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

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.