为了解翼型以不同加速度启动时的流动特性,采用基于动网格方法的有限体积法对翼型瞬态启动引起的二维不可压缩非定常流动进行了数值计算,并结合网格局部重构的方法保证翼型运动时周围的网格质量.计算了启动加速度分别为50mm/s^2和100mm/s^2时,绕翼型非定常流动的结构及其演化过程,并分析了加速度大小对流动结构的影响.结果表明,翼型在加速运动和匀速运动过程中均形成了复杂的旋涡结构;大加速度下非定常流场中的旋涡运动、扩散和耗散速度明显比小加速度下的要慢,并且大加速度下旋涡结构更紧凑,运动更为强烈.
To study flow characteristics of hydrofoil starting at different accelerations, the finite volume method based on dynamic mesh method was adopted to simulate the two-dimensional incompressible unsteady flow caused by impulsively started hydrofoil, and the local grid remeshing method was also used to ensure gridquality of the moving boundary. The structure of the unsteady flow and its evolving process at two uniform accelerations of 50 mm/s^2 and 100 mm/s^2 were calculated, and the effect of acceleration on the structure of unsteady flow was analyzed. Results show that a complex vortex structure is generated during both the acceleration phase and the constant velocity movement phase. The speeds of vortex movement, diffusion and dissipation at larger acceleration are obviously smaller than that at smaller acceleration, and the vortex structure is more compact and the vortex movement seems to he stronger.