Landing Gear Aerodynamic Noise Prediction Using Unstructured Grids

Aerodynamic noise from a landing gear in a uniform flow is computed using the Ffowcs Williams-Hawkings (FW-H) equation. The time accurate flow data on the integration surface is obtained using a finite volume low-order flow solver on an unstructured grid. The Ffowcs Williams-Hawkings equation is solved using surface integrals over the landing gear surface and over a permeable surface away from the landing gear. Two geometric configurations are tested in order to assess the impact of two lateral struts on the sound level and directivity in the far-field. Predictions from the Ffowcs Williams-Hawkings code are compared with direct calculations by the flow solver at several observer locations inside the computational domain. The permeable Ffowcs Williams-Hawkings surface predictions match those of the flow solver in the near-field. Far-field noise calculations coincide for both integration surfaces. The increase in drag observed between the two landing gear configurations is reflected in the sound pressure level and directivity mainly in the streamwise direction.

[1]  William H. Rae,et al.  Low-Speed Wind Tunnel Testing - second edition , 1984 .

[2]  I. Duff,et al.  Direct Methods for Sparse Matrices , 1987 .

[3]  F. Farassat,et al.  An Analytical Comparison of the Acoustic Analogy and Kirchhoff Formulation for Moving Surfaces , 1997 .

[4]  Mehdi R. Khorrami,et al.  Computational aeroacoustic analysis of slat trailing-edge flow , 1999 .

[5]  Lyle N. Long,et al.  Jet noise simulations for circular nozzles , 2000 .

[6]  Barry S. Lazos,et al.  Mean Flow Features Around the Inline Wheels of Four-Wheel Landing Gear , 2002 .

[7]  Lyle N. Long,et al.  Unsteady Separated Flow Simulations Using a Cluster of Workstations , 1999, PDPTA.

[8]  P. D. Francescantonio.  A NEW BOUNDARY INTEGRAL FORMULATION FOR THE PREDICTION OF SOUND RADIATION , 1997 .

[9]  Werner Dobrzynski,et al.  A European Study on Landing Gear Airframe Noise Sources , 2000 .

[10]  F. Farassat,et al.  Supersonic Quadrupole Noise Theory for High-Speed Helicopter Rotors , 1997 .

[11]  Lyle N. Long,et al.  Self-Scheduling Parallel Methods for Multiple Serial Codes with Application to WOPWOP , 2000 .

[12]  Yusuf Özyörük,et al.  A New Efficient Algorithm for Computational Aeroacoustics on Parallel Processors , 1996 .

[13]  Hanno H. Heller,et al.  Sound radiation from aircraft wheel-well/landing gear configurations , 1976 .

[14]  Hanno H. Heller,et al.  Sound Radiation from Aircraft Wheel-WelVLanding-Gear Configurations , 1977 .

[15]  William H. Rae,et al.  Low-Speed Wind Tunnel Testing , 1966 .

[16]  F. Farassat,et al.  The Uses and Abuses of the Acoustic Analogy in Helicopter Rotor Noise Prediction , 1987 .

[17]  Pierre Sagaut,et al.  On the radiated noise computed by large-eddy simulation , 2001 .

[18]  David P. Lockard,et al.  Simulation of acoustic scattering from a trailing edge , 1999 .

[19]  Ugo Piomelli,et al.  Large-eddy simulation: achievements and challenges , 1999 .

[20]  Werner Dobrzynski,et al.  Full-Scale Noise Testing on Airbus Landing Gears in the German-Dutch Wind Tunnel. , 1997 .

[21]  Lyle N. Long,et al.  Turbulent Flow and Aeroacoustics Simulations using a Clusters of Workstations , 2001 .

[22]  Lyle N. Long,et al.  AIRWAKE SIMULATIONS ON AN LPD 17 SHIP , 2001 .

[23]  M. Strelets.  Detached eddy simulation of massively separated flows , 2001 .

[24]  Lyle N. Long,et al.  AERODYNAMIC NOISE PREDICTION USING PARALLEL METHODS ON UNSTRUCTURED GRIDS , 2001 .

[25]  Rahul Sen,et al.  An experimental investigation of airframe noise using a model-scale Boeing 777 , 2001 .

[26]  D. Bushnell,et al.  Effects of Eddy Viscosity on Time Correlations in Large Eddy Simulation , 2001 .

[27]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .