翼型湿空气非平衡凝结流动的数值研究

 湿空气非平衡凝结会对机翼的气动特性造成显著影响。通过对Fluent软件进行二次开发，发展了一种求解湿空气非平衡凝结流动的数值方法并进行了验证。对NACA0012翼型在迎角为0°和1.5°时的湿空气非平衡凝结流动进行了分析。结果表明：与干空气流动相比，在30％～70％相对湿度范围内，湿空气非平衡凝结流动中升力系数显著降低，而阻力系数则可能增加或减小；0°迎角条件下，压差阻力系数最大增加了68.3％；在迎角为1.5°时，升力系数最大减小39.8％，而压差阻力系数最大减小了34.8％。造成翼型气动特性显著变化的原因在于：湿空气中水蒸气凝结放热对跨声速气流加热，导致翼型表面附近的流速、压力与流场结构发生了显著变化。

Numerical Investigation of Moist Air Flow with Non-equilibrium Condensation Around Airfoils

The aerodynamic characteristics of airfoil are significantly influenced by non-equilibrium condensation of moist air. Based on the Fluent software, a new algorithm is developed to simulate the moist air flow with non-equilibrium condensation. Numerical simulation is implemented to investigate the condensing flow of moist air around the NACA0012 airfoil at 0° and 1.5° angles of attack respectively. Results show that compared with the dry air flow, the lift coefficient decreases obviously whereas the drag coefficient may increase or decrease at the relative humidity of 30%-70%. At 0° angle of attack, a maximum drag increase of 68.3% is observed. At 1.5° angle of attack, a maximum lift decrease of 39.8% and a maximum drag decrease of 34.8% are found out. The mechanism leading to the significant change of aerodynamic characteristics of airfoil is analyzed. With the condensation of water vapor in moist air, latent heat is released and added to the surrounding transonic air flow. As a result, the velocity, pressure and flow field structure of the moist air flow are significantly changed.