Hi,everyone.

A kind of gas(air)is flowing through a tube. Another kind of gas(CH4) is added into the tube through all the side walls of the tube.

I define the inlet of tube as one mass-flow-inlet(air,0.08kg/s).And I define all the side walls as one mass-flow-inlet(CH4,0.027kg/s).And I definethe outlet of the tube as pressure-outlet.

But when the solution is convergenced, I find that the mass faction of CH4 species is very small(about 3*e-22).

How can I solve the problem? Any answner is welcome.

Thank you.

lizihujx 2000.1.17

Check your velocity vector direction! We've had a similar case here where we had used direction vector as opposed to 'normal to boundary'. like your case, the model ran, reported the correct mass flows, but was wrong.

Hope this helps,

Angus