NONLINEAR COUETTE-FLOW IN A DILUTE GAS - COMPARISON BETWEEN THEORY AND MOLECULAR-DYNAMICS SIMULATION

Nonlinear transport properties of a d-dimensional dilute gas subjected to a planar Couette flow are determined. The results are obtained fro m a kinetic model that accounts for the correct value of the Prandtl n umber. The solution is characterized by constant pressure and linear v elocity and parabolic temperature profiles with respect to a scaled va riable. The main transport coefficients are explicitly obtained as non linear functions of the reduced shear rate. A comparison with recent m olecular-dynamics simulations of a bidimensional gas of hard disks [D. Risso and P. Cordero, Phys. Rev. E 56, 489 (1997)] is carried out. Su ch a comparison shows that our results are in better agreement with th e computer simulations than those previously derived from other approx imations, especially in the case of the thermal conductivity tensor.