Steady case in user guide

[Justin Tso]

I noticed in the user guide for the demo project during the visualization of simulation results, you stated, "Since it is a steady case, only the last time step is needed." However, looking through the results of all the timesteps of that simulation, it would seem that the pressure and flow profiles are not constant with time. What is the rationale behind looking only at the last time step? I ask because I'm looking to compare two models under steady flow. While it would be convenient to compare only the last step for each model, it would seem like you're missing a lot of information with the earlier steps (as they are changing as well), and such a comparison might not be accurate.

[Weiguang Yang]

Usually, if the simulation is converged under steady flow conditions after n steps, the result for the last step is supposed to be "the same" as that for n+1. However, unsteadiness can exist even if the inflow condition is steady. For example, fluctuations in pressures and velocities can be created after a stenosis even if the inflow rate is constant. I would suggest comparing time-averaged results during a time interval.