• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.12
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• pp.986-993
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• 2018

Lateral thrust jet has better maneuverability performance than the control surface like the conventional fin for attitude control or orbital transition of guided weapons. However, in the supersonic region, a jet interaction flow occurs due to the lateral thrust jet during flight, and a complicated flow structure is exhibited by the interaction of the shock wave, boundary layer flow, and the vortex flow. Especially, hit-to-kill interceptors require precise control and maneuvering, so it is necessary to analyze the effect of jet interaction flow. Conventional jet interaction analyses were performed under low altitude conditions, but there are not many cases in the case of medium altitude condition, which has different flow characteristics. In this study, jet interaction flow analysis is performed on the lateral jet controlled interceptor operating at medium altitude. Based on the results, the structural characteristics of the flow field and the changes of aerodynamic coefficient are analyzed.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.1
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• pp.8-15
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• 2004

Supersonic jets impinging on $60^{\cire}$ wedge were investigated to obtain fundamental design data for jet deflector It was of interest to study flow phenomena such as shock interaction and separation induced by shear layer. Experiments using supersonic cold flow system were conducted for Schlieren flow visualization and measurement of surface pressure. Numerical results were compared with the experimental results. The major parameters are underexpansion ratio, distance from nozzle to apex and design Mach number. Flow conditions were obtained for the wedge shock to attach on or detach from the wedge. The dominant feature of flow-field is shock pattern induced by the Interaction between the wedge shock and the barrel shock.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.1
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• pp.26-33
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• 2001

Thrust vector control system is control device which is mounted exit of the nozzle to generate pitch, yaw and roll directional force by deflecting flow direction of the supersonic jet from the nozzle. By obtaining control force, jetvane which is exposed in jet flow is working thermal and aerodynamic load. Axial thrust loss and side thrust is affected by shock patterns and interactions between jetvanes according to jetvane geometry and turning angle. In this study, we designed 6 types of jetvane to evaluate pitch, yaw and roll characteristics of ietvane in supersonic flow, and perform the cold flow test in range of turning angles of jetvanes between $0^{\cire}$ and $25^{\cire}$ by $5^{\cire}$ respectively. Also, calculation is going side by side to analyse flow interaction. Results show that there is no interactions between jetvanes upto turning angle 20$^{\circ}$, chord and lead length ratio is very important parameter to aerodynamic performance and maximum thrust loss is appeard to 17% of axial thrust in roll directional control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.7
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• pp.26-31
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• 2003

In this paper, supersonic jets impinging on axisymmetric cone were investigated to obtain fundamental design data for jet deflector case of example being VTOL/STOL or rocket launch. It was of interest to study flow phenomena such as shock interactions and separation induced by shear layer. Experiments were conducted to obtain schlieren flow visualization and measurement of surface pressure. Numerical results are compared with the experimental result. The dominant feature of the flow is the shock pattern induced by the interaction between the cone shock and the barrel shock. This pattern can take a wide variety of forms depending on the structure of the free jet and strongly influences the form of the surface pressure distributions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.3
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• pp.187-194
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• 2020

In this study, computational analyses are carried out to investigate the interference flows and the aerodynamic characteristics of a hit-to-kill intercepter due to lateral jets at medium altitude. In addition, the analyses are performed for air and multi-species gas used in the side jet. The results indicate that the position of the barrel shock are shifted upstream and the structure of the shock wave are changed for the multi-species jet when compared to the air jet. As a result, the high pressure region with multi-species jet moves forward and the pitching moment is higher under the same flow condition. Moreover, the inclusion of high temperature effects makes drastic changes in pressure distribution. The jet width is much bigger, and the jet diffuses over wider range in medium altitude than in low altitude, because of the low density of the freestream.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.82.2-82.2
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• 2005

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.34-41
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• 2012

Thrust vector control system is a control device which is mounted on the exit of the nozzle to generate pitch, yaw and roll directional force by deflecting flow direction of the supersonic jet from the nozzle. Thermal and aerodynamic loads are acting on the surface of jet vane when it is exposed to the jet flow. Axial thrust loss and side thrust loss are affected by shock patterns and interactions between jet-vanes which varies with jet-vane geometry and turning angle. In this research, the performance estimation using the numerical simulation analysis of the nozzle is given and the investigation of the flow visualization and aerodynamic performance with the enforced power to the vane is taken.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.18-18
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• 1998

평판에 충돌하는 초음속 세트에 관한 연구는 수직/단거리 이·착륙기의 발진, 미사일 발사시스템, 다단계 로켓 분리 등 실제적인 분야에 응용되고 있으며 고온의 충돌제트와 화염에 의한 가열문제와 관련된 산입분야에서도 많은 연구가 이루어지고 있다. 과소팽창하는 초음속 제트가 평판에 충돌할 때 Barrel shock, exhaust gas boundary, Mach disk, contact surface, reflected shock, plate shock, stagnation bubble 등 매우 복잡한 유동 구조가 표면에 나타나는데 이것은 평판으로부터 반사된 shock과 free jet의 충격파 구조 사이에서의 상호간섭 때문이다. 노즐로부터 방출되는 고속, 고온가스가 주변 장비 등에 부딪힐 때 발생하는 이러한 복잡한 간섭현상의 연구는 관련 주변장비 설계 및 상황예측에 필수적인 자료를 제공하며 이해를 도와준다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.32-32
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• 1999

초음속 과소 팽창 제트가 경사진 평판에 충돌을 하게 되면 평판의 표면과 노즐출구에서 팽창된 자유제트(Free jet)와의 상호 간섭으로 인해 매우 복잡한 유동 구조가 형성된다. 예를 들면, 수직평판에서 발생되는 판 충격파(Plate shock)는 경사평판에서는 Upper plate shock, Lower plate shock, Intermediate plate shock과 같이 여러 형태로 발생되어 평판에서의 압력분포에 있어 수직일 경우와 다소 다른 경향을 보여준다. 본 연구의 주요 목적은 평판의 경사각을 변화시킬 때 평판 표면에서의 복잡한 유동 현상을 이해하는데 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.84-91
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• 2002

Thrust vector characteristics of jet vanes installed in a shroud are very unique and much more complicated than those of the jet vane acting without any shroud by the fact of additional physical phenomena. The fluid dynamic interferences induced by jet vanes and shroud as well as jet vane's aerodynamic performance are investigated to characterize thrust vector control by semi-empirical model, three dimensional numerical analysis including real complex geometry, and ground firing test of real motors.