Bi-stable asymmetry on a pointed-nosed slender body at a high angle of attack

2021 ◽  
Vol 130 (2) ◽  
pp. 024703
Author(s):  
Zhongyang Qi ◽  
Siyu Zong ◽  
Yankui Wang
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
High Angle ◽  
High Angle Of Attack

Strakes Effects on Asymmetric Flow Over a Blunt-Nosed Slender Body at a High Angle of Attack

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
Qihang Yuan ◽  
Yankui Wang ◽  
Zhongyang Qi
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
Axial Position ◽  
High Angle ◽  
Asymmetric Flow ◽  
High Angle Of Attack ◽  
Side Force ◽  
Asymmetric Vortices ◽  
High Angles Of Attack ◽  
Blunt Nose

In general speaking, the missiles execute flight at high angles of attack in order to enhance their maneuverability. However, the inevitable side-force, which is caused by the asymmetric flow over these kinds of traditional slender body configurations with blunt nose at a high attack angle, induces the yawing or rolling deviation and the missiles will lose their predicted trajectory consequently. This study examines and diminishes the side-force induced by the inevitable asymmetric flow around this traditional slender body configuration with blunt nose at a high angle of attack (AoA = 50 deg). On one hand, the flow over a fixed blunt-nosed slender body model with strakes mounted at an axial position of x/D = 1.6–2.7 is investigated experimentally at α = 50 deg (D is the diameter of the model). On the other hand, the wingspan of the strakes is varied to investigate its effect on the leeward flow over the model. The Reynolds number is set at ReD = 1.54 × 105 based on D and incoming upstream velocity. The results verify that the formation of asymmetric vortices is hindered by the existence of strakes, and the strake-induced vortices develop symmetrically and contribute to the reduction in side-force of the model. In addition, the increase in strake wingspan reduces asymmetric characteristics of the vortex around the model and causes a significant decrease in side-force in each section measured. The strake with the 0.1D wingspan can reduce the sectional side-force to 25% of that in the condition without strakes.

Active flow control of bi-stable asymmetric vortices on a slender body by alternating synthetic jets

2017 ◽  
Vol 232 (13) ◽  
pp. 2477-2488
Author(s):  
Qite Wang ◽  
Keming Cheng ◽  
Yunsong Gu ◽  
Wei Zuo
Keyword(s):  
Angle Of Attack ◽  
Stable State ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Slender Body ◽  
Symmetric Distribution ◽  
High Angle ◽  
Symmetric State ◽  
High Angle Of Attack ◽  
Control Frequency

A synthetic jet actuator with double nozzles is developed to control the leeward vortices behind the slender body at a high angle of attack. Periodic alternating disturbance at the nose tip of the slender body is continuously provided by the alternating synthetic jets. A series of experiments is conducted in a low speed and low turbulence wind tunnel. The results show that the alternating synthetic jets at the nose tip can achieve a suitable control effect in which the lateral force is eliminated. For a very high angle of attack, the leeward vortices behind the slender body are in the inherently bi-stable state; in this state, the symmetric distribution formation by the leeward vortices is nearly impossible. However, the alternating disturbance of the nose tip can break the bi-stable state and transform it into other two states, which are the unsteady switched state of the leeward vortices and the quasi-steady symmetric state. Varying the control frequency significantly affects the state of the leeward vortex. In the range of the lower control frequency, the leeward vortices switch back and forth and follow the cycle of the alternating disturbance at the nose tip. In the range of the higher control frequency, the leeward vortices are in a stable symmetric distribution state. As the alternating disturbance frequency increases from lower to higher, the switched amplitude of the leeward vortices decreases and the unsteady switched state of the leeward vortices gradually changes to the quasi-steady symmetric state. This amplitude reduction occurs because the position of the leeward vortices is very sensitive to the alternating disturbance of the nose tip and is related to the inertia effect of the fluid.

High Angle-of-Attack Aerodynamics on a Slender Body with a Jet Plume

1975 ◽  
Vol 12 (1) ◽  
pp. 12-16 ◽  
Author(s):  
R. C. NELSON ◽  
E. L. FLEEMAN
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
High Angle ◽  
High Angle Of Attack

Effect of Wire Trips on the Flow over Slender Body at High Angle of Attack

2007 ◽  
pp. 257-260
Author(s):  
Y. Chen ◽  
X. Y. Deng ◽  
Y. K. Wang
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
High Angle ◽  
High Angle Of Attack

scholarly journals Nose micro-blowing for asymmetric vortices control on blunt-nose slender body at high angle of attack

2017 ◽  
Vol 7 (6) ◽  
pp. 351-356 ◽  
Author(s):  
Lei Wang ◽  
Yankui Wang ◽  
Zhongyang Qi
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
High Angle ◽  
High Angle Of Attack ◽  
Asymmetric Vortices ◽  
Blunt Nose

scholarly journals Numerical Study of Vortex Flow Control on High-Angle-of-Attack Slender Body

2014 ◽  
Vol 12 (ists29) ◽  
pp. Pe_43-Pe_49 ◽  
Author(s):  
Masayuki SATOH ◽  
Hiroyuki NISHIDA ◽  
Taku NONOMURA
Keyword(s):  
Flow Control ◽  
Vortex Flow ◽  
Numerical Study ◽  
Angle Of Attack ◽  
Slender Body ◽  
High Angle ◽  
High Angle Of Attack

scholarly journals Preliminary Study on Aerodynamic Control of High-Angle-of-Attack Slender Body Using Blowing from Penetrating Flow Channels

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ayane Sato ◽  
Hiroyuki Nishida ◽  
Satoshi Nonaka
Keyword(s):  
Angle Of Attack ◽  
Surface Flow ◽  
The Body ◽  
Slender Body ◽  
High Angle ◽  
Control Effect ◽  
High Angle Of Attack ◽  
Separation Line ◽  
Flow Channels ◽  
Aerodynamic Control

The objective of this study is to experimentally verify a new aerodynamic control concept of a high-angle-of-attack slender body. In the concept, penetrating flow channels are installed to the apex of the slender body. The blowing or suction is generated at the channel exits in response to the surface pressure distribution. First, the effects of the flow channels on the aerodynamic characteristics are experimentally investigated in a low-speed wind tunnel. The result shows the Suction-Blowing type channel is the most effective because its control effect does not reduce even in higher mainstream flow velocity. The peak value of the side force and yawing moment can be reduced by up to 64% and 49%, respectively. In addition, visualization of the surface flow pattern by the oil flow method shows that the Suction-Blowing type channel makes not only the primary separation line on the body side but also the secondary separation line on the body back become symmetric.

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