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当前高超声速飞行器壁面黏性力的预测方法主要有精确的Novier-Stokes方程CFD方法(计算流体力学)和快速工程计算方法。前者计算精度高,但效率很低;后者效率极高,但精度难以满足工程应用要求。如何将两种方法有效结合,发展具有一定精度且效率也较高的壁面黏性力计算方法,一直是计算空气动力学研究的重要方向之一。为此,本文基于无黏Euler方程CFD方法获得的壁面流场参数,发展了一种更加精确的高超声速飞行器壁面黏性力快速工程计算方法。该方法以经典参考温度法为基础,以壁面当地流场参数替代自由来流参数,更加充分地考虑了高超声速复杂流动的特性,从理论上提高了壁面黏性力的预测精度。为验证该方法的准确性,以典型高超声速高升阻比飞行器外形为研究对象,分别采用精确Navier-Stokes方程CFD方法和本文发展的快速工程计算方法,预测了高空高马赫数飞行环境下飞行器壁面的黏性力;通过对比分析表明,本文所建立的快速计算方法预测偏差为10~20%,能够满足工程初步设计的要求。
At present, the prediction methods of the viscous force of the hypersonic vehicle wall mainly include the accurate CFD method (Computational Fluid Dynamics) and fast engineering calculation method of the Novier-Stokes equation. The former has high calculation accuracy but low efficiency; the latter is very efficient, but the accuracy is difficult to meet the engineering application requirements. How to effectively combine the two methods to develop a method for calculating the viscous force of the wall with a certain accuracy and high efficiency has always been one of the important directions in computational aerodynamics. Therefore, based on the wall flow parameters obtained by the CFD method of the non-viscous Euler equation, a more accurate calculation method for the visco-force on the wall of hypersonic vehicles has been developed. Based on the classical reference temperature method, this method replaces the free flow parameters with the local flow field parameters in the wall, and more fully considers the characteristics of hypersonic complex flow and theoretically improves the prediction accuracy of viscous force. In order to verify the accuracy of this method, taking the typical hypersonic LWR aircraft profile as the research object, the accurate Navier-Stokes equation CFD method and the rapid engineering calculation method developed in this paper are respectively used to predict the aircraft wall The comparative analysis shows that the prediction error of the fast calculation method established in this paper is 10 ~ 20%, which can meet the requirements of the preliminary design of the project.