Hi:

My model is a simple geometry like a pipe.

I used FLUENT to simulate the flow field.

But the velocity jumped near the outlet.

I tried the pressure outlet agian.

The velocity didn't jump near the outlet.

The flow was fully develop. But the velocity jumped in the outflow B.C.

Anyone could tell me why the outflow B.C. would have velocity jump??

The model like the pipe in this website

http://instruct1.cit.cornell.edu/cou...ipe1/step3.htm

Thanks a lot!!

Tim

Maybe the pipe is not long enough, for the flow to become fully developed. you may need a longer pipe. Or give a velocity profile in outlet boundary, using Define-> Profile...