bundary condition
 

Dear All
Is imposing velocity with minus value at boundary condition correct?

Regards

it depends on the way you define the velocity! if it is set to normal to boundary then with minus the fluid would never enter the domain! but if you define it through the 3 coordinates it is correct as long as the inlet has the opposite orientation from the axes!

its a suction boundary condition and i know the velocity of exiting fluid.. so can i impose this velocity (which is minus) to bc?
another question is if fluent has any coordinate system? meaning that while imposing any b.c. one should have pay attention to the orientation of the flow?

i refuse to answer to your question, look first at the User Guide for such easy querries!