翼身融合水下滑翔机翼梢小翼减阻效应研究

Research on drag reduction effect of winglet applied in blended-wing-body underwater gliders

针对翼身融合水下滑翔机,利用计算流体力学方法,获得了加装翼梢小翼前后水下滑翔机的流体动力特性.以翼梢小翼高度、前缘后掠角、外倾角为外形参数,对比得到不同翼梢小翼外形与减阻效率之间的关系.通过观察有翼梢附近的尾部流场,对翼身融合的水下滑翔机翼梢小翼的减阻原理进行了分析.不同翼梢小翼减阻效果对比表明：在速度一定的条件下,翼梢小翼会对水下滑翔机翼梢尾部流场涡的形成产生显著影响,合理的翼梢小翼能降低翼尖涡强度,抑制涡的产生,在一定攻角范围内达到减阻效果.

This paper aims to explore the effect of winglet equipped in blended wing body（BWB） underwater gliders.Computational fluid dynamics（CFD） method was used to obtain the fluid dynamic characters of BWB underwater gliders.The drag reduction efficient of different glider models with different height,sweep angle and slope angle under variable angles of attack were obtained and analyzed.Wake flow of different models was observed and the principles of drag reduction were analyzed.Comparisons between different models reveal that the vortex in wake flow is significantly affected by the winglet in a certain velocity.A proper winglet helps reducing the vortex magnitude and inhibits the occurrence of the vortex.As a result,the drag decreases in certain angles of attack.