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First, select pipewall in the Boundary Conditions menu, as shown below.
As can be seen in the image above the Type should have been automatically set to wall. If the Type is not set to wall, then set it to wall. Now, no further changes are needed for the pipe_wall boundary condition. Also make sure that the boundary condition Type for interior-solid is Interior.
It is a good practice to change the Reference Values now, these values can be useful when we are postprocessing results later on. (Click)Problem Setup > Reference Values. Select Compute from as inlet.
Save
In order to save your work (Click)File > Save Project as shown in the image below.