Time-domain calculation of sound propagation in lined ducts with sheared flows

Date

2000-05-01

Author

Özyörük, Yusuf

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

260
views

0
downloads

A recent application of the time-domain equivalent of the classical acoustic impedance condition, i.e., the particle displacement continuity equation, to numerical simulations of a Bow-impedance tube in the time domain yielded reasonably good results with uniform mean flows. The present paper extends this application to include sheared mean-flow effects on sound propagation over acoustically treated walls. To assess the prediction improvements with sheared flows, especially at relatively high Mach numbers, numerical simulations of the NASA Langley Research Center flow-impedance tube are carried out at actual conditions. Calculations are realized fur mean-flow peak velocities as high as Mach 0.5 at various frequencies. Results are compared with those obtained with uniform mean Rows and experimental data. It is shown that solutions that were not attainable previously with uniform Rows at high Mach numbers can now be obtained with the help of the no-slip conditions of sheared background Rows at the wall.

Subject Keywords

Aerospace Engineering

URI

https://hdl.handle.net/11511/40644

Journal

AIAA JOURNAL

DOI

https://doi.org/10.2514/2.1056

Collections

Department of Aerospace Engineering, Article

Suggestions

OpenMETU
Core

Nonlinear flutter calculations using finite elements in a direct Eulerian-Lagrangian formulation Seber, Guclu; Bendiksen, Oddvar O. (American Institute of Aeronautics and Astronautics (AIAA), 2008-06-01) A fully nonlinear aeroelastic formulation of the direct Eulerian-Lagrangian computational scheme is presented in which both structural and aerodynamic nonlinearities are treated without approximations. The method is direct in the sense that the calculations are done at the finite element level, both in the fluid and structural domains, and the fluid-structure system is time-marched as a single dynamic system using a multistage Runge-Kutta scheme. The exact nonlinear boundary condition at the fluid-structure...
Computational study of flapping airfoil aerodynamics Tuncer, İsmail Hakkı (American Institute of Aeronautics and Astronautics (AIAA), 2000-05-01) Unsteady, viscous, low-speed flows over a NACA 0012 airfoil oscillated in plunge and/or pitch at various reduced frequency, amplitude, and phase shift are computed. Vortical wake formations, boundary-layer flows at the leading edge, the formation of leading-edge vortices and their downstream convection are presented in terms of unsteady particle traces. Flow separation characteristics and thrust-producing wake profiles are identified. Computed results compare well with water tunnel flow visualization and fo...
Computational study of subsonic flow over a delta canard-wing-body configuration Tuncer, İsmail Hakkı (American Institute of Aeronautics and Astronautics (AIAA), 1998-07-01) Subsonic flowfields over a close-coupled, delta canard-wing-body configuration at angles of attack of 20, 24,2, and 30 deg are computed using the OVERFLOW Navier-Stokes solver Computed flowfields are presented in terms of particle traces, surface streamlines, and leeward-side surface pressure distributions for the canard-on and -off configurations. The interaction between the canard and the wing vortices, wing vortex breakdown, and the influence of the canard on vortex breakdown are identified, The comparis...
Near-surface topology of unmanned combat air vehicle planform: Reynolds number dependence Elkhoury, M; Yavuz, Mehmet Metin; Rockwell, D (American Institute of Aeronautics and Astronautics (AIAA), 2005-09-01) The Reynolds number dependence of the near-surface flow structure and topology on a representative unmanned combat air vehicle planform is characterized using a technique of high-image-density particle image velocimetry, to complement classical dye visualization. Patterns of streamline topology, including bifurcation lines, as well as contours of streamwise and transverse velocity, surface-normal vorticity, and Reynolds stress correlation, all immediately adjacent to the surface of the planform, provide qua...
Sensitivity analysis using finite difference and analytical Jacobians Ezertaş, Ahmet Alper; Eyi, Sinan; Department of Aerospace Engineering (2009) The Flux Jacobian matrices, the elements of which are the derivatives of the flux vectors with respect to the flow variables, are needed to be evaluated in implicit flow solutions and in analytical sensitivity analyzing methods. The main motivation behind this thesis study is to explore the accuracy of the numerically evaluated flux Jacobian matrices and the effects of the errors in those matrices on the convergence of the flow solver, on the accuracy of the sensitivities and on the performance of the desig...

Citation Formats

Y. Özyörük, “Time-domain calculation of sound propagation in lined ducts with sheared flows,” AIAA JOURNAL, pp. 768–773, 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40644.