# Accession Number:

## AD0722184

# Title:

## Truncation Procedure for the Spatially Homogeneous Boltzmann Equation,

# Descriptive Note:

# Corporate Author:

## NORTHWESTERN UNIV EVANSTON ILL TECHNOLOGICAL INST

# Personal Author(s):

# Report Date:

## 1970-10-26

# Pagination or Media Count:

## 11.0

# Abstract:

The usual truncation procedure for coefficient equations is shown to be inconsistent for a certain class of initial-value problems in that it retains terms of one magnitude while neglecting terms of the same or greater magnitude. Moreover, it predicts moments which are strongly dependent on the zero-order function used in the expansion of the distribution function. A truncation procedure is developed for spatially homogeneous time relaxation problems which gives rise to moments which are independent of the particular zero-order function used in the expansion and which, for certain general initial distribution functions, are correct in value and first-derivative both initially and in equilibrium. As an example, this procedure is used to solve the two-temperature single-gas mixture problem. Author

# Descriptors:

# Subject Categories:

- Physical Chemistry
- Thermodynamics