NTRS - NASA Technical Reports Server

Back to Results
Generation and Radiation of Acoustic Waves from a 2-D Shear LayerA parallel numerical simulation of the radiation of sound from an acoustic source inside a 2-D jet is presented in this paper. This basic benchmark problem is used as a test case for scattering problems that are presently being solved by using the Impedance Mismatch Method (IMM). In this technique, a solid body in the domain is represented by setting the acoustic impedance of each medium, encountered by a wave, to a different value. This impedance discrepancy results in reflected and scattered waves with appropriate amplitudes. The great advantage of the use of this method is that no modifications to a simple Cartesian grid need to be made for complicated geometry bodies. Thus, high order finite difference schemes may be applied simply to all parts of the domain. In the IMM, the total perturbation field is split into incident and scattered fields. The incident pressure is assumed to be known and the equivalent sources for the scattered field are associated with the presence of the scattering body (through the impedance mismatch) and the propagation of the incident field through a non-uniform flow. An earlier version of the technique could only handle uniform flow in the vicinity of the source and at the outflow boundary. Scattering problems in non-uniform mean flow are of great practical importance (for example, scattering from a high lift device in a non-uniform mean flow or the effects of a fuselage boundary layer). The solution to this benchmark problem, which has an acoustic wave propagating through a non-uniform mean flow, serves as a test case for the extensions of the IMM technique.
Document ID
Document Type
Conference Paper
Agarwal, Anurag
(Pennsylvania State Univ. University Park, PA United States)
Morris, Philip J.
(Pennsylvania State Univ. University Park, PA United States)
Date Acquired
August 20, 2013
Publication Date
August 1, 2000
Publication Information
Publication: Third Computational Aeroacoustics (CAA) Workshop on Benchmark Problems
Subject Category
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.

Related Records

IDRelationTitle20010061385Analytic PrimaryThird Computational Aeroacoustics (CAA) Workshop on Benchmark Problems
Document Inquiry
No Preview Available