Calculation and analysis of aerodynamic characteristics for airfoils immersed in two-dimensional jet flow

二维射流中翼型气动特性计算与分析

School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China

Received: 18 June 2021

Abstract

In order to study the aerodynamic interaction of the airfoil and jet flow, the free streamline model and the panel method are combined to establish a calculation method for the aerodynamic characteristics of the airfoil in a two-dimensional inviscid jet flow. Using the assumption of constant total pressure difference and free streamline model to determine the vortex strength and position of the jet boundary, the aerodynamic force of the airfoil is solved by the vortex panel method, and the whole process is calculated by relaxation iteration. Firstly, the relevant theory in this paper is introduced, and the convergence and effectiveness of the present method are also tested. Next, the influence of the position and the ratio of jet height to airfoil chord on airfoil aerodynamics in the jet flow are studied. Finally, the momentum theory is used to analyze the aerodynamic characteristics of the airfoil in the jet flow. The results show that the aerodynamic characteristics of the airfoil in the jet flow is quite different from that in the freestream. When the jet flow is deflected, the airfoil will not only generate lift but also drag. The method in this paper can be used to study the aerodynamic characteristics of the airfoil immersed in the jet flow.

摘要

为研究射流与翼型间的相互作用，将自由流线模型与面元法结合，建立了二维无黏射流中翼型气动特性的计算方法。利用总压差不变假设和自由流线模型确定射流边界的涡强和位置，翼型的气动力采用涡面元进行计算，整个过程进行松弛迭代求解。对所提计算方法的理论进行了介绍，并对其收敛性和有效性进行了验证; 研究了翼型在射流中上下位置、射流宽度与翼型弦长比值对翼型气动力的影响; 利用动量理论对射流中翼型的受力特性进行了分析。结果表明: 翼型在射流中的气动特性与自由来流中差别较大，当翼型引起射流偏转时，翼型不仅会受到升力，还会受到阻力。文中所提方法可用于二维射流中翼型气动力的计算。