Learning Forum

[SEANGHAI]

Hello! I have a problem with the results of Relative Humidity that exceed 100%, the maximum results of relative humidity in my problem is 650%. I saw many people in this group facing this problem as well, but when I followed their solution, I still cannot fix this problem, this is why I come here again. In my problem, I have 2 inlets of air flow rate, one outlet of air flow rate, another one is Pressure outlet, Also there are 3 types of cell zone for apply species like Tritium and Water Vapor, another cell zone for applying air source and the last one cell zone for applying sink of air. I used Realizable K-epsilon model and the results of Relative humidity is so weird, it increased until 650%. Why? Thank you! I will always appreciate all your comments and advice.n

[DrAmine]

Why is RH above 100% When does it happen in reality? Yeah fogging, raining, etc..nnIn the numerical modeling the real arguments remain + some argument due to bad convergence, numerical approximations, user errors, discretization errors, etc...nSo to deal with real arguments and if it is expected that the mixture becomes supersaturated then a condensation model is required.n

[SEANGHAI]

Thank you !Sir! for your reply. For my problem, there is no error while running the calculation at all, and at 140 iterations, solution is converged. My flow calculation is in the building, and I do not expect that the RH increased until 650%. According to your explanation, should I reduce the amount of the Water Vapor on the cell zone in the domain (building)? I do not know what to do exactly to deal with this problem, can you detail me more? Anyway, I will try to reduce the amount of water vapor first, and I will come back to inform you about the results. Thank you for your understanding and kindness!n

[SEANGHAI]

I already tried to reduce the amount of the Water Vapor which applied to the cell zone in the domain, and the results of RH is under 100% which is what the results that I expected. However, I am curious that whether there is another way to fix this problem? In my problem, I do not want to reduce the amount to Water Vapor! Thank you!n

[DrAmine]

There is no problem here if everything else is set and quantified properly: you are not accounting for condensation and for that reason you will need to live with it or to account / model it.n