• Title/Summary/Keyword: 편향각

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동축류 이차유동 분사를 이용한 추력 벡터 제어 방법에서 코안다 플랩의 형상에 따른 작동 특성 연구

  • Kim, Ju-Hyeon
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.537-540
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    • 2016
  • 유체역학적 추력 방향 제어(Fluidic Thrust Vector Control) 방법 중 하나인 동축류 제어 유동 분사를 이용한 추력 방향 제어(Co-flow Thrust Vector Control)의 작동 특성에 대해서 연구하였다. 이 제어 방법은 점성 유동이 벽면에 부착되어 흐르는 코안다 효과(Coanda Effect)를 이용하여 주 유동을 편향 시키는 방법으로서 그 편향각은 이러한 제어 유동 노즐 출구의 플랩 형상에 영향을 받는 것으로 알려져 있다. 이 연구에서는 출구 플랩 형상을 여러 가지로 바꾸어 가며 주 유동의 전압력 300kPa일 때 제어 유동의 편향각이 포화되는 제어유동의 전압력을 측정하였다. 그 결과 쐐기형 플랩의 각도가 증가할수록 포화 영역에서의 편향각은 증가하며 그 각은 플랩의 각도와 일치한다. 그러나 각도가 증가할수록 제어 유동이 플랩의 벽면을 지나면서 팽창파에 의해 가속되어 충격파을 발생시키게 되고 이 충격파는 주 유동에게까지 전파되어 주 유동 제트의 속도를 감소시킨다.

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Compressive Characteristics of Composites According to the Micro-structure and Stacking angle (직조구조차이와 적층각의 변화에 따른 섬유강화복합재료의 압축특성)

  • Yoo, Seong-Hwan;Park, Seok-Won;Chang, Seung-Hwan
    • Composites Research
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    • v.22 no.1
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    • pp.15-21
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    • 2009
  • In this paper, static compressive test and compression-compression fatigue test of carbon/epoxy composites which have different micro-structures were carried out with respect to the bias angle. In order to find out the effect of the micro-structure of the fabric composite on compressive characteristics the specimens made of UD carbon/epoxy composite comprising the same fiber and matrix system as the fabric composite were also prepared. The compressive strength and modulus were measured and these values were used to develop a semi-empirical formula for predicting compressive strength of the fabric composite with bias angles. The fatigue behavior of the fabric composite with respect to the bias angle variation was also investigated.

Impact Angle Control with Time Varying Continuous Biased PNG for Non-maneuvering Target (시변 연속적 편향 비례항법 유도법칙을 이용한 이동표적의 충돌각 제어)

  • Park, Jang-Seong;Kwon, Hyuck-Hoon;Park, Sang-Hyuck;Kim, Yoon-Young;Park, Bong-Gyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.9
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    • pp.742-751
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    • 2018
  • In this paper, we propose a time varying biased proportional navigation guidance law that controls the impact angle under Field-of-View(FOV) and the acceleration limit of the missile. The proposed law is composed of three stages in consideration of the FOV limitation. Since the bias directly affects the acceleration at each stage, the final bias value of the previous stage becomes the initial bias value of the next stage when the stage is switched. In addition, the impact angles were controlled by judging whether impact angles were reached in consideration of engagement conditions and physical constraints.

A Theoretical Study for the Thermal Diffusivity Measurement Using Photothermal Deflection Scheme (광열편향법을 이용한 열확산계수 결정에 대한 이론적 연구)

  • 전필수;이은호;유재석;목재균;최강윤
    • Journal of Energy Engineering
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    • v.10 no.1
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    • pp.63-70
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    • 2001
  • 재료의 열확산계수를 비접촉적인 방법으로 구하기 위하여 광열편향법에 대한 3차원 모델을 해석하였다. 이 방법은 가열빔이 재료에 광학적으로 흡수될 때 검사빔의 초기궤적이 시편과 시편주의 매질의 온도상승으로 인하여 나타나는 굴절지수의 구배에 의하여 검사빔이 편향되는 원리를 이용하는 것이다. 기존의 연구에서는 주로 가열빔과 검사빔의 상대거리를 변화시키면서 편향의 위상각을 측정하여 열확산계수를 결정하였다. 하지만 본 연구에서는 고정된 상대거리에서 가열빔의 변조주파수를 변화시키면서 편향의 위상각을 계산하여 열확산계수를 구할 수 있는 관계식을 제시하였다. 본 연구에서 제시한 열확산계수 결정 방법은 다른 방법에 비하여 실험과 해석이 간단하고 비교적 측정하기가 어려운 상대거리에 영향을 받지 않는 방법이다.

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Fabrication of deflector integrated laser diodes and light deflection (광 편향기 집적 레이저 다이오드의 제작 및 광의 편향)

  • 김강호;권오기;김종회;김현수;심은덕;오광룡;김석원
    • Korean Journal of Optics and Photonics
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    • v.15 no.2
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    • pp.171-176
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    • 2004
  • A light deflector integrated laser diode(LD) was fabricated and the characteristics of LD and ourput beam deflection as a function of deflector injection current were measured. To integrate the deflector with LD, a passive waveguide was integrated with the LD and a triangular-type light deflector was fabricated on the upper clad of the passive waveguide section. Light deflection from the fabricated light deflector is controlled by the effective refractive index variation induced by carrier injection. To characterize the effect of the deflector injection current, threshold current, slope efficiency, and output beam spectrum were measured as a function of deflector injection current. From these measured data, the increment in the threshold current and the decrement of the slope efficiency were observed. However, the output beam spectrum was not affected by the deflector. The Beam Propagation Method(BPM) was used to simulate the proposed device and the light deflection was measured by the far-field pattern of the output beam as a function of the deflector injection current. In the fabricated deflector integrated LD, the deflection angle of 1.9$^{\circ}$ at the injection current of 15 ㎃ was obtained.

