Collision Processes for High Temperature Gases

Abstract

In Chap. 3 it has been shown that the individual molecules in a gas are continuously at random motion, whose velocity distribution at a given instant defines the translational temperature of the particles. It is evident that the individual particles do not retain their original speed and direction of motion at all times, and only for rigid particles and in between collisions these may be considered constant with time. Although the particles may not be considered to be rigid sphere, such an assumption simplifies the mathematical procedure considerably, and any deviation from the rigid sphere model can be taken care of by using correction factors. While the temperature is considered to be linked with the energy distribution and hence requires the concept of equilibrium, one can assume local equilibrium to define the local temperature. Any deviation of the temperature from place to place is then considered as a deviation of the energy distribution, which causes transport of mass, momentum and energy from place to place. In this chapter, therefore, we consider the collision between the particles.