Journal of the Korea Institute of Military Science and Technology (한국군사과학기술학회지)

The Korea Institute of Military Science and Technology (한국군사과학기술학회)
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Numerical Study about Initial Behavior of an Ejecting Projectile for Varying Flight Conditions

비행 조건 변화에 따른 사출 운동체의 초기 거동에 관한 수치적 연구

  • 조성민 (한국과학기술원 항공우주공학과) ;
  • 권오준 (한국과학기술원 항공우주공학과) ;
  • 권혁훈 (LIG넥스원(주) 유도무기수출개발단 2팀) ;
  • 강동기 (LIG넥스원(주) 유도무기수출개발단 2팀)
  • Received : 2019.03.06
  • Accepted : 2019.06.21
  • Published : 2019.08.05
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Abstract

In the present study, unsteady flows around a projectile ejected from an aircraft platform have been numerically investigated by using a three dimensional compressible RANS flow solver based on unstructured meshes. The relative motion between the platform and projectile was described by six degrees of freedom(6DOF) equations of motion with Euler angles and a chimera technique. Initial behavior of the projectile for varying conditions, such as roll and pitch-yaw command on the control surface of the projectile, flight Mach number, and platform pitch angle, was investigated. The ejection stability of the projectile was degraded as Mach number increases. In the transonic condition, the initial behavior of the projectile was found to be unstable as increase of platform pitch angle. By applying the command to control surfaces of the projectile, initial stability was highly enhanced. It was concluded that the proposed simulation data are useful for estimating the ejection behavior of a projectile in design phase.

Keywords

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Fig. 1. (a) unstructured overset meshes, and (b) surface mesh of the projectile

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Fig. 3. 6DOF analysis for varying flight mach number

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Fig. 4. Sectional pressure coefficient distributions for varying flight Mach number

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Fig. 5. Comparison of time trajectories for varying platform pitch angle at M = 0.6

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Fig. 6. 6DOF analysis for varying platform pitch angle at M = 0.6

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Fig. 7. Comparison of time trajectories for varying platform pitch angle at M = 0.8

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Fig. 8. 6DOF analysis for varying platform pitch angle at M = 0.8

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Fig. 9. Sectional pressure coefficient distributions for varying platform pitch angle at M = 0.8

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Fig. 10. Comparison of time trajectories for varying roll command angles

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Fig. 11. 6DOF analysis for varying roll command angles

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Fig. 12. Comparison of time trajectories for varying pitch-yaw command angles

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Fig. 13. 6DOF analysis for varying pitch-yaw command angles

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Fig. 2. Comparison of time trajectories for varying flight mach number

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