Hi, I’m new to Molflow, going through the process of setting up my first simulation. However, there is a question of calculating the outgassing of the inlet face. For example, I have a cylindrical tube with an air source on one side and an air pump on the other. Now, I have the area of the air source surface(A=79.7123cm^2) , the pressure(p=1*10^-5Pa) at the air source surface, the legth of the tube(L=72cm)and the pumping speed(S=400L/s). If I want to simulate the process of molecular flow, how can I calculate the outgassing of the source surface? I’m looking forward to your reply. Thank you.
Hello and welcome.
In this case, simply set 400l/s pumping speed at the pump side (Molflow will calculate the equivalent sticking factor depending on the temperature and gas type - let me know if you need help setting these).
Then set an arbitrary outgassing rate on the source facet, and after running the simulation, check the pressure near it (measuring directly on an outgassing facet is distroting results). For measuring “nearby”, you have to insert a transparent sampling facet or use profiles or textures.
Since UHV simulations are linear, simply, after the first simulation results, scale your arbitrary outgassing rate so that the pressure matches 1E-5Pa on the source. Be careful with unit conversions (Molflow uses mbar.l/s).
Good luck, Marton
Hello dear Marton,
I am very glad to receive your reply. You’ve solved my problem, thank you very much.
Best regards!
Monica Liu