Time trace between planes

[jasonwarrenbritton]

Is there a tool within Simulation CFD to extract the time it takes a particle to cross a plane through the geometry and then reach another plane through the geometry toward the exit.  To describe this question further, This does not mean the Inlet and the outlet, this is some plane down the line after the inlet and/or multiple inlets to a plane that is not quite to the exit.

[heath.houghton · Accepted solution]

There isn't such a tool exactly, but you can make use of the tools in the trace particles to get what you want. It will just take a little more work. Seed the particle on the first plane. Then in the trace particle dialog, select trace list and then mass. Massed particles start at the seed, as opposed to massless which go through the seed. Enable mass and you should see the difference. Change the density to that of air and radius to something very small like 1e-6. Then change the timestep to a small number like 1e-4 or 1e-5. At this point your particle either falls short of the second plane or goes through it. Since we have a unit timestep (easier for multiplying later), we can then hit apply to exit the mass particle dialog and fine tune how many seconds we are displaying of the particle travel. Right click on "Set" on the traces dialog and select "set properties". Adjust the max steps number until your trace particle exactly reaches the second plane. Multiply max steps by the timestep size you used in the massed particle dialog, and that is your seconds it took to go from plane 1 to plane 2.

Hope this helps.

Heath

[jasonwarrenbritton]

Heath

I will try that first thing in the morning Tomorrow. Thank You for your
quick response.

Will Post my results to follow.

[jasonwarrenbritton]

That Worked wonderful.  Attached is an image which showes points on a horizontal plane roughly one quarter height of vessel and going to a plane which is vertical roughly half way through system.

I chose to use 16 trace pts on the plane.  Doing this makes machine run very slow, but does get the answer.  I simply adjusted the set property timestep count until I saw a trace pass my plane which gives me the fastest path of residence time for a pt to travel that distance.

 Thanks for your time.