoring nozzle pressure ratio, area ratio and geometric deflection angle of the relationship between the data and the use of function approximation theory established vectoring nozzle dynamic mathematical model. The main work and contributions are as follows: 1. Jamson center finite volume method, and has improved its processing on the border, verified verified developed in this paper vectoring nozzle three-dimensional viscous flow calculation program correctness. 2. The program calculates a vectoring nozzle under different pressure ratio, area ratio and geometric deflection angle of 200 kinds of three-dimensional viscous flow field vectoring nozzle performance data. 3. The impact vectoring nozzle performance factors, pressure ratio, area ratio and geometric angle on the vectoring nozzle performance. 4. The nozzle flow separation and flow separation nozzle performance, as well as macroeconomic factors that lead to separation of the flow. 5. Unsteady flow and vectoring nozzle vectoring nozzle dynamic deflection process airflow unsteady flow calculation method vectoring nozzle unsteady flow field in an intermediate state of the engine and afterburner. 6. The analysis and comparison of the steady flow calculation results and non-fixed constant flow calculation results obtained a given steady flow calculation results and non-stationary often calculated results of basic consistency, so that engineering is often calculated by the constant or test to study vectoring nozzle as well as the establishment of the mathematical model provides a basis. 7. Research focus on high-resolution upwind finite volume method based on flux vector splitting Sieger Warming, Vn Leer, Roe and AUSM \spline fitting method as a basis, the establishment of a dynamic mathematical model of axisymmetric vectoring nozzle three free parameters.