I want to define a internal boundary in a block, where a constant value is fixed on this surface, is it possible in CFX 4.4 using user subroutine? Which type of patch should I define there?

Thanks

I copy the follow from the cfx document in page3-570. I hope it is helpful. Btw: Are you using the same ID in aoxue Forum ?

It is sometimes the case that you wish to prescribe the velocity at some internal point of the flow domain rather than giving a source of momentum. In this situation there are two ways of proceeding. First, it is possible to use an internal inlet and outlet, but they must be situated on a solid region. The second method, which should only be used with great care, uses source terms in the momentum equations by setting: SP = -c SU = c*value AM = 0 for all six facial components

Thanks, that is me.

Thanks for you information, but what I want to define there is not velocity. In short, it is a additional user scalar, and I need to set a boundary condition for such scalar inside the flow domain, and sovle a Poisson equation for such it, and this will have no direct influence to other variables.