Bibliographic citations
Yupa, R., (2021). Numerical study of jet-flap interaction noise and a procedure for designing thrust gates [Universidade Federal de Santa Catarina]. https://renati.sunedu.gob.pe/handle/sunedu/2229982https://repositorio.ufsc.br/handle/123456789/221310
Yupa, R., Numerical study of jet-flap interaction noise and a procedure for designing thrust gates []. BR: Universidade Federal de Santa Catarina; 2021. https://renati.sunedu.gob.pe/handle/sunedu/2229982https://repositorio.ufsc.br/handle/123456789/221310
@mastersthesis{renati/2372,
title = "Numerical study of jet-flap interaction noise and a procedure for designing thrust gates",
author = "Yupa Villanueva, Renatto Marcello",
publisher = "Universidade Federal de Santa Catarina",
year = "2021"
}
Jet-Flap Interaction (JFI) noise is caused by the proximity of the turbofan engine to airframe surfaces, occurring mainly at take-off and landing. Due to the increase in the size of turbofan engines for the next generation of aircraft, their proximity to the wing tends to increase, in order to maintain a minimum ground clearance. This, associated with the need to reduce the perceived noise by 65% for 2050, makes necessary studies on the JFI noise and strategies for its mitigation necessary. In this context, geometric modifications of the flap, known as thrust gates could be an alternative. In accordance with the industry needs, the present investigation aims to study JFI noise and its mitigation by fitted rectangular and concave thrust gates based on a quantitative criterion. To accomplish the objective, numerical simulations based on the Lattice Boltzmann Method (LBM), coupled with the Very Large Eddy Simulation (VLES) approach under subsonic conditions and using simplified wing-flap models were performed for Mach numbers 0.5 and 0.7 and flap angle inclinations 7°, 15° and 30°. Initially, a spatial grid independence study for a free jet and two installed jets (with and without thrust gate), considering Mach number 0.7 was conducted. A converged grid supported by a Grid Convergence Index (GCI) analysis for y+, boundary layer at the nozzle exit and OASPL was obtained. Then, considering the converged grid, the numerical model validation was performed, comparing the numerical results with measurements. The numerical results concerning the noise resulting from the JFI presented noise directivity, destructive interference, amplification and shielding, and presence of tones. In general terms, these effects were observed to be stronger with the presence of the flap and its deflection angle. In this sense, it was proposed a criterion for fitting rectangular and concave thrust gates based on mean gauge pressure computed at the bottom side of the flap considering Mach number 0.5 and 0.7 combined with flap angle inclinations 7° and 30°. Despite the criterion had shown to be more effective for rectangular thrust gates, important noise reductions were achieved using the concave ones. In a general assessment, the numerical method LBM-VLES proved to be quite efficient to predict the noise caused by the free and installed jets with and without thrust gates, as well as for the exhaustive analyses concerning JFI noise and its mitigation by fitted thrust gates developed in this work.
File | Description | Size | Format | |
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YupaVillanuevaRM.pdf Restricted Access | Disertación (abierta en repositorio de origen) | 8.35 MB | Adobe PDF | View/Open Request a copy |
Autorizacion.pdf Restricted Access | Autorización del registro | 294.4 kB | Adobe PDF | View/Open Request a copy |
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