摘要
Under the absolute coordinate system, the unsteady Reynolds averaged Navier-Stokes(URANS)equations and the k-ω SST turbulence model are solved using the finite volume method to simulate the aerodynamic characteristics of large seaplane flying with the ground-effect above wavy surface. The velocity inlet wave-making method and the volume of fluid model are used to accurately simulate the linear regular waves and to precisely capture the free surface. This paper studies the influence of the sideslip angle on the aerodynamic characteristics of large seaplane when it is cruising above wavy water. The results show that the wave surface mainly affects the pressure distribution on the lower surface of the wing. When the sideslip angle varies from 0° to 8°,the varying of frequency of aerodynamic forces is consistent with the wave encounter frequency,and both periods are 0.6 s. With the increase of the sideslip angle,the lift coefficient and the pitching moment coefficient decrease. However,when the sideslip angle is smaller than 4°,the decrease amplitude is small,and the significant decrease occurs above 4° and during the whole process of the change of sideslip angle,the aerodynamic fluctuation amplitude is almost unchanged. As the drag coefficient increases with the increase of sideslip angle,significant increase also occurs when the value is greater than4°,and the fluctuation amplitude does not show any correlations. The rolling moment coefficient and yaw moment coefficient increase with the increase of the sideslip angle,and the fluctuation amplitudes of both increase linearly with the increase of the sideslip angle.
在绝对坐标系下,求解基于有限体积法的非定常雷诺平均Navier-Stokes(URANS)方程和k-ωSST湍流模型,模拟大型水上飞机在波面地效应区飞行时的气动特性。采用速度入口造波法和流体体积分数模型对线性规则波进行了精确模拟,并对自由表面进行了精确捕捉。本文主要研究了大型水上飞机在波浪水面上巡航时侧滑角对其气动特性的影响。结果表明:波浪水面地面效应主要影响机翼下表面的压力分布。当侧滑角在0°~8°范围内变化时,气动力的变化频率与波浪相遇频率一致,周期均为0.6 s。随着侧滑角的增大,升力系数和俯仰力矩系数均减小。然而,当侧滑角小于4°时,下降幅度较小,当侧滑角大于4°时,下降幅度显著,在整个侧滑角变化过程中,气动波动幅度几乎没有变化。阻力系数随侧滑角的增大而增大,当侧滑角大于4°时也出现显著增大阶段,且波动幅度不存在相关性。横摇力矩系数和横摆力矩系数均随侧滑角的增大而增大,其波动幅度均随侧滑角的增大而线性增大。
作者简介
LI Yanghui,received the B.S.degree and the M.S.degree in aircraft design from Nanjing University of Aeronautics and Astronautics in 2018 and 2021,respec⁃tively.His research interests include multi-phase flow and fluid-structure interaction;Corresponding author:TONG Mingbo,Mingbo received his Ph.D.degree in solid me⁃chanics from Beijing University of Aeronautics of Astronau⁃tics in 1995.His research interest includes solid mechanics and aircraft design and analysis.E-mail adress:tongw@nuaa.edu.cn
