The Effect of Thermal Barriers on Sound Wave Propagation

Abstract

Sound propagation through regions of non-uniform temperature distribution in a gas is studied numerically. The main objective of this study is to determine the impact of temperature gradients on the sound wave parameters and to evaluate the effectiveness of using regions of hot gas as sound barrier. Such regions of hot gas (low acoustic impedance) can be generated by remotely depositing energy into a selected volume of gas, for example, by means of electrical discharge. Sound attenuation through the hot gas region is studied systematically for a range of sound wave and thermal field parameters by solving the two-dimensional unsteady compressible Euler's equations along with the ideal gas state equation using a finite volume scheme. Particular attention is given to the practical case when sound wavelength is comparable to the thickness of the thermal barrier. The present two-dimensional model indicates that considerable sound attenuation can be achieved at large incidence angles and a critical angle for total internal reflection is possible.

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References

Ganguly

B.N.

Bletzinger

and Garscadden

, “Shock wave damping and dispersion in non-equilibrium low pressure argon plasmas,” Physics Letters A, 1997, Vol. 230, p. 218–222.

Soukhomlinov

V.S.

Kolosov

V.Y.

Sheverev

V.A.

and Ötügen

M.V.

“Acoustic dispersion in glow discharge plasma: Aphenomenological analysis,”

Phys. Fluids., 2001, Vol. 14, No. 1, pp. 427–429.

Soukhomlinov

V.S.

Kolosov

Sheverev

V.A.

and Ötügen

M.V.

, “Formation and propagation of a shock wave in a gas with temperature gradients,” J. Fluid Mech., 2002, 473, pp. 245–264.

Roth

J.R.

Sherman

D.M.

and Wilkinson

S.P.

, “Electrohydrodynamic flow control with a glow-discharge surface plasma,” AIAA Journal, 2000, Vol. 38, No. 7, pp. 1166–1172.

Girgis

I.G.

Shneider

M.N.

Macheret

S.O.

Brown

G.L.

and Miles

R.B.

, “Creation of steering moments in a supersonic flow by off-axis plasma heat addition,” AIAA paper no. 02–0129, January 2002.

Corke

T.C.

Jumper

E.J.

Port

M.L.

, and Orlov

, “Application of weakly-ionized plasmas as wing flow-control devices,” AIAA paper no 2002–0350, January 2002.

Stepaniuk

V. P.

Tarau

Ötügen

M.V.

Sheverev

V.A.

Soukhomlinov

V.S.

, and Raman

, “Acoustic Wave Attenuation Through Glow Discharge Plasma,” AIAA paper no 2002–2433, June 2002.

Stepaniuk

V.P.

Sheverev

V.A.

Ötügen

M.V.

Tarau

Raman

Soukhomlinov

, “Sound Attenuation by Glow Discharge Plasma,” AIAA paper no 2003–0371, January 2003.

Enflo

B.O.

and Enflo

P.H.

, “Sound wave propagation from a point source over homogeneous surface and over a surface with an impedance discontinuity,” J. Acoust. Soc. Am., 1987, Vol. 82, pp. 2123–2135.

10.

Rasmussen

K.B.

, “A note on the calculation of sound propagation over impedance jumps and screens,” J. Sound Vib., 1982, Vol. 84, pp. 598–602.

11.

Zhu

Stinson

M.R.

, and Daigle

G.A.

, “Scattering from impedance gratings and surface wave formation,” J. Acoust. Soc. Am., 2002, Vol 111, No. 5, pp. 1996–2012.

12.

Chien

C.F.

, and Soroka

W.W.

, “Sound propagation along an impedance plane,” J. Sound Vib., 1975, Vol. 43, No. 1, pp. 9–20.

13.

Gilbert

K.E.

and White

M.J.

, “Application of the parabolic equation to sound propagation in a refracting atmosphere,” J. Acoust. Soc. Am., 1989, Vol. 85, pp. 630–637.

14.

Chandler-Wilde

S.N.

and Hothersall

D.C.

, “Sound propagation above an inhomogeneous impedance plane,” J. Sound Vib., 1985, Vol. 98, pp. 475–491.

15.

Tarau

and Ötügen

M.V.

, “Propagation of acoustic waves through regions of non-uniform temperature,” International Journal of Aeroacoustics, 2002, Vol.1, No. 2, pp.165–181.

16.

Kinsler

E.L.

Frey

A.R.

Coppens

A.B.

Sanders

J.V.

, “Fundamentals of acoustics,” John Wiley & Sons, Third Edition, 1980.

17.

Skudrzyk

, “The foundations of acoustics,” Springer-Verlag Wien New York, 1971.

18.

Seto

W.W.

, “Acoustics: Theory and problems,” Shaum's Outline Series, McGraw Hill, New York, 1971.