Studies have shown that micro-wedge vortex generators(MVG)can effectively control the flow separation of supersonic boundary layer.In order to improve the flight stability of spinning projectile,the original standard ...Studies have shown that micro-wedge vortex generators(MVG)can effectively control the flow separation of supersonic boundary layer.In order to improve the flight stability of spinning projectile,the original standard 155 mm projectile was taken as an example,and the micro-vanes were mounted at the projectile shoulder to investigate the separation control on the aerodynamic characteristics of projectile.Numerical simulations were performed with the use of DES method for the flow fields of projectiles with and without micro-vanes,and the characteristics of the boundary layer structures and aerodynamic data were compared and discussed.Numerical results show that the micro-vanes can be used to inhibit separation of fluid on projectile surface,and improve the flight stability and firing dispersion of projectile.展开更多
文摘Studies have shown that micro-wedge vortex generators(MVG)can effectively control the flow separation of supersonic boundary layer.In order to improve the flight stability of spinning projectile,the original standard 155 mm projectile was taken as an example,and the micro-vanes were mounted at the projectile shoulder to investigate the separation control on the aerodynamic characteristics of projectile.Numerical simulations were performed with the use of DES method for the flow fields of projectiles with and without micro-vanes,and the characteristics of the boundary layer structures and aerodynamic data were compared and discussed.Numerical results show that the micro-vanes can be used to inhibit separation of fluid on projectile surface,and improve the flight stability and firing dispersion of projectile.
文摘发展风电、光电等可再生能源是国家战略需求.为了适配风、光等可再生能源波动性强的特征,储能系统的研究至关重要.以二氧化碳(CO_(2))为工质的热泵发电储能系统在能量密度、环境适应性和投资等方面具备优势,是备受关注的新型储能技术.本文基于提出的CO_(2)热泵发电储能系统,重点获取系统充注、热泵系统启动运行、热泵发电系统切换、发电系统启动运行的全工作阶段响应特性,提出了系统内部CO_(2)工质的质量评估方法,考察CO_(2)工质在压力容器、换热部件及管路中随全工作阶段的动态分布及容量迁移量化规律.结果表明,热泵系统在启动准备阶段其闪蒸罐及蒸发器占据CO_(2)总容量的61.2%,随着热泵系统运行,闪蒸罐内液态CO_(2)迁出,蒸发器及冷却器容量均增加,闪蒸罐气液容量分布主要受压力影响而冷却器的容量增长幅度则主要取决于运行温度.切换及发电系统运行阶段,缓存罐承担主要容量迁移,切换完成时增加4600.6 kg、运行时则降低1863.6 kg.
