Learning Forum

[niels_normann]

Hallo. I am trying to simulate a heatexchanger in Ansys CFX where there exists 2 interphases. 1 with cold water-solid pipe and 2 solid pipe- fluegas (hot). I made 3 structered mesh in ICEM, 1 for the water domain, 1 for the solid and 1 for the fluegas. As seen in the picture below relatively many nodes are generated at the interphase for the flue structured mesh.

[DrAmine]

Show the mesh in CFX and check that again. Do not rely on boundary marks to qualify that!n

[niels_normann]

Thanks for the quick answer! nSo this is the mesh for the flue-gas - so CFX pre does import the nodes? There just something wrong with the boundary marks?nmesh for the wall(solid)nmesh for water domainnn

[DrAmine]

You created the mesh: does the mesh look as you expect? If you select one boundary and just hit Mesh Statistics in CFX: you will get more information regarding the mesh on that surface.n

[niels_normann]

Thanks that works i does import all the nodes, it just does not show by the interphase indicator. However, i thought that was the reason for the high temperature in the liquid water. it appears that the solver has a hard time for the volume fractions to converge, eventhough that the liquid water never meets the flue gas, so the composition should be constant. I tried the beta version where i just define the water domain and flue gas domain but that did not work (wrong temperatuer) i have also tried the homogenous model with free surface, where defined constant compostion for the flue and water. But that also does not seem right as there is no interphase as they never meet... So how to define liquid water and flue gas that never meets? n

[DrAmine]

Create a new thread with your new question and introduce the problem.n