How to Simulate Intake and compression stroke in CFD 2016?

[glenntws]

Hello,

I'm trying to simulate a Intake and Compression Stroke in CFD 2016.

I already tried many ways, compressible or incompressible flow, static or total temperature/pressure, but I always get wrong results 😞

The piston and valves are moved out of the cylinder and the modell, so I can define the volume of the intake port and the combustion chamber. After that, the parts get moved to their correct positions with the "starting position" of the Motion Tab. The parts all move correct.

All the solid parts are marked as Aluminum. The air volume I created with the geometry tool is described as variable air in a default scenario.

What data I have:

-Turbocharger is pumping air into cylinder (through the intake port) with:

Pressure: 2bar (absolute)

Temperature: 70° celsius

Which data I want to get:

-max. pressure at the end of the compression stroke

-max. temperature at the end of the compression stroke

The motion is controlled to simulate piston and valves at 12000rpm. The air is not faster than 180m/s (+10 maybe).

During the compression, the chamber is completely sealed. The piston has the exact same size as the cylinder.


So, what conditions do I have to use on the parts, which options I have to use when Solving and which solver is recommended?

I already tried so many variants, but not a single one worked...

Thanks for helping,

Glenn Töws

[glenntws]

To bad nowbody knows a answer 😞

[Jon.Wilde]

I think the issue here might be that CFD does not capture thermal expansion - which is likely playing a role here.

Saying that though - you would also need to set this up as a compressible model regardless. http://help.autodesk.com/view/SCDSE/2016/ENU/?guid=GUID-620F44CE-9506-4C48-9E9C-6C689345B008Total Pressure and Temp's and not static 🙂

Run for 0 iterations and see what conditions you have at the inlet to be sure CFD is correctly assigning them.