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Space-eigenvalue problems in the kinetic theory of gases

Published online by Cambridge University Press:  29 March 2006

M. M. R. Williams
Affiliation:
Nuclear Engineering Department, Queen Mary College, University of London
J. Spain
Affiliation:
Nuclear Engineering Department, Queen Mary College, University of London

Abstract

The existence of elementary, exponential solutions of the linear Boltzmann equation for gases is examined. Using the hard-sphere model of scattering, it is found that, in problems involving velocity perturbations, there are no discrete non-zero eigenvalues. Thus the relaxation to the asymptotic distribution is non-exponential and is described by the continuum eigenfunctions. For temperature perturbations, however, we find two non-zero discrete eigenvalues whose values are ±0·975 in units of the minimum scattering cross-section. Relaxation to the asymptotic distribution is therefore exponential, although still very rapid.

The conclusions stated above are based upon a truncation of the scattering kernel and a subsequent numerical solution of the resulting integral equations.

Type
Research Article
Copyright
© 1970 Cambridge University Press

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References

Buckner, J. K. & Ferziger, J. H. 1966 Phys. Fluids, 9, 2315.
Cercignani, C. 1962 Ann. Phys. 20, 21.
Chapman, S. 1917 Phil. Trans. A 217, 115.
Enskog, D. 1911 Phys. Z. 12, 53.
Grad, H. 1963 Phys. Fluids, 6, 147.
Grad, H. 1964 Proc. Int. Seminar on Transport Properties in Gases. Brown University.
Grad, H. 1966 J. SIAM, Appl. Math. 14, 93.
Koppel, J. 1963 Nucl. Sci. & Engng, 16, 101.
Kramers, H. A. 1949 Nuovo Cimento suppl. 6, 887.
Kuscer, I. & Williams, M. M. R. 1967 Phys. Fluids, 10, 1922.
Loyalka, S. K. & Ferziger, J. H. 1967 Phys. Fluids, 10, 1833.
Loyalka, S. K. & Ferziger, J. H. 1968 Phys. Fluids, 11, 1668.
Mott-Smith, H. M. 1954 Lincoln Laboratory, M.I.T., Rep. V-2.
Rahman, M. & Sundaresan, M. K. 1968 Can. J. Phys. 21, 246.
Riesz, F. & Sz-Nagy, B. 1955 Functional Analysis. New York: Ungar.
Sirovich, L. & Thurber, J. K. 1963 3rd Int. Symp. Rarefied Gas Dynamics, 1, 159.
Wang-Chang, C. S. & Uhlenbeck, G. E. 1952 Engng Res. Inst., University of Michigan, Rep. N 6 onr-23222, Project M 999.
Wang-Chang, C. S. & Uhlenbeck, G. E. 1953 Engng Res. Inst., University of Michigan, Rep. N 6 onr-23222, Project M 999.
Wang-Chang, C. S. & Uhlenbeck, G. E. 1954 Engng Res. Inst., University of Michigan, Rep. N 6 onr-23222.
Wang-Chang, C. S. & Uhlenbeck, G. E. 1956 Engng Res. Inst., University of Michigan, Rep. Non-r-122 415.
Welander, P. 1954 Ark. Fys. 7, 50.
Williams, M. M. R. 1966a The Slowing Down and Thermalization of Neutrons. Amsterdam: North-Holland.
Williams, M. M. R. 1966b Nucl. Sci. & Engng, 26, 262.
Williams, M. M. R. 1968 Nucl. Sci. & Engng, 33, 262.
Williams, M. M. R. 1969 J. Fluid Mech. 36, 145.
Wood, J. 1966 J. Nucl. Energy, 20, 219.