• Title/Summary/Keyword: UCAV(Unmanned Combat Aerial Vehicle)

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Analysis of Flow and Infrared Signature Characteristics according to UCAV Nozzle Shape (무인전투기 배기구 형상에 따른 유동 및 적외선 신호 특성 분석)

  • Noh, Sooyoung;Bae, Ji-Yeul;Kim, Jihyuk;Nam, Juyeong;Jo, Hana;Cho, Hyung Hee
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.5
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    • pp.27-35
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    • 2019
  • Stealth technology is a technique to avoid detection from detectors such as radar and infrared seekers. In particular, detection by infrared signature is more threatening because infrared missiles detect heat from the aircraft itself. Therefore, infrared stealth technology is essential for ensuring the survival of aircraft and unmanned combat aerial vehicles (UCAV). In this study, we analyzed aerodynamic and infrared stealth performance in relation to UCAV nozzle design. Based on simulation results, a double serpentine nozzle was effective in reducing the infrared signature because it could shield high-temperature components in the engine. In addition, we observed that the infrared signature was reduced at the turning position of the duct located at the rear part of the double serpentine nozzle.

Design of an Autonomous Air Combat Guidance Law using a Virtual Pursuit Point for UCAV (무인전투기를 위한 가상 추적점 기반 자율 공중 교전 유도 법칙 설계)

  • You, Dong-Il;Shim, Hyunchul
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.3
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    • pp.199-212
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    • 2014
  • This paper describes an autonomous air combat guidance law using a Virtual Pursuit Point (VPP) in one-on-one close engagement for Unmanned Combat Aerial Vehicle (UCAV). The VPPs that consist of virtual lag and lead points are introduced to carry out tactical combat maneuvers. The VPPs are generated based on fighter's aerodynamic performance and Basic Fighter Maneuver (BFM)'s turn circle, total energy and weapon characteristics. The UCAV determines a single VPP and executes pursuit maneuvers based on a smoothing function which evaluates probabilities of the pursuit types for switching maneuvers with given combat states. The proposed law is demonstrated by high-fidelity real-time combat simulation using commercial fighter model and X-Plane simulator.

Analysis of Physical Combat Power for Unmanned Combat Aerial Vehicle (무인전투기 물리적 전투력 분석)

  • Min, Seungsik;Oh, Kyungwon
    • Journal of Aerospace System Engineering
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    • v.11 no.6
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    • pp.50-55
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    • 2017
  • The objective of this study was to use the Lanchester equation to predict the outcome of our engagement between our unmanned aerial vehicle (UAV) (Blue Group) and enemy UAV (Red Group). Lanchester's law states that the power of corps is proportional to the number of combatants. A second law states that the power of corps is proportional to the square of the number of combatants. The first law is a suitable law for guerrilla warfare while the second law is known as the law suitable for all-out war. Therefore, the second law is commonly used. The second law of Lanchester's was used in this study to predict engagement results. We estimated the battle loss rate value to win the battle as well as the required power number. We also predicted power number to make the damage of our group less than one. The battle loss rate to reliably receive victory when the enemy's UAV and the ally's UAV are equal in number of combat units must be 1: 1.5 or more.

Technical Survey on the Classification and Characteristics of UAV's Power Plant (UAV 추진기관의 종류 및 특성에 관한 기술적 고찰)

  • Lee, Dong-Hun;Paeng, Ki-Suk;Kim, Yu-Il;Park, Boo-Min;Choi, Seong-Man;Huh, Hwan-Il
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.3
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    • pp.79-86
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    • 2010
  • The characteristics and classification of UAV power plants were studied. The energy source for electric generation and power source for internal combustion engine for UAVs were compared. The advantage and drawbacks of power plants were analyzed respectively and the performance demand condition was suggested for next generation UAV power plant finally.

A Tailless UAV Multidisciplinary Design Optimization Using Global Variable Fidelity Modeling

  • Tyan, Maxim;Nguyen, Nhu Van;Lee, Jae-Woo
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.4
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    • pp.662-674
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    • 2017
  • This paper describes the multidisciplinary design optimization (MDO) process of a tailless unmanned combat aerial vehicle (UCAV) using global variable fidelity aerodynamic analysis. The developed tailless UAV design framework combines multiple disciplines that are based on low-fidelity and empirical analysis methods. An automated high-fidelity aerodynamic analysis is efficiently integrated into the MDO framework. Global variable fidelity modeling algorithm manages the use of the high-fidelity analysis to enhance the overall accuracy of the MDO by providing the initial sampling of the design space with iterative refinement of the approximation model in the neighborhood of the optimum solution. A design formulation was established considering a specific aerodynamic, stability and control design features of a tailless aircraft configuration with a UCAV specific mission profile. Design optimization problems with low-fidelity and variable fidelity analyses were successfully solved. The objective function improvement is 14.5% and 15.9% with low and variable fidelity optimization respectively. Results also indicate that low-fidelity analysis overestimates the value of lift-to-drag ratio by 3-5%, while the variable fidelity results are equal to the high-fidelity analysis results by algorithm definition.

