基于预处理方法的冲压式翼伞非定常气动特性数值研究  

Preconditioning Numerical Simulation of Unsteady Aerodynamics of Ram-Air Parachutes

作　　者：李扬[1] 夏刚[1] 秦子增[1] 

机构地区：[1]国防科技大学航天与材料工程学院,长沙410073

出　　处：《航天返回与遥感》2004年第2期1-4,共4页Spacecraft Recovery & Remote Sensing

摘　　要：开展绕冲压式翼伞内外一体化流场的二维、不可压、非定常数值模拟。采用预处理的双时间步长方法 ,研究了冲压式翼伞在有攻角飞行时阻力、升力的瞬态特性和非定常旋涡脱落对翼伞气动力的影响问题。气动力特性的计算值与实验结果吻合较好 ,并观察到升力和阻力在大攻角飞行中的周期性变化规律。同时流场的瞬态特性证实上翼面旋涡的发展与运动是导致翼伞气动力脉动的主要原因。计算发现在前缘切口的冲压作用下 ,翼伞内部的压力较高 ,气流几乎保持滞止 ,这是维持翼伞充气外形的主要原因。2-D flows past ram-air parachutes was computed using and unsteady time-derivative preconditioning method for Navier-Stokes equation. Dual time-stepping scheme was used to flow at different angles of attack with leading edge cut. The leading edge cut causes the flow to become unsteady and leads to a significant loss in lift and an increase in drag. The flow inside the parafoil cell remains almost stagnant, resulting in a high value of pressure, which is responsible for giving the parafoil its shape. The value of the lift-to-drag ratio obtained with the present computations was in good agreement with those experiment data reported in the literature. Temporally periodic lift coefficient variation was observed,which is due to the leading edge cut induced periodic vortex shedding on the upper surface of the parafoil.

关 键 词：冲压式翼伞 非定常 降落伞 空气动力学 预处理方法 不可压流动 

分 类 号：V445.23[航空宇航科学与技术—飞行器设计]