Hello,
I started using MolFlowCLI and VacuumCOST. My study is similar to NEG saturation, I called it “Wall adsorption points saturation.” The principle is that at high vacuum, water molecules have a probability of being adsorbed when they collide with the wall, remaining for a certain period of time, which is called the “wall sojourn time”. A theory suggests that at high vacuum, there are discrete adsorption points on the wall, and water molecules will only stay for a long time if they collide with these adsorption points. When a certain number of water molecules have adsorbed onto an adsorption point, other water molecules will not remain upon collision with that point. This property is similar to the behavior of NEG pumps. Therefore, I want to use VacuumCOST to simulate this process.
Since VacuumCOST based on MolFlowCLI, and MolFlowCLI can only change the parameters shown in the diagram, it cannot set “wall sojourn time”.
I would like to kindly inquire whether it is possible to add the functionality ofchanging the “wall sojourn time” in MolFlowCLI.
Thank you very much for your time and consideration.
unfortunately you can’t use VacuumCOST to simulate water vapour: there’s one striking and fundamental difference between NEG-coating’s sticking coefficient, which is simply a sticking probability independent of the local pressure, and water vapour’s sticking probability which is described not just by a simple dimensionless value (the sticking coefficient) but rather depends on an equilibrium equation, like Clausius-Clapeyron or similar, where the local pressure is of paramount importance. The way Molflow+ is written now it can’t simulate this, we (Marton Ady) know how to modify the code but unfortunately there is no sufficient time and manpower to do it, since it would require a major re-writing of the core part of the code (physics). So, you can try to simulate it the way you’ve mentioned, but unless you can validate it against some measurements I wouldn’t trust the results.
Cheers, and good luck.
Thanks Roberto
My only request is that you kindly consider adding a feature in MolFlowCLI to allow for changing the ‘wall sojourn time,’ as is available in the MolFlow GUI.I believe this should not be a difficult task, as it would not require altering the core of MolFlow.
Thank you very much for your time and consideration.
Hello Marton,
Thank you sooooo much for adding the above feature so quickly; it has been a great help to me.
However, I encountered some issues when changing the parameters of the facets using molflowCLI. I cannot change the parameters of the named group. For example, I created a fd.zip file, selected some facets, and created a group ‘Cu’. When I try to change the parameters of the ‘Cu’ facets in PowerShell using the following command
and ’ ’ escaping besides " ", for example