Learning Forum

[Nguyen Van Toan]

I am attempting to simulate a 1-D Stefan problem (with phase change) using Fluent. The issue at hand is condensation. The domain is meshed using a single cell layer in the y-direction. Other simulation parameters are illustrated in Figure (a). However, the obtained pressure distribution, depicted in Figure (b), does not match the theoretical calculation. The pressure distribution in the vapor region (black line) differs from the expected result (red line). Is there a possible solution to this discrepancy? Thank you very much!

[Rob]

Does the 1d calculation account for flow? Ie you're evaporating liquid to gas so you've got movement. 

[Nguyen Van Toan]

Thank you for your reply. The issue is that the vapor condenses and transforms into liquid, and the movement of the interface aligns with the theoretical calculation. However, the pressure distribution does not match our expectations. I doubt that Fluent can accurately simulate the 1D scenario.

[Rob]

More likely Fluent is modelling something that's not in the 1d code: it's a common issue as many theoretical models assume things to be constant/fixed but they're actually variables within the solvers.