modeling freestream in an big Volume with gravity

Raambi · May 9, 2011, 06:02

Hello everybody!

I get big problems with my solution, if im trying to solve with gravity.

I am modeling a freestream in a big volume/room. The flow enter the room with 4 m/s. The floor and the blanket are defined as wall-boundaries and the walls of the room as pressureoutlets.

I work with ccm+ and my models are:

gravity
Ideal Gas
K-Omega SST Turbulence
Multicomponent (Mix of two non-reacting Gases)
RANS
Segregated Flow (Isothermal)
Steady
3D

without gravity the freestream looks very normal/good i think. But if i switch the gravity on i get without any reason very high velocities in my volume. These velocities are much higher than the freestream and it ruined my solution. If i solve until the residuals are convergated, the freestream goes very fast up to the blanket and the straight to the right. This doesnt seem very natural.....

Big Sorry for my English i hope u can understand my problem anyhow!

regards

Raambi · May 10, 2011, 07:04

Could nobody help me? Is my english too worse or do u have not enough informations?

Pls! I need help!

May 9, 2011, 06:02	modeling freestream in an big Volume with gravity	#1
Raambi New Member Join Date: May 2011 Posts: 6 Rep Power: 14	Hello everybody! I get big problems with my solution, if im trying to solve with gravity. I am modeling a freestream in a big volume/room. The flow enter the room with 4 m/s. The floor and the blanket are defined as wall-boundaries and the walls of the room as pressureoutlets. I work with ccm+ and my models are: gravity Ideal Gas K-Omega SST Turbulence Multicomponent (Mix of two non-reacting Gases) RANS Segregated Flow (Isothermal) Steady 3D without gravity the freestream looks very normal/good i think. But if i switch the gravity on i get without any reason very high velocities in my volume. These velocities are much higher than the freestream and it ruined my solution. If i solve until the residuals are convergated, the freestream goes very fast up to the blanket and the straight to the right. This doesnt seem very natural..... Big Sorