Learning Forum

[2281935340]

Hi,

I use Fluent to simulate the nozzle. The outlet is set as a pressure outlet (see picture). The operating pressure is set to zero. The fluid is ideal air and not supersonic. The turbulence model is k-omega SST. The simulation is steady state. No backflow at the outlet. I found that the static pressure value of the nodes at the outlet does not match the pressure value I set (see picture). When I check the node values and the boundary condition value at the same time, the pressure distribution at the outlet is different again. I would like to ask what is the reason for this. I have read the guides but didn't find the answer.

Thanks in advance.

[Federico]

Fluent stores discrete values scalars at the cell centers, whereas face values are interpolated from the cell center values. Node values are explicitly defined or obtained by weighted averaging of the cell data. Various boundary conditions impose values of field variables at the domain boundaries, so mesh node values on these boundary zones are obtained by simple averaging of the adjacent boundary face data.