khalighi_mani_ham_moin_2010

Summary

Prediction of sound generated by complex flows at low Mach numbers. Y. Khalighi, A. Mani, F. Ham and P. Moin. AIAA Journal, 48(2):306-316, 2010. (URL)

Abstract

We present a computational aeroacoustics method to evaluate sound generated by low Mach number flows in complex confgurations in which turbulence interacts with arbitrarily shaped solid objects. This hybrid approach is based on Lighthill's acoustic analogy in conjunction with sound source information from an incompressible calculation. In this method, Lighthill's equation is solved using a boundary element method that allows the effect of scattered sound from arbitrarily shaped solid objects to be incorporated. We present validation studies for sound generated by laminar and turbulent flows over a circular cylinder at Re = 100 and 10,000, respectively. Our hybrid approach is validated against directly computed sound using a high-order compressible flow solver as well as the solution of the Ffowcs Williams and Hawkings equation in conjunction with compressible sound sources. We demonstrate that the sound predicted by a second-order hybrid approach is as accurate as sound directly computed by a sixth-order compressible ?ow solver in the frequency range in which low-order numerics can accurately resolve the flow structures. As an example of an engineering problem, we calculated the sound generated by flow over an automobile side-view mirror and compared it to experimental measurements.

Bibtex entry

@ARTICLE { khalighi_mani_ham_moin_2010, ABSTRACT = { We present a computational aeroacoustics method to evaluate sound generated by low Mach number flows in complex confgurations in which turbulence interacts with arbitrarily shaped solid objects. This hybrid approach is based on Lighthill's acoustic analogy in conjunction with sound source information from an incompressible calculation. In this method, Lighthill's equation is solved using a boundary element method that allows the effect of scattered sound from arbitrarily shaped solid objects to be incorporated. We present validation studies for sound generated by laminar and turbulent flows over a circular cylinder at Re = 100 and 10,000, respectively. Our hybrid approach is validated against directly computed sound using a high-order compressible flow solver as well as the solution of the Ffowcs Williams and Hawkings equation in conjunction with compressible sound sources. We demonstrate that the sound predicted by a second-order hybrid approach is as accurate as sound directly computed by a sixth-order compressible ?ow solver in the frequency range in which low-order numerics can accurately resolve the flow structures. As an example of an engineering problem, we calculated the sound generated by flow over an automobile side-view mirror and compared it to experimental measurements. }, AUTHOR = { Y. Khalighi and A. Mani and F. Ham and P. Moin }, JOURNAL = { AIAA Journal }, NUMBER = { 2 }, PAGES = { 306--316 }, TITLE = { Prediction of sound generated by complex flows at low {M}ach numbers }, URL = { http://dx.doi.org/10.2514/1.42583 }, VOLUME = { 48 }, YEAR = { 2010 }, 1 = { http://dx.doi.org/10.2514/1.42583 }, }