Effects of IR Reduction Design on RCS of UCAV (IR 저감 설계가 무인전투기의 RCS에 미치는 영향)

  • Song, Dong-Geon;Yang, Byeong-Ju;Myong, Rho-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.4
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    • pp.297-305
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    • 2018
  • The role of UCAV is to carry out various missions in hostile situations such as penetration and attack on the enemy territory. To this end, application of RF stealth technology is indispensable so as not to be caught by enemy radar. The X-47B UCAV with blended wing body configuration is a representative aircraft in which modern RCS reduction schemes are heavily applied. In this study, a model UCAV was first designed based on the X-47B platform and then an extensive RCS analysis was conducted to the model UCAV in the high-frequency regime using the Ray Launching Geometrical Optics (RL-GO) method. In particular, the effects of configuration of UCAV considering IR reduction on RCS were investigated. Finally, the effects of RAM optimized for the air intake of the model UCAV were analyzed.

Numerical Analysis of Nozzle Plume Flow-Fields at Various Flight Conditions for Infrared Signature Investigation (IR 신호 분석을 위한 비행 조건에 따른 노즐 열유동장 해석)

  • Chun, S.H.;Yang, Y.R.;Moon, H.;Kim, J.Y.;Myong, R.S.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.601-604
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    • 2011
  • Plume flow-fields of aircraft nozzles are numerically investigated at various flight conditions for infrared signature analysis. A mission profile of subsonic unmanned combat aerial vehicle is considered for the requirement of each mission, associated engine and nozzles are selected through a performance analysis. Numerical results of nozzle plume flow-fields using a CFD code are analyzed in terms of thrust, maximum temperature. It is shown that maximum temperature increase for lower altitude and higher Mach number.

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COMPUTATIONAL INVESTIGATION OF NOZZLE FLOWFIELDS AT VARIOUS FLIGHT CONDITIONS FOR AIRCRAFT INFRARED SIGNATURE ANALYSIS (항공기 IR 신호 분석을 위한 다양한 비행 조건에서의 노즐 열유동장 해석)

  • Chun, S.H.;Yang, Y.R.;Moon, H.;Myong, R.S.;Cho, T.H.
    • Journal of computational fluids engineering
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    • v.16 no.3
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    • pp.15-21
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    • 2011
  • Aerothermodynamic flowfields of aircraft engine nozzles are computationally investigated at various flight conditions for infrared signature analysis. A mission profile of subsonic unmanned combat aerial vehicle is considered for the case study and associated engine and nozzles are selected through a performance analysis. Computational results of nozzle and plume flowfields using a density-based CFD code are analyzed in terms of thrust, maximum temperature, length and optical thickness of plume. It is shown that maximum temperature, length, and optical thickness of nozzle plume increase for lower altitude and higher Mach number.

Investigation of IR Survivability of Unmanned Combat Aerial Vehicle against Surface-to-Air Missiles (무인전투기의 지대공 미사일에 대한 IR 생존성 분석)

  • Lee, Ji-Hyun;Lee, Hyun-Jin;Myong, Rho-Shin;Choi, Seong-Man;Kim, Won-Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.12
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    • pp.1084-1093
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    • 2017
  • As the survivability of an aircraft in the battlefield becomes a critical issue, there is a growing need to improve the survivability of the aircraft. In this study, the survivability of an UCAV associated with plume IR signature was investigated. In order to analyze the survivability of the aircraft, the lock-on range and the lethal envelope, defined as the IR detection distance of the aircraft and the range of shooting down by the missile, respectively, were first introduced. Further, a method to calculate the lethal envelope for the scenario of surface-to-air missiles including the vertical plane was developed. The study confirmed that the red zone of an UCAV shows a substantial difference in the zone size as well as the characteristics in the upward and downward directions.

Effects of Wing Twist on Longitudinal Stability of BWB UCAV (날개의 비틀림이 동체-날개 융합익형 무인전투기의 종안정성에 미치는 영향에 대한 연구)

  • Ban, Seokhyun;Lee, Jihyeong;Kim, Sangwook;Cho, Jinsoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.1
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    • pp.1-9
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    • 2018
  • Lambda wing type Unmanned Combat Aerial Vehicle(UCAV) which adopts Blended Wing Body(BWB) has relatively less drag and more stealth performance than conventional aircraft. However, Pitching moment is rapidly increased at a specific angle of attack affected by leading edge vortex due to leading edge sweep angle. Wind tunnel testing and numerical analysis were carried out with UCAV 1303 configuration on condition of 50 m/s of flow velocity, $-4^{\circ}{\sim}28^{\circ}$ of the range of angle-of-attack. The effect of wing twist for longitudinal stability at the various angles of attack was verified in this study. When negative twist is applied on the wing, Pitch-break was onset at higher angle of attack due to delayed flow separation on outboard of the wing. On the other hand, pitch-break was onset at lower angle of attack and lift-to-drag ratio was increased when positive twist is applied on the wing.