TY - GEN

T1 - Numerical simulation of the hole-tone feedback cycle based on the discrete vortex method and the acoustic analogy

AU - Langthjem, Mikael A.

AU - Nakano, Masami

PY - 2003/1/1

Y1 - 2003/1/1

N2 - An axisymmetric numerical simulation approach to the holetone feedback problem is developed. It is based on the discrete vortex method and an 'acoustic analogy' representation of flow noise sources. The shear layer of the jet is represented by 'free' discrete vortex rings, and the jet nozzle and the end plate by bound vortex rings. A vortex ring is released from the nozzle at each time step in the simulation. The newly released vortex rings are disturbed by acoustic feedback. The simulated frequencies f follow the criterion L/u c+L/c0 = n/f where L is the gap length, uc is the shear layer convection velocity, C0 is the speed of sound, and n is a mode number (n = 1/2, 1, 3/2, . . .). This is in agreement with experimental observations. The numerical model also display mode shifts (jumps in the chosen value of n), as seen in experiments.

AB - An axisymmetric numerical simulation approach to the holetone feedback problem is developed. It is based on the discrete vortex method and an 'acoustic analogy' representation of flow noise sources. The shear layer of the jet is represented by 'free' discrete vortex rings, and the jet nozzle and the end plate by bound vortex rings. A vortex ring is released from the nozzle at each time step in the simulation. The newly released vortex rings are disturbed by acoustic feedback. The simulated frequencies f follow the criterion L/u c+L/c0 = n/f where L is the gap length, uc is the shear layer convection velocity, C0 is the speed of sound, and n is a mode number (n = 1/2, 1, 3/2, . . .). This is in agreement with experimental observations. The numerical model also display mode shifts (jumps in the chosen value of n), as seen in experiments.

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U2 - 10.1115/fedsm2003-45463

DO - 10.1115/fedsm2003-45463

M3 - Conference contribution

AN - SCOPUS:0346273654

SN - 0791836967

SN - 9780791836965

T3 - Proceedings of the ASME/JSME Joint Fluids Engineering Conference

SP - 33

EP - 40

BT - Proceedings of the 4th ASME/JSME Joint Fluids Engineering Conference

A2 - Ogut, A.

A2 - Tsuji, Y.

A2 - Kawahashi, M.

PB - American Society of Mechanical Engineers

T2 - 4th ASME/JSME Joint Fluids Engineering Conference

Y2 - 6 July 2003 through 10 July 2003

ER -