What is “travel”’s exact definition?
According to help this is defined to be “number of iterations for a disturbance to cross the computational domain’s fluid region”.
Therefore it is something similar in nature to “time”, and in order to calculate this one must know the corresponding concept of “speed” and “distance” in the context.
But for flow simulation how could “speed” be known a priori? The flow might undergone different path depending on the geometry of the container (pipe, channel, etc.) and boundary and initial conditions, and its exact path can only be expected as a result from the simulation, but not a predictable value before running simulation. But in running the tutorial’s “conjugate heat transfer” example, I did find that:
- After a total of 128 iterations, Travel is determined to be 91
- Re-run, and upon start, Travel is determined to be 90 as early as the 4th iteration.
How is it determined before running? What is “disturbance” and “cross”? Why its values could be different at beginning and after finishing?