[anengineer]

Hi!

I have a problem with my 2D axilsymmetric simulation and I was hoping you could help me. I am simulating a Stirling engine and I am having problems incorporating the porous model in the regenerator area.

The model without regenerator is validated but when I add the regenerator I get some results that don't make sense. Still, the engine is delivering the power it should and the pressure distribution is adequate.

The problem is the temperature distribution. On the one hand, the great thermal inertia of the regenerator area means that the temperature does not fluctuate sufficiently, as do the rest of the areas without a porous area.
On the other hand, at the outlet of the regenerator (in the cold zone), the temperature increases considerably, which causes the average temperature of that zone to be much higher than the rest. Before using the regenerator this does not happen and the temperature distribution is logical.

I incorporate images of the engine. The left area is the hot area (700 K) and the right area the cold area (343 K). In the center is the area with regenerator. I also attached the distribution contours of temperature, pressure and velocity. Finally, I attach the configuration of the porous zone.

Please, can someone explain to me why such a large temperature jump occurs at the regenerator outlet if the rest of the results are good?