• Title/Summary/Keyword: Missile Datcom

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Application of Artificial Neural Network to Predict Aerodynamic Coefficients of the Nose Section of the Missiles (인공신경망 기반의 유도탄 노즈 공력계수 예측 연구)

  • Lee, Jeongyong;Lee, Bok Jik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.11
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    • pp.901-907
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    • 2021
  • The present study introduces an artificial neural network (ANN) that can predict the missile aerodynamic coefficients for various missile nose shapes and flow conditions such as Mach number and angle of attack. A semi-empirical missile aerodynamics code is utilized to generate a dataset comprised of the geometric description of the nose section of the missiles, flow conditions, and aerodynamic coefficients. Data normalization is performed during the data preprocessing step to improve the performance of the ANN. Dropout is used during the training phase to prevent overfitting. For the missile nose shape and flow conditions not included in the training dataset, the aerodynamic coefficients are predicted through ANN to verify the performance of the ANN. The result shows that not only the ANN predictions are very similar to the aerodynamic coefficients produced by the semi-empirical missile aerodynamics code, but also ANN can predict missile aerodynamic coefficients for the untrained nose section of the missile and flow conditions.

Analysis of Folding Wing Deployment with Aero and Restraint Effects (공기력 및 구속 효과를 고려한 접힘 날개 전개 성능 분석)

  • Kim, Seung-il
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.6
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    • pp.533-539
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    • 2015
  • Recently, guided missiles applies folding wings to save space. During wing deployment, aero force acting on wing effects significantly on deployment performance, usually aerodynamic coefficient are calculated by CFD analysis. However, Missile Datcom can calculates estimated aerodynamic coefficient very quickly by assuming wing deployment motions as dihedral angle of wing. If missile has external store, wings may need to be folded on top of each other. In this case, one of wing help or interrupt other wing deployment, locking effect. In this study, both effects were included on wing deployment performance analysis to criteria for wings locked condition and formulated wing deploy performance, and compared with wind tunnel test data. Analysis predicted vulnerable wind direction of wing deployment very well.

Analysis of the Aerodynamic Characteristics of Missile Configurations Using a Semi-Empirical Method (Semi-Empirical 기법을 이용한 미사일 형상의 공력특성 해석)

  • Han, Myung-Shin;Myong, Rho-Shin;Cho, Tae-Hwan;Hwang, Jong-Son;Park, Chan-Hyeok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.3
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    • pp.26-31
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    • 2005
  • An efficient estimation of the aerodynamic characteristics for missile configurations is essential in the preliminary stage of a missile design. In this study, a Missile DATCOM family code based on the semi-empirical method was utilized for this purpose. In order to check the accuracy and reliability of the code several test cases have been considered: subsonic flow with high angles of attack and supersonic flow with moderate angles of attack. It turned out that the code in general provides prediction in qualitative agreement with the experimental data and results by other works. Finally, the code was applied to a more complicated missile configuration with canard and freely spinning tail fin.

500 lbs-class Air-to-Surface Missile Design by Integration of Aerodynamics and RCS (공력해석과 RCS해석 통합 500 lbs급 공대지 미사일 최적설계)

  • Bae, Hyo-Gil;Lee, Kwang-Ki;Jeong, Jun-O;Sang, Dae-Kyu;Kwon, Jang-Hyuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.2
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    • pp.184-191
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    • 2012
  • Aerodynamic analysis(DATCOM) and radar cross section(RCS) analysis(POFACETS) were integrated for the air-to-surface missile concept design using a design framework. The missile geometry was defined based on the CAD(CATIA) for synchronizing the manufacturing with design processes. Aero/RCS analyses were linked with the CAD process under the ModelCenter framework in order to receive the geometry data automatically. The missile design baseline configuration was selected from ROC(requirement of capability). Then the RCS minimization was performed subject to thelargerthebetter constraint of the missile lift-to-drag ratio. This study demonstrated that various design strategies can be performed efficiently about many missile configurations using this design framework in the missile conceptual design phase.

A Comparison of Aerodynamic Prediction Methodologies for Missile Configurations (유도무기 형상의 공력 특성 예측 방법 비교)

  • Noh, Kyung-Ho;Kang, Donggi;Kim, Jaehyun;Kim, Young Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.11
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    • pp.755-762
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    • 2022
  • The wind tunnel test data for the missile configuration were compared with analysis results using various semi-empirical code and CFD analysis code. The three types of configurations were used for comparison including 2 types of main wing, inline and interdigitate configuration that the main wing and tail intersect. Additionally, it was confirmed that the vortex flow was accurately predicted by comparing the CFD analysis result with the flow visualization test result.

An External Shape Optimization Study to Maximize the Range of a Guided Missile in Atmospheric Flight (대기권을 비행하는 유도 미사일의 최대 사거리 구현을 위한 외형 형상 최적화 시스템 연구)

  • Yang, Young-Rok;Hu, Sang-Bum;Je, So-Yeong;Park, Chan-Woo;Myong, Rho-Shin;Cho, Tae-Hwan;Hwang, Ui-Chang;Je, Sang-Eon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.6
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    • pp.519-526
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    • 2009
  • This paper describes a research result of a external shape optimization study to maximize the range of the guided missile with canards and tailfins in atmospheric flight. For this purpose, the external shape optimization program which can enhance the range of a missile was developed, incorporated with the trajectory analysis and the optimization technique. In the trajectory analysis part, Missile DATCOM which utilizes the semi-empirical method was directly connected to the trajectory code to supply the aerodynamic coefficients efficiently at every time step. In the gliding flight trajectory after apogee, a maximum $C_L/C_D$ trim condition calculation module was attached under the assumption of the missile continuously flying at maximum $C_L/C_D$ condition. In the optimization part, a Response Surface Method(RSM) was adopted to reduce the computing time.

Adaptive Control Design for Missile using Neural Networks Augmentation of Existing Controller (기존제어기와 신경회로망의 혼합제어기법을 이용한 미사일 적응 제어기 설계)

  • Choi, Kwang-Chan;Sung, Jae-Min;Kim, Byoung-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.12
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    • pp.1218-1225
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    • 2008
  • This paper presents the design of a neural network based adaptive control for missile is presented. The application model is Exocet MM40, which is derived from missile DATCOM database. Acceleration of missile by tail Fin control cannot be controllable by DMI (Dynamic Model Inversion) directly because it is non-minimum phase system. So, the inner loop consists of DMI and NN (Neural Network) and the outer loop consists of PI controller. In order to satisfy the performances only with PI controller, it is necessary to do some additional process such as gain tuning and scheduling. In this paper, all flight area would be covered by just one PI gains without tuning and scheduling by applying mixture control technique of conventional controller and NN to the outer loop. Also, the simulation model is designed by considering non-minimum phase system and compared the performances to distinguish the validity of control law with conventional PI controller.

A Prediction Study on the Roll Lock-in Phenomena of Freely Spinning Tailfins (자유회전 테일핀의 Roll Lock-in 현상 예측 연구)

  • Yang, Young-Rok;Cho, Tae-Hwan;Myong, Rho-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.9
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    • pp.849-855
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    • 2010
  • This paper investigated the roll lock-in phenomena of a canard-controlled missile with freely spinning tailfins by applying Falanga's roll-rate equation. To confirm and validate the accuracy of the results of the roll-rate and roll lock-in prediction for freely spinning tailfins, the results were compared with Blair's wind tunnel test data. For calculation of the roll-rate of freely spinning tailfins, rolling moment coefficients of the tailfins were obtained from the wind tunnel test data and roll-damping coefficients were calculated by missile DATCOM. The roll-rate and roll lock-in of the freely spinning tailfins were calculated by applying these values to the roll-rate equation for freely spinning tailfins. The calculation results showed good agreement with the wind tunnel test data, and the roll lock-in could be anticipated as well.

Separation Analysis of a Store with Deployable Wings (날개 전개가 가능한 무장의 분리 특성해석)

  • Kim, Byeong-Kyoo;Kim, Sang-Jin;Kang, In-Mo;Kim, Myung-Seong;Lee, Seung-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.5
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    • pp.381-389
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    • 2007
  • 6-DOF simulation program is developed in order to increase the efficiency of the store separation analysis. This S/W is much faster than a method based on CFD(Computational Fluid Dynamics) technology, and allows the simulation of stores with fixed shape as well as with extensible wings, because it uses aerodynamic databases which are prepared beforehand. In this paper, aerodynamic databases of stores are obtained with MSAP(Multi-body Separation Analysis Program), and unsteady damping coefficients are modeled with Missile Datcom. These databases and the 6-DOF simulation program are used to predict the trajectory of an external store, while its wings are being deployed. The analysis results indicate that the safe separations of the store can be achieved not only with the wing fixed but with the wings being deployed.

Analysis of Aerodynamic Characteristics for Guided Gliding Type Ammunition Using Computational Analysis and Wind Tunnel Test (전산해석 및 풍동시험을 이용한 유도형 활공탄약의 공력해석)

  • Bang, Jae Won
    • Journal of the Korea Society for Simulation
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    • v.28 no.1
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    • pp.49-56
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    • 2019
  • In this study aerodynamic characteristics of guided gliding type ammunition were investigated by using a computational analysis and wind tunnel test. Missile DATCOM, a semi-empirical method, and a FLUENT, a computational fluid dynamics analysis program, were used for computational analysis. For a guided gliding type ammunition, aerodynamic characteristics were investigated by calculating lift force, drag force, pitching moment and etc. Aerodynamic characteristics of guided gliding type ammunition are completely different from those of conventional ammunition. The results obtained from the computer analysis are similar to those obtained from the wind tunnel test. Although the pitch moment values obtained by the semi-empirical method were slightly different from the wind tunnel test results, the overall computer analysis results showed trends and values similar to the test results. In this study, aerodynamic characteristics of guided gliding type ammunition were identified and it found that semi-empirical method can be applied to analyze the aerodynamic characteristic in the initial design of guided gliding ammunition.