Characteristics of Transient Behavior of Gas Flow in Microchannels

In this paper, a three-dimensional numerical model of transient incompressible gaseous flow in microchannels was established. The influence of changing the inlet velocity on the transient fluid flow is analyzed – using finite volume software (Fluent 6.3). The study showed that the transient period is decreased when the inlet velocity is increased, the maximum velocity is almost twice the entrance velocity, and the pressure has a small variation in the entrance of the channel and after that it becomes constant. It was concluded that despite of the fact that the transient behavior in micro systems is usually neglected due to its quick response, the transient terms of the Navier Stokes equations should be taken into consideration when dealing with flow behaviors that may occur in micro or nano seconds