How to specify pressure outlet and inlet so that a backflow won't occur?If flow is from a big diameter inlet to a small diameter outlet.

Try extending your outlet section (grid) further downstream.

Chinor

thanks i will try it....

Hi all In modelling turbulent flow over an airfoil i am having problems predicting separation. An obviuos choice is to determine when the skin friction coefficient becomes negative. However fluent doesnt seem to plot neagtive coefficents for despite the fact that the flow is clearly separated(The velocity vectors show flow reversal). have i got my settings wrong or am i using the plot facility wrong. regards nick