Hi can you pl help me. I am working with microflow. I need to use slip flow condition on the wall. Fluid velocity on the wall is u=(delu/deln), where n is the normal coordinate pointing inward from the channel wall. Also we have to consider temperature as gas temperature-wall temperature=(delT/deln). Since it microchannel with rarefied flow We have to consider compressible ideal gas law. Total inlet pressure 272966 pa and outlet pressure is the atmospheric pressure is 100800pa. Tajul

To the best of my knowledge Fluent doesn't deal well with rarefied flows. The NS equations fall apart for non-continuum flows. Maybe you should try a solver employing the DSMC method (if there is any).

Thenk you for your response. Fluent can handle slip flow regime that is when Knudsen is number up to 0.1. Fluent can not be used in the transition regime or free molecule regime.