• Title/Summary/Keyword: Dispersion-relation-preserving Method

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Numerical Study of Sound Generation Mechanism by a Blast Wave (폭발파에 의한 음향파 생성 메커니즘의 수치적 연구)

  • Bin, Jong-Hoon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.10
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    • pp.1053-1061
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    • 2009
  • The goal of this paper is to investigate the generation characteristics of the main impulsive noise sources generated by the supersonic flow discharging from a muzzle. For this, this paper investigates two fundamental mechanisms to sound generation in shocked flows: shock motion and shock deformation. Shock motion is modeled numerically by examining the interaction of a sound wave with a shock. The numerical approach is validated by comparison with results obtained by linear theory for a small disturbance case. Shock deformations are modeled numerically by examining the interaction of a vortex ring with a blast wave. A numerical approach of a dispersion-relation-preserving(DRP) scheme is used to investigate the sound generation and propagation by their interactions in near-field.

A Numerical Study on Hydrodynamic Force Affecting the Vertical Wall of a Portable Water Storage Tank (자유수면의 출렁임이 이동형 소방용수 저장탱크의 수직 벽면에 미치는 동수력에 대한 수치해석)

  • Park, Jinsoo;So, Soohyun;Jang, Taek Soo
    • Fire Science and Engineering
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    • v.31 no.3
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    • pp.49-53
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    • 2017
  • In the present study, the hydrodynamic force acting on the vertical wall of a portable water storage tank is examined. A Dispersion Relation Preserving (DRP) method, proposed by Jang, is applied for simulating lapping waves and their impact on the wall. A meaningful investigation has been observed, which may be applied to the strength design for the portable water storage tank.

Numerical Investigation on the Mechanism of Mode Transition in Axi-symmetric Supersonic Jet Screech (축대칭 초음속 제트에서 스크리치 모드 전이현상의 수치적 연구)

  • Bin, Jong-Hoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.8
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    • pp.790-797
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    • 2010
  • Mode transition of the axi-symmetric screech tone in the low supersonic Mach number range from 1.0 to 1.20 is numerically analyzed. The axi-symmetric Navier-Stokes equations and the k-e turbulence model are solved in the cylindrical coordinate system. The dispersion-relation-preserving(DRP) scheme is applied for space discretization and the optimized four levels marching method are used for time integration. At low supersonic Mach numbers with an axi-symmetric A1 mode in the simulation, it is shown that acoustic propagation due to the nonlinear effects is seen in the lateral direction and the screech tone frequency is the same as the vortex passing frequency due to the generation of intense large-scale vortical motions.