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Towards full aircraft airframe noise prediction: lattice boltzmann simulations
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Khorrami, Mehdi R. Casalino, Damiano Fares, Ehab |
| Copyright Year | 2014 |
| Description | Computational results for an 18%-scale, semi-span Gulfstream aircraft model are presented. Exa Corporation's lattice Boltzmann PowerFLOW(trademark) solver was used to perform time-dependent simulations of the flow field associated with this high-fidelity aircraft model. The simulations were obtained for free-air at a Mach number of 0.2 with the flap deflected at 39 deg (landing configuration). We focused on accurately predicting the prominent noise sources at the flap tips and main landing gear for the two baseline configurations, namely, landing flap setting without and with gear deployed. Capitalizing on the inherently transient nature of the lattice Boltzmann formulation, the complex time-dependent flow features associated with the flap were resolved very accurately and efficiently. To properly simulate the noise sources over a broad frequency range, the tailored grid was very dense near the flap inboard and outboard tips. Extensive comparison of the computed time-averaged and unsteady surface pressures with wind tunnel measurements showed excellent agreement for the global aerodynamic characteristics and the local flow field at the flap inboard and outboard tips and the main landing gear. In particular, the computed fluctuating surface pressure field for the flap agreed well with the measurements in both amplitude and frequency content, indicating that the prominent airframe noise sources at the tips were captured successfully. Gear-flap interaction effects were remarkably well predicted and were shown to affect only the inboard flap tip, altering the steady and unsteady pressure fields in that region. The simulated farfield noise spectra for both baseline configurations, obtained using a Ffowcs-Williams and Hawkings acoustic analogy approach, were shown to be in close agreement with measured values. |
| File Size | 4130031 |
| Page Count | 35 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20150000544 |
| Archival Resource Key | ark:/13960/t9f52p388 |
| Language | English |
| Publisher Date | 2014-06-16 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Design, Testing And Performance Acoustics Deflection Computerized Simulation Kelvin-helmholtz Instability Aircraft Models Navier-stokes Equation Large Eddy Simulation Ffowcs Williams-hawkings Equation Airframes Aircraft Noise Semispan Models Wind Tunnel Tests Aircraft Configurations Nasa Programs Power Spectra Interactional Aerodynamics Boltzmann Distribution Pressure Distribution Aerodynamic Noise Landing Gear Sound Fields Contours Pressure Measurement Computational Grids Wing Flaps Aeroacoustics Aerodynamic Characteristics Noise Prediction Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
