Dear Marton,
When I use time-dependent simulation,e.g.,I set time span 1,50,50000,how can I get, after which time,the simulation can reach steady state？Is the data same as the constant flow?
Pictures below are different between constant flow data and time at 190000 sec data.The data about abs(force44-force46) is very different,does that mean the simulation still not steady at 190000 sec?
Best wishes
Sorry, it’s hard to reply without knowing the specifics of your geometry.
Yes, the constant flow option calculates the result based on the system state at the final moment. The final moment is the last defined moment plus half the time window.
Please note that t=50000s is likely not going to converge: Molflow needs to trace the molecules as physical time advances. With a typical molecule speed of 450m/s, and 0.1m free path between collisions, t=50000s requires 50000/(0.1/450)=225 million collisions for every single hit.
Molflow is typically good to simulate up to a few minutes at most.
Hello Marton,
here is my model
I’m glad you reply.I need to obtain force data every 40 seconds after the system stabilizes, so I’ve set a large time interval and total duration.
Now my question is how to determine when the system has reached a steady state, as only the force data recorded after the system stabilizes is useful.
Currently, my idea is to compare the system’s pressure with simulations where time-dependent isn’t set. Is this correct?
test paper.zip (799.6 KB)
You can see how the system state changes by manually stepping through moments or using the timewise plottter tool. When it doesn’t change anymore, it’s stable.
