• 论文 •

### 底凹结构减阻效应数值分析

1. 南京理工大学 能源与动力工程学院, 南京 210016
• 收稿日期:2020-11-09 发布日期:2022-04-27
• 通讯作者: 王良明 E-mail:lmwang802@163.com

### Numerical analysis on drag reduction effect of base cavity

LI Biao, WANG Liangming, YANG Zhiwei

1. School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210016, China
• Received:2020-11-09 Published:2022-04-27

Abstract: In order to investigate the drag reduction mechanism of the base-cavity projectile, the flow field characteristics of M910 projectile are numerically simulated through the 3-dimensional steady CFD method. The zero-lift drag coefficient variation with Mach number are presented. The computational results have a good agreement with the experimental data. On this basis, a base cavity is introduced for M910 projectile that is named M910BC in this paper and then numerically simulated. The base flow field characteristics of the projectile with different base structures are compared and the drag reduction mechanism of the base cavity is analyzed. The results show that at subsonic speed, the drag reduction of the base-cavity projectile is found to be mainly due to the introduction of the high-pressure "dead zone" in base cavity and the displacement of the solid base with the compliant fluid boundary of the cavity base. Because of that, the forming location, shape and strength of the wake vortex are slightly changed. At transonic speed, the drag reduction effect of base cavity is vanished since the wake vortex is further from the base of projectile and the effects of the solid base and fluid boundary are the same. At supersonic speed, the drag reduction mechanism of the base cavity is that the mass of the recirculation region is increased by the flow of the base cavity, which is similar to the drag reduction mechanism of the base bleed projectile.