On numerical simulations of fore and aft noise radiation from turbofans

Özyörük, Yusuf
Long, L.N.
This paper discusses numerical simulations of fore and aft noise radiation from turbofan engines. Three different approaches are considered. These are based on the explicit solutions of the full Euler equations, Euler equations linearized about a nonuniform background flow, and the frequency space form of the linearized Euler equations with nonuniform flow, respectively. Issues related to the fan-face inflow and outflow boundary conditions are discussed, and results from the three methods are presented and compared. © 2003 by the authors.


Assessment of a frequency-domain linearised Euler solver for turbofan aft radiation predictions and comparison with measurements
Özyörük, Yusuf (2010-03-31)
This paper presents a frequency-domain computational aeroacoustics tool for predicting aft noise radiation through turbofan ducts and jets and its application to two realistic engine exhaust configurations which have been experimentally tested. The tool is based on the discretised axisymmetric form of the linearised Euler equations in conjunction with perfectly matched layer equations at the inlet and far-field boundaries using high-order finite differences. The resultant linear system of equations is inver...
Numerical prediction of aft radiation of turbofan tones through exhaust jets
Özyörük, Yusuf (2009-08-07)
This paper describes a numerical methodology for calculating tonal noise propagation and radiation through turbomachinery exhaust ducts, including non-uniform background jet flows. The numerical method is based on solution of the linearized Euler equations directly in the frequency domain, employing a direct, sparse matrix solver in parallel. Acoustic sources are introduced into the computational domain via the perfectly matched layer equations. Various test cases including propagation through infinite duct...
Numerical investigations of lateral jets for missile aerodynamics
Ağsarlıoğlu, Ekin; Albayrak, Kahraman; Department of Mechanical Engineering (2011)
In this thesis, effects of sonic lateral jets on aerodynamics of missiles and missilelike geometries are investigated numerically by commercial Computational Fluid Dynamics (CFD) software FLUENT. The study consists of two parts. In the first part, two generic missile-like geometries with lateral jets, of which experimental data are available in literature, are analyzed by the software for validation studies. As the result of this study, experimental data and CFD results are in good agreement with each other...
Numerical investigation of characteristics of pitch and roll damping coefficients for missile models
Kayabaşı, İskander; Kurtuluş, Dilek Funda; Department of Aerospace Engineering (2012)
In this thesis the characteristics of pitch and roll damping coefficients of missile models are investigated by using Computational Fluid Dynamics (CFD) techniques. Experimental data of NACA0012 airfoil, Basic Finner (BF) and Modified Basic Finner (MBF) models are used for validation and verification studies. Numerical computations are performed from subsonic to supersonic flow regimes. Grid refinement and turbulence model selection studies are conducted before starting the dynamic motion simulations. Numer...
Trajectory computation of small solid particles released and carried by flowfields of helicopters in forward flight
Pekel, Yusuf Okan; Özyörük, Yusuf; Department of Aerospace Engineering (2010)
In this thesis, trajectory computations of chaff particles ejected from a medium weight utility helicopter are performed using computational fluid dynamics. Since these chaff particles are ejected from a helicopter and carried by its flow field, it is necessary to compute and include the effects of the helicopter flow field in general and engine hot gases, main and tail rotor wakes in particular. The commercial code FLUENT is used for flow field and trajectory computations. Both main rotor and tail rotor ar...
Citation Formats
Y. Özyörük and L. N. Long, “On numerical simulations of fore and aft noise radiation from turbofans,” 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/68847.