The time step is dynamic and will change so the actual solve time maybe a lot less than 30 hours and is an estimate at best. More help could be provided with some description of the problem to be solved. For instance, if the object is the diffusion of some quantity, like heat, then the use of flow freezing can speed up the calc substantially but it depends on what you are doing and whether the technique is appropriate. Just mucking with the time step directly can lead to the computation of non realistic results if the situation is not well understood.
Are you sure you didn't set the 0.1 seconds under Calculation control -> Saving by accident?
That field controls how many plot steps get saved but doesn't affect the calculation time step
If you set it under Calculation Control -> Solving you will need to change Time Step -> Auto to Manual and then input a calculation time step size there
Below are some tips that I use.
1. Set up solving as shown. If the solve goes over the physical time you may increase the % required for solving.
If you only tick Physical time the solve will be fast.
2. Enter manual (suggested time step) - but as discussed by others Flow will calculate this.
In this example the 300 s 'step' is what will be exported to excel.
3. Full Results 'step' is what you can select under Results time step (to show section plots etc) (right click results and select the time step). In this example every 3600 s is saved. If the save value is small the solve will take ages - so make the Period as large as reasonable.
My preference is not to use freezing... but you can test this.
Solve with course mesh settings until you get the bugs out. Then increase mesh slowly until you only get a small change between the previous solve and the finer mesh.
If you can do share your model.
*Let us know what your solution is...*
Guys, first of all let me thank you for trying to help me promptly. My project is to study the flow in a T shaped junction, in wich two fluids enter in opposite ends, they mix, and exit on the other end ( I'll post a snap later). The flow occurs at a very low Re so it is strongly laminar. As we have almost no advection, the mixing is strongly diffusive, so it means that it is hard to get a efficient mix in a short time. The solution we're testing is to have pulsed flows with opposite phase on both ends. That's what I'm trying to simulate. First of all let me tell you that for some reason I don't have flow freezing option in solve options. I've also read about the possibility to use "nested iterations". Is this for me?
Thank you again for your help with this issue