Accession Number : AD0616032

Title :   KINETIC EQUATION FOR A DILUTE GAS WITH SHORT-RANGE FORCES,

Corporate Author : NORTHWESTERN UNIV EVANSTON ILL TECHNOLOGICAL INST

Personal Author(s) : Harris,S. ; Lewis,M. B.

Report Date : 21 SEP 1964

Pagination or Media Count : 9

Abstract : The kinetic equation for a dilute gas with short-range forces is derived by a method which we believe to be physically more transparent than other methods. We first derive a density expansion for the correlation functions, the coefficients of which are functionals of F, the first distribution function. These functionals relax to timeindependent functionals over a time interval t (which we argue to be of the order of the duration of a collision) after a time t sub o (which is characterized by the phases) from the initial time. The functionals contain F over the interval + and therefore the resulting kinetic equation is nonMarkoffian. The non-Markoffian behavior is removed by further expanding the correlation functions in a parameter that is the ratio of the duration of a collision to the mean free time. The results for the correlation functions are carried to first order and agree with those of other methods for configurations where the particles are interacting, and therefore lead to the same kinetic equation, but are otherwise different. (Author)

Descriptors :   (*KINETIC THEORY, GASES), (*PARTIAL DIFFERENTIAL EQUATIONS, KINETIC THEORY), STATISTICAL FUNCTIONS, STATISTICAL MECHANICS, FORCE(MECHANICS), DENSITY, TIME, SERIES(MATHEMATICS), OPERATORS(MATHEMATICS)

Distribution Statement : APPROVED FOR PUBLIC RELEASE