Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-18T18:18:52.452Z Has data issue: false hasContentIssue false

The decay of perturbations in an electrically conducting and thermally radiating gas

Published online by Cambridge University Press:  29 March 2006

M. Srinivasa Sarma
Affiliation:
Department of Mathematics, Indian Institute of Technology, Madras
L. V. K. V. Sarma
Affiliation:
Department of Mathematics, Indian Institute of Technology, Madras

Abstract

The decay of perturbations in an infinite, thermally radiating gas of perfect electrical conductivity in the presence of magnetic field is studied. Complete solutions for the decay of initial sinusoidal perturbations in the temperature, gas velocity and pressure are determined. The sinusoidal perturbations are superposed to yield solutions for the decay of initial ‘step’ temperature profiles consisting of a constant initial temperature perturbation inside a finite planar region, with zero temperature perturbation outside. For a broad range of small and intermediate Boltzmann numbers the cooling proceeds in time from being a constant-density cooling process to being a constant-pressure cooling process. The magnetic field causes slower temperature decay with time and makes the temperature perturbations tend to attain constant-pressure cooling values. It quickens the decay of velocity and pressure perturbations and thus the transition from a constant-density to a constant-pressure cooling process is hastened. This transition is produced by the magneto-acoustic waves generated near the profile edges by the radiative cooling.

Type
Research Article
Copyright
© 1973 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baldwin, B. S. 1962 N.A.S.A. Tech. Rep. R-138.
Cogley, A. C. & Vincenti, W. G. 1969 J. Fluid Mech. 49, 641.
Golitsyn, G. S. 1963 Bull. Acad. Sci. USSR Geophys. Ser. (English trans.) no. 589.
Helliwell, J. B. 1966 Phys. Fluids, 9, 1869.
Helliwell, J. B. & Nye, V. A. 1969 Quart. J. Mech. Appl. Math. 22, 453.
Kourganoff, V. 1952 Basic Methods in Transfer Problems. Oxford University Press.
Lick, W. 1964 J. Fluid Mech. 18, 274.
Moore, F. K. 1966 Phys. Fluids, 9, 70.
Nye, V. A. 1970a Quart. J. Mech. Appl. Math. 23, 265.
Nye, V. A. 1970b Quart. J. Mech. Appl. Math. 23, 247.
Olfe, D. B. & DePlomb, E. P. 1970 J. Fluid Mech. 40, 127.
Prokof'ev, V. A. 1957 Prikl. Math. Mech. 21, 775.
Riazantsev, I. S. 1959 Prikl. Math. Mech. 23, 1126.
Smith, P. W. 1957 J. Acoust. Soc. Am. 29, 693.
Solan, A. & Cohen, I. M. 1966 Phys. Fluids, 9, 2365.
Vincenti, W. G. & Baldwin, B. S. 1962 J. Fluid Mech. 12, 447.