Unsteady heat transfer of a monatomic gas between two coaxial circular cylinders
We consider a kinetic-theory treatment of the cylindrical unsteady heat transfer. A model kinetic equation of the BGK (Bhatnager-Gross-Krook) type is solved using the method of moments with a two-sided distribution function. We study the relations between the different macroscopic properties of the gas as the temperature, density, and heat flux with both the radial distance r and the time t. Also we study the problem from the viewpoint of irreversible thermodynamics and estimate the entropy, entropy production, entropy flux, thermodynamic forces, kinetic coefficients, the change in internal energy, and verify Onsager′s relation for nonequilibrium thermodynamic properties of the system.
Introduction to Dynamic Rarefied Gases. V. P. Shidlovskiy. Elsevier, New York. 168 pp. Tables. $12.50.
Introduction to Dynamic Rarefied Gases. V. P. Shidlovskiy. Elsevier, New York. 168 pp. Tables. $12.50. This book is the first in a period of more than ten years that is intended as an introductory text to rarefied gas dynamics. During that interval, a number of volumes dealing with the various aspects of the subject matter have been published, most notably the Proceedings of the International Symposia on Rarefied Gas Dynamics. None of these, however, by any stretch of the imagination could be construed as introductory works, and there is little doubt of the need for such a volume. The text under review fulfils this need quite adequately, notwithstanding its limited size. This reviewer, who is a novice in much of the subject matter, found the text to be clearly and concisely written. The author relies heavily on the open literature and frequently refers the reader to it, to obtain further details. He makes no pretext of undertaking an all-encompassing work, but rather is content to clarify the recent developments with a number of fundamental problems. The book's most notable omission is any comparison with experimental measurements although, as the author notes, it is also somewhat deficient in numerical methods of solution. With these limitations in mind, there is little doubt that Dr. Shidlovskiy has attained his desired goal of furnishing a text that will equip the interested reader with an up-to-date basic knowledge of the subject.
Shear-dependent viscosity in simple fluids
Abstract Computer simulation results are used to examine the shear-dependent viscosity of simple fluids. The prime purpose of the investigation was to examine the possible non-newtonian effects when the particles in a fluid interact through central forces. A range of spherical interactions was examined, including both potentials with a barrier and simple colloidal models, and in all cases the fluids were shear-thinning. The non-equilibrium radial distribution function for a soft potential is considerably more sensitive to shear rate than is that for the strongly repulsive model. Calculations of the hydrostatic pressure show that it increases with shear rate, demonstrating that the phenomena of shear thickening and shear dilatency — used interchangeably in the literature — are separate phenomena.