Transient CFD simulation for engine intake
I know there's few threads about this already, but still no actual answers were given. So once again, how should i set the boundary conditions for transient flow simulation in solidworks flow?
Now i have set time dependant pressure drop tables for the outlet ports as adviced in some tutorials. As we know, then it's like the valves never get closed and the air never stops flowing through because inertia of air mass. Also that causes lack of the positive pressure pulses traveling back and forth to the plenum what's pretty much what i would like to see.
So obviously i should be using mass flow instead of pressure for my outlet boundary conditions, but is there any suggestions how should i estimate that flow speed and plot shape?
Even with that spot on the simulation is not really realistic because the pressure pulses in system wouldn't then effect the flow to cylinders. Am i right assuming that's just not possible to get this right in solidworks flow simulation?
There's link to the GIF file showing my result with said pressure drop method:
And the model:
Opel C25XE Intake
Found interesting pdf about camshaft profile and mass flow at intake valves: http://www.fisita.com/education/congress/sc10/fisita2010scp24.pdf
So i plotted their diagram in excel, and matched (educated guess) the numbers to engine im trying to simulate. Hell of a job in excel just to find out that flow only support positive mass flow numbers :D Anyone know if that can be changed somehow?