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COBEM 2019
25th International Congress of Mechanical Engineering
INVESTIGATION OF JET-FLAP INTERACTION NOISE THROUGH NUMERICAL SIMULATIONS BASED ON THE LATTICE BOLTZMANN METHOD
Submission Author:
Renatto Yupa-Villanueva , SC , Peru
Co-Authors:
Renatto Yupa-Villanueva, GIL FELIX GRECO, José Rodrigues de Lima Neto Sirotto, Filipe Dutra da Silva, Cesar Deschamps
Presenter: Renatto Yupa-Villanueva
doi://10.26678/ABCM.COBEM2019.COB2019-1376
Abstract
One of the main sources of aircraft noise during takeoff condition is caused by the exhaust jet from the engine. Therefore, studies in this area have gained importance with the rise of stricter noise regulations. In this paper, a numerical analysis of a cold single-flow under both isolated and installed configurations were conducted. The flow conditions were, acoustic Mach number Ma = 0.7, freestream Mach number M∞ = 0 and jet temperature ratio to the ambient of TJ/T∞ = 0.95. The installed configuration considered a flapped plate with trailing edge (TE) placed at a distance X/DJ = 3.20 measured from the nozzle exit and at a radial distance H/DJ = 0.59 from the jet axis. Experimental tests were performed for polar angles 60°≤θ≤150° with ∆θ=10°, where 180° corresponds to the downstream direction of the jet nozzle. Numerical results were obtained using Very Large Eddy Simulations (VLES) based on the Lattice Boltzmann Method (LBM). The numerical far-field noise predictions were obtained through the permeable Ffowcs-Williams Hawkings (FWH) integral formulation. Grid resolution studies were carried out to assess numerical truncation error. The numerical results were then validated through comparisons with measurements of Sound Pressure Level (SPL) with differences around of 2.5 dB in 1/3 octave bands being observed at θ=90°. Low-frequency noise amplifications were predicted occurring at the unshielded and shielded sides of the installed case, being mainly dominant at the polar angles θ<90°. The installed configuration presented Overall Sound Pressure Levels about 6.5 dB and 9.5 dB higher in comparison to the isolated jet for both shielded and unshielded sides, respectively. Contours of SPL as function of St and polar angles showed higher noise levels in the low St range (St<0.68).
Keywords
jet noise, Jet-Flap Interaction, Lattice Boltzmann method
