Hi everyone,
I’m trying to create a simulation of a walk-in freezer cold storage for our undergraduate design paper project. It is modeled after a walk-in freezer design (space-wise) that is suitable for our “pretend” client and fits well within their store (we’re not actually doing this in real life, it’s more like a final year paper to gauge our understanding of everything we’ve learned in our 4 years of college).
My main goal is to see how the walk-in freezer cold storage would look like (especially temperature-wise) given the theoretical parameters we solved in the paper as input. So far, computations and everything are looking good (on paper). We just need a simulation to top things off and further support out paper
The problem arises in the simulation processing part (the mesh processing completed just fine). It says “Gauge pressure field started diverging to a value of -3.46838e+21 Pa near the position: [(-2.836, 5.516, 1.258)]. Please check the mesh quality near the reported location and try refining the mesh. If the problem occurred near a boundary, please check the boundary conditions. In case of doubt, please ask for assistance via our support chat.”.
This is the position in question (the one with the cross and yellow highlights):
I’m also not too familiar with the mesh things (which is what SimScale is suggesting as the problem), so I thought to ask for help first because I don’t wanna mess things up further.
Some supplementary details about my parameters that might help are below. I’m new to CFD in general, so there may be some mistakes in here and I’d appreciate any feedback and corrections. Perhaps some of my inputs are what’s causing the problems as well? I’m not sure. Anyway, here goes:
Velocity Inlet : Is set as a mass flow rate of 0.01855 kg/s across the 12 circles (evaporator fans) since I thought this is where the cold air from the evaporator exits and goes into the cold storage space. It’s actually 0.05565 kg/s per evaporator, and I divided it by three to get 0.01855 kg/s evenly for the three evaporator fan outlets (it’s the actual evaporator design we’re using)
Pressure Outlet: Is located there because that’s where the door to the cold storage walk-in freezer is, so it’s probably the “exit” or where pressure is relieved.
Product Load: Are basically the shelves containing the meat or the product we’re trying to store at freezing temperatures (I didn’t model the meat themselves to save time). I set it as a non-slip wall with flux heat source according to the product load we’ve computed (in Watts or W) and divided it by the amount of space/area (m^2) on the shelves available. Set it at an initial boundary temperature of 25°C since this is the receiving temperature of the meat.
Non-Wall + Floor (NPL): NPL just stands for Non-Product Load. This boundary includes non-walls (mostly evaporator faces) and the floor. Set it as a fixed value of 25°C because I thought I really did not need to know much about these in terms of heat transfer.
Polyurethane Walls: Are basically the walls + ceiling. Similar to the product load, we set it at an initial temperature of 25°C with a heat flux heat source of 5.75 W/m^2 according to the U value of Polyurethane at 100 mm thickness (around 0.23 W/m^2-C based on reliable sources). Basically, (0.23 W/m^2-C)*(25) = 5.75 W/m^2
Error Code (it stopped simulating at 5%):
This is the link to the project:
