机翼热气防冰及冰脊形成数值模拟

应用N-S方程求解空气外流场和防冰腔内流场,用Euler法获得过冷水滴撞击特性,将内外流场进行耦合传热稳定后,开始结冰,来实现机翼热气防冰及冰脊形成的数值模拟.计算结果表明,热气防冰开启时,加热区蒙皮最低温度为286K保证加热区没有结冰,但在加热区后的上下表面由于蒙皮温度降低至273.15K以下,防冰区的溢流水到此处形成冰脊,这个计算结果表明了热气防冰数值模拟的可行性与合理性.但在将前缘积冰除去的情况下,防冰区外形成冰脊对气动特性影响很大,对带冰脊的机翼绕流流场进行数值模拟,对计算结果进行分析,得出环境温度越低、形成冰脊的位置越靠近防冰区,冰脊的高度越高;结冰时间越长,冰脊后的非定常特性越明显,流动细节的捕捉越困难,对气动特性的影响越大.

Numerical Simulation of Wing Hot Air Anti-Icing and Ice Ridge Formation

The N-S equation was used to solve the external air flow and the internal anti-icing cavity flow. The impact characteristics of the supercooled droplets were obtained by the Euler method. After the internal and external flow are stabilized by coupling heat transfer, it starts icing to achieve numerical simulation of wing hot air anti-icing and ice ridge formation. The simulation results show that when the hot air anti-icing system is turned on, the minimum temperature of the skin in the heating zone is 286 K to ensure that the heating zone has no ice, but the temperatures of the upper and lower wing surface behind the heating zone are reduced to below 273.15 K, and the water from the anti-icing zone runs here to form ice ridge. The analysis of the simulation results shows the feasibility and rationality of the numerical simulation of hot air anti-icing. However, in the case of removing the ice from the leading edge, the formation of ice ridge outside the anti-icing zone has a severe influence on the aerodynamic characteristics. Numerical simulation of the flow around the wing with ice ridge was carried out. It discloses that with a lower environment temperature, the ice ridge is higher and closer to the anti-icing zone; and with a longer icing time, the unsteady characteristics of the ice ridge are more obvious, the capture of the flow details is more difficult, and the influence on aerodynamic characteristics is more severe.