Discussion Forum

Hello everyone!

I am quite new to COMSOL and I am currently working on the 3D geometry I hereby attach. The geometry is built in COMSOL Multiphysics 5.0.

The model is referring to a 23 meters high vertical buffer system, used for the storage and refrigeration of carts containing food (working 24/7 for 365 days per year, at the same regime).

Carts are assigned to domains 2-19 (I have simply modeled them as parallelepipeds, and assigned Steel material properties to them): their initial temperature is set at 10°C.

Each Vertical Buffer is equipped with 2 AHU for ambient cooling at 0/+2 °C: I have modeled all plenums needed for the air distribution at the various levels of the structure, and correctly set Inflow and Outflow velocities (computed considering the air mass flow from AHU).

The model has to consider also the fact that, when carts are introduced inside the structure, warm air from external ambient (22°C) is introduced into the vertical buffer: I have decided to approximate this condition and I have computed Inflow and Outflow velocities and set them on two little surfaces of the structure.

I would like to perform a stationary COMSOL simulation in order to evaluate the temperature/velocity of the air inside the volume and the surface temperature on each cart.

I have adopted the Turbulent Flow module combined to the Heat Transfer in Solid one (assigning anyway the 'Heat transfer in fluid' property to domain 1), but the model does not converge. I cannot understand if this is due to a not good mesh or if I have made some conceptual errors in the model definition.

I have tried to mesh the model through both a Physics-controlled mesh command (Normal and fine fluid-dynamic mesh) and a User-controlled one (3D free-tetrahedal mesh).

Thank you for your help and suggestions!

Alessandro