Fluid Film on parts of cylinder

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October 20, 2021, 03:36
Fluid Film on parts of cylinder
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Hi!

I am working on a simulation of the thermal effects of a fluid film on parts of a solid cylinder. For this problem, I used two different approaches, both showing a problem that I cannot solve.

1.) Geometry: Horizontal cylinder (solid), wrapped in a cube (gas). The cube has a shell region on the boundary to the cylinder in which the fluid film is supposed to flow. For the fluid film, I used a mass source term (field function) that is positive at the top of the cylinder and negative at the bottom, so there is a mass source at the top and a mass sink at the bottom. This works so far, but my problem is that I did not find any setting to set the temperature of the film "coming out" of the mass source. Does the mass source use the initial film temperature, or how am I able to set it?

EDIT: Solved -> Not possible, you have to determine a heat source corresponding to the mass source term to close the equations

2.) As an alternative, I let the box intersect with the cylinder and performed a subtract-action to generate edges of the box at the intersections with the cylinder (see picture attached). I would like to set the edges at the top (positive y-direction) as mass flow inlet for the film, the edges at the bottom as outlets. Unfortunately, StarCCM+ does not let me split the edges but does generate one boundary for all of the intersection edges. Does anyone of you have an idea, how to set separate boundary conditions for separate parts of the intersection edge?

EDIT: Solved -> When splitting the faces of the box, the boundary edges are split automatically as well. Works even better with CAD parts instead of simple geometry parts

Thank you so much in advance!
Attached Images
 Intersect Curve Example.png (88.3 KB, 12 views)

Last edited by tcr2231; November 8, 2021 at 09:27.

 October 22, 2021, 14:39 #2 New Member   Join Date: Oct 2021 Posts: 3 Rep Power: 2 [post deleted, see edit above] Last edited by tcr2231; November 8, 2021 at 09:29.