Experimental Study of the Thrust Vectoring Characteristics in a Two-Dimensional Convergent-Divergent Nozzle (2차원 축소확대노즐의 추력편향특성 실험연구)

  • Yu, Du Whan;Choi, Seong Man;Oh, Seong Hwan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.2
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    • pp.84-93
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    • 2013
  • Stealthy, high maneuverability and super cruise abilities are required for the next generation fighter and unmanned aircraft. Thrust vector control technique currently come into use to meet these requirements. In this experimental study, axial and pitch thrust were measured and Schlieren visualization were carried out using the scaled two dimensional thrust vector nozzles under various pitch deflection angle, pitch flap length and height. From the study, we could get the supersonic flow characteristics and draw an optimum geometric configuration of the two dimensional thrust vector nozzle.

Performance Test of a Jet vane type Thrust Vector Control System (제트 베인형 추력편향장치의 성능시험)

  • 신완순;이정민;이택상;박종호;김윤곤;이방업
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.4
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    • pp.75-82
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    • 1999
  • Theoretical analysis and performance test of Jet vane type Thrust Vector Control(TVC) were conducted using supersonic cold-flow system. The use of TVC Systems an in particular jet vanes, are currently being researched for use in air launch, ship launch, underwater launch and high altitude maneuvering of tactical missiles and rockets. The necessity to generate control forces to rapidly change the course of the missile is frequently required when traditional, exterior aerodynamic surfaces are unable to produce these forces, when the flow over the control surface is insufficient. This situation can occur at launch, or high angles of attack of the control surfaces. Jet vanes peformed well at all altitudes and environmental conditions, and jet vanes are extremely effective at deflection angles up to as high as $30^{\circ}$, make them ideal for the launch and maneuver applications. In this study, performance test of supersonic cold-flow system and visualization of supersonic jet was conducted, and shape and deflection angle effect of two types of jet vanes are investigated.

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Numerical Study of the Thrust Vectoring Characteristics in a Two-Dimensional Convergent Divergent Nozzle (2차원 축소확대노즐의 추력편향특성 수치해석연구)

  • Kang, Hyung Seok;Choi, Seong Man;Oh, Seong Hwan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.2
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    • pp.94-104
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    • 2013
  • A numerical analysis has been conducted to determine the pitch thrust vectoring characteristics of a two-dimensional convergent divergent exhaust nozzle for supersonic aircraft application. The numerical analysis was done by using Fluent and verified by the experimental test results. Analysis was performed with pitch angle of $0^{\circ}$ and $20^{\circ}$ each at the ambient temperature condition. To see the effect of a ratio of pitch flap length and pitch flap height, the ratio was varied from 0.5 to 2.5. The numerical analysis shows that pitch thrust is changed greatly with pitch flap length. The big difference of the pitch thrust with pitch flap length is due to the shock interactions in the nozzle.

The Effect of Bias and Shear Angles on Compressive Characteristics of Carbon/Epoxy Plain Weave Fabrics (편향각과 전단각이 탄소섬유/에폭시 평직 복합재료의 압축특성에 미치는 영향)

  • Kim Sung-Jip;Chang Seung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.7 s.250
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    • pp.857-864
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    • 2006
  • Various compressive specimens were fabricated using autoclave do-gassing moulding to find out the compressive characteristics of the carbon/epoxy plain weave fabric composites with respect to the bias and shear angles. The stacking angles of the bias specimens are $[0]_{10T,}\;[3]_{10T,}\;[6]_{10T,}\;[9]_{10T,}\;[12]_{10T,}\;[15]_{10T,}\;[30]_{10T,}\;[45]_{10T}$ and those of the sheared specimens are $[{\pm}37]_{10T,}\;[{\pm}32]_{10T,}\;[{\pm}28]_{10T,}\;[{\pm}22]_{10T,}$ respectively. In order to verify the effect of micro-tow structures on compressive strength and modulus of the composites, compressive test specimens of uni-directional carbon/epoxy composites with the same materials and the same stacking conditions were fabricated. The modulus and strength of both types of composite specimens were compared with the prediction results based on the CLPT and a proposed strength formula. The tow deformation and fracture modes were investigated by microscopic observation.

Investigation of the 2D Convergent-Divergent Thrust Vectoring Nozzle (2D 추력편향 노즐 성능 및 유동 해석)

  • Kim, Yoon-Hee;Choi, Seong-Man;Chang, Hyun-Soo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.483-486
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    • 2009
  • An investigation of the thrust vectoring nozzle which can be applied to the supersonic variable exhaust system was performed. The maximum mach number of the model aircraft is 1.8 and mission radius is about 400Nm. The cycle analysis are performed at each operating regime of the aircraft and the specifications of the thrust vectoring nozzle were developed. Based upon the requirement of the thrust vectoring nozzle, two dimensional thrust vectoring nozzle were designed and flow analysis was conducted by deflection of the pitch and yaw angle.

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