水上飞机静水起飞过程水气耦合性能分析

采用多相URANS(unsteady RANS)方法,针对水上飞机静水起飞过程中的性能分析,提出了一种新的数值模拟研究思路。通过考虑起飞过程中气动力和水动力之间的耦合影响、升力和浮力对水线位置高度变化的影响以及阻力和发动机推力对模型前进速度的影响,得到模型起飞过程中的受力变化趋势。模拟前通过分别计算标准模型的气动力和水动力并与实验数据对比,对数值计算方法进行了验证,模拟过程中通过VOF(volume of fluid)方法实现对自由液面界面的捕捉,最后通过对静水起飞过程中模型受力变化进行分析并与实验结果比较,对本文中的水气耦合数值计算进行了验证,计算结果表明,水上飞机低压载状态起飞过程中所受总阻力是缓慢增加的,并不会出现往复;同时水线高度逐渐下降,下降速度逐渐加快,且不会出现埋艏现象。

Coupled Hydrodynamic and Aerodynamic Performance Analysis of Seaplane Take-off Process in calm Water

In this paper, a multi - phase URANS method is used to analyse the performance of seaplane during the process of hydrostatic take-off, and a new numerical simulation method is put forward. By considering the coupling effect between aerodynamic and hydrodynamic forces, the effect of lift and buoyancy on the height change of the waterline, as well as the influence of the resistance and the thrust of the engine on the forward speed of the model in the take-off process, the trend of forces are gotten in the process of taking off. The aerodynamic and hydrodynamic forces of the standard model are calculated separately and compared with the experimental data before the seaplane calm water take-off simulation to verify the numerical calculation method. The VOF method is used to capture the free surface during the simulation. Finally,the results are compared with the experimental results to validate the numerical calculation of the water-gas coupling. The calculation results show that resistance is slowly increased in the low ballast condition, and will not be reciprocated; at the same time the waterline height decreased gradually with the rate of descending gradually increased , and there will be no appearance of trim by head.