摘要
在飞机水上迫降过程中,其尾部吸力对姿态角的变化具有重要影响。基于Fluent软件,利用动网格技术、用户自定义函数(UDF)、六自由度(6DOF)模型、流体体积(VOF)模型,首先对二维圆柱、三维椭圆抛物体垂直入水以及三维平板水平划水进行数值模拟,并与试验结果对比验证模拟方法的可靠性;然后对NACA TN2929简化飞机模型进行水上迫降数值模拟。研究发现:尾部吸力使飞机俯仰姿态角发生剧烈变化,入水初期尾部吸力产生的抬头力矩使飞机姿态角快速增加,当姿态角达到最大时,尾部吸力产生的抬头力矩很小,在重力作用下飞机姿态角快速减小。本文所采用的三维数值模拟方法能够较好地模拟飞机水上迫降过程中的吸力和姿态角变化。
The rear fuselage suction force plays an important role in the change of attitude angle during aircraft ditching.Basing on Fluent software,using dynamic mesh method,user-defined function,six degrees of freedom model and volume of fluid model,on the beginning,the vertical water entry of 2Dcircular cylinder,3Delliptic paraboloid and the horizontal planing of 3Dflat plate are numerically studied in detail to validate the reliability of numerical simulation method by comparing with the test results;Then,the ditching of NACA TN 2929 simplified aircraft model is also simulated.The results of which show that the rear fuselage suction force makes the pitch attitude angle changed rapidly,the pitch-up moment of suction force makes the attitude angle increased quickly in water-entry early,when the attitude angle reaches the maximum,the pitch-up moment of suction force is very small,the gravity makes the attitude angle decreased quickly,and this method can be properly used to simulate the rear fuselage suction force and pitch attitude in ditching.
出处
《航空工程进展》
CSCD
2016年第1期51-61,共11页
Advances in Aeronautical Science and Engineering
关键词
飞机简化模型
水上迫降
数值模拟
动网格
吸力
姿态角
simplified aircraft model
ditching
numerical simulation
dynamic mesh
suction force
attitude angle
