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徐一航, 刘伟. 横向喷流对低速大攻角细长旋成体非对称气动特性影响研究. 力学学报, 2023, 55(11): 2504-2517. DOI: 10.6052/0459-1879-23-251
引用本文: 徐一航, 刘伟. 横向喷流对低速大攻角细长旋成体非对称气动特性影响研究. 力学学报, 2023, 55(11): 2504-2517. DOI: 10.6052/0459-1879-23-251
Xu Yihang, Liu Wei. Study on the effect of transverse jet on the asymmetric aerodynamic characteristics of slender spinning bodies with low speed and large angle of attack. Chinese Journal of Theoretical and Applied Mechanics, 2023, 55(11): 2504-2517. DOI: 10.6052/0459-1879-23-251
Citation: Xu Yihang, Liu Wei. Study on the effect of transverse jet on the asymmetric aerodynamic characteristics of slender spinning bodies with low speed and large angle of attack. Chinese Journal of Theoretical and Applied Mechanics, 2023, 55(11): 2504-2517. DOI: 10.6052/0459-1879-23-251

横向喷流对低速大攻角细长旋成体非对称气动特性影响研究

STUDY ON THE EFFECT OF TRANSVERSE JET ON THE ASYMMETRIC AERODYNAMIC CHARACTERISTICS OF SLENDER SPINNING BODIES WITH LOW SPEED AND LARGE ANGLE OF ATTACK

  • 摘要: 采用风洞试验和数值模拟相结合的方法, 对雷诺数Re = 55000条件下细长旋成体有、无横向喷流时大攻角非对称特性进行了分析. 通过风洞试验发现了旋成体在法向和侧向进行喷流时其大攻角非对称气动特性与无喷流时的区别, 通过数值模拟方法对几个典型工况下旋成体有、无横向喷流时的非对称气动特性进行了分析, 揭示了喷流对旋成体非对称流动分离的影响. 通过风洞试验发现当细长旋成体进行法向控制时无喷流、喷流位于迎风区和喷流位于背风区的旋成体表现出了不同的非对称流动特性: 首先喷流位于迎风区时攻角范围在20º ~ 40º之间有喷流和无喷流旋成体所产生的侧向力方向相反, 攻角大于40º之后侧向力系数的方向发生了改变, 与无喷流时的侧向力系数方向相同, 但是其绝对值要比无喷流时的侧向力系数小. 其次喷流位于背风区时攻角在15º ~ 35º之间有喷流时的侧向力系数绝对值要明显比无喷流时大, 在随后的40º ~ 70º之间旋成体侧向力系数变化规律与无喷流的趋势相似. 当细长旋成体进行侧向控制时由于沿侧向的喷流所产生的直接力使得攻角范围在0º ~ 20º之间和大于45º时有喷流的旋成体侧向力系数绝对值要比无喷流时大, 但是攻角在25º ~ 40º之间时旋成体的侧向力系数绝对值减小, 甚至在35º时几乎为0. 通过数值模拟发现当细长旋成体进行法向控制时, 喷流位于迎风区和背风区时喷流都对有扰流片一侧的流动分离产生了影响, 使得其与无喷流时的流场结构不同. 无喷流时细长旋成体有扰流片的一侧首先发生流动分离, 但是当喷流存在时无扰流片的一侧首先发生流动分离, 从而导致了侧向力绝对值增大以及侧向力方向发生改变等现象. 当细长旋成体进行侧向控制时, 没有扰流片的一侧流动首先发生了分离, 有扰流片的一侧后发生流动分离. 旋成体有扰流片一侧由于喷流的影响在弹体喷嘴附近及后方产生了低压区, 无扰流片一侧的流动分离之后旋成体中后部分产生了高压区, 使弹体产生了沿z轴正向的侧向力, 这与喷流产生的直接力方向相反、大小相当, 从而出现了旋成体攻角在20º ~ 40º之间侧向力较小、甚至在35º时几乎为0的情况.

     

    Abstract: In this paper, a combination of wind tunnel tests and numerical simulations is used to analyse the large angle of attack asymmetric characteristics of a slender spinning body with and without lateral jets at Reynolds number Re = 55000. The wind tunnel tests reveal the difference between the large angle of attack asymmetric aerodynamic characteristics of the slender spiniform in the normal and lateral directions of the jet and those in the absence of the jet, and the asymmetric aerodynamic characteristics of the slender spiniform with and without the lateral jet under several typical operating conditions are analysed by means of numerical simulations. The wind tunnel tests reveal that the cyclone with no jet, jet in the windward region and jet in the leeward region exhibit different asymmetric flow characteristics when the elongated cyclone is controlled normal to the windward region. The direction of the lateral force coefficient changes after the angle of attack is greater than 40º, and is the same as the direction of the lateral force coefficient when there is no jet, but its absolute value is smaller than the lateral force coefficient when there is no jet. Secondly, when the jet is located in the leeward zone, the angle of attack between 15º and 35º with the jet is significantly larger in absolute value than without the jet, and the lateral force coefficient changes between 40º and 70º in the subsequent cyclone in a similar pattern to that without the jet. When the slender spinning body for lateral control due to the direct force generated by the jet along the lateral direction, so that the angle of attack range between 0º ~ 20º and more than 45º with the jet of the spinning body lateral force coefficient absolute value is greater than without the jet, but the angle of attack between 25º ~ 40º when the spinning body lateral force coefficient absolute value decreases, and even at 35º almost zero. Numerical simulations have shown that when the long, slender spiniform is controlled normal to the windward and leeward areas of the jet, the jet has an effect on the flow separation on the side with the spoilers, making the flow field structure different from that without the jet. In the absence of jets, the flow separation occurs first on the side of the slender spiniform with the spoiler, but in the presence of jets the flow separation occurs first on the side without the spoiler, resulting in an increase in the absolute value of the lateral force and a change in the direction of the lateral force. When the slender spiniform is laterally controlled, the flow is separated first on the side without spoilers and later on the side with spoilers. The spin body with spoiler side due to the influence of the jet in the vicinity of the nozzle and the rear of the cartridge produced a low-pressure area, no spoiler side of the flow separation after the spin body in the rear part of the high-pressure area, so that the cartridge produced a positive lateral force along the z-axis, which is the opposite direction of the direct force generated by the jet, the size of the same, so that the spin body angle of attack between 20º ~ 40º less lateral force, or even at 35º the situation is almost zero.

     

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