We consider a body immersed in a perfect gas and moving under the action of a constant force. Body and gas are in thermal equilibrium. We assume a stochastic interaction body/medium: when a particle of the medium hits the body, it is absorbed and immediately re-emitted with a Maxwellian distribution. This system gives rise to a microscopic model of friction. We study the approach of the body velocity to the limiting velocity and prove that, under suitable smallness assumptions, the approach to equilibrium is where is the dimension of the space, and is a positive constant. This approach is not exponential, as typical in friction problems, and even slower than for the same problem with elastic collisions.
@article{M2AN_2008__42_2_263_0, author = {Aoki, Kazuo and Cavallaro, Guido and Marchioro, Carlo and Pulvirenti, Mario}, title = {On the motion of a body in thermal equilibrium immersed in a perfect gas}, journal = {ESAIM: Mathematical Modelling and Numerical Analysis - Mod\'elisation Math\'ematique et Analyse Num\'erique}, volume = {42}, year = {2008}, pages = {263-275}, doi = {10.1051/m2an:2008007}, mrnumber = {2405148}, zbl = {1133.76046}, language = {en}, url = {http://dml.mathdoc.fr/item/M2AN_2008__42_2_263_0} }
Aoki, Kazuo; Cavallaro, Guido; Marchioro, Carlo; Pulvirenti, Mario. On the motion of a body in thermal equilibrium immersed in a perfect gas. ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique, Tome 42 (2008) pp. 263-275. doi : 10.1051/m2an:2008007. http://gdmltest.u-ga.fr/item/M2AN_2008__42_2_263_0/
[1] The Vlasov dynamics and its fluctuations in the limit of interacting classical particles. Comm. Math. Phys. 56 (1977) 101-113. | MR 475547 | Zbl 1155.81383
and ,[2] On the long time behavior of infinitely extended systems of particles interacting via Kac Potentials. J. Stat. Phys. 108 (2002) 317-339. | MR 1909561 | Zbl 1031.82050
, and ,[3] Approach to equilibrium in a microscopic model of friction. Comm. Math. Phys. 264 (2006) 167-189. | MR 2212220 | Zbl 1113.82059
, and ,[4] On a microscopic model of viscous friction. Math. Models Methods Appl. Sci. 17 (2007) 1369-1403. | MR 2353147 | Zbl pre05274854
, and ,[5] On the motion of a convex body interacting with a perfect gas in the mean-field approximation. Rend. Mat. Appl. 27 (2007) 123-145. | MR 2361025 | Zbl 1134.76055
,[6] Vlasov equations. Sov. J. Funct. Anal. 13 (1979) 115-123. | MR 541637 | Zbl 0422.35068
,[7] Stationary motion of the adiabatic piston. Physica A 268 (1999) 412-423.
and ,[8] Scaling dynamics of a massive piston in a ideal gas, in Hard Ball Systems and the Lorentz Gas, Encycl. Math. Sci. 101, Springer, Berlin (2000) 217-227. | MR 1805331 | Zbl 1127.82308
, and ,[9] An Introduction to the Nonlinear Boltzmann-Vlasov Equation, in Kinetic Theories and the Boltzmann Equation, Montecatini (1981), Lecture Notes in Math. 1048, Springer, Berlin (1984) 60-110. | MR 740721 | Zbl 0575.76120
,[10] On the Vlasov hierarchy. Math. Meth. Appl. Sci. 3 (1981) 445-455. | MR 657065 | Zbl 0492.35067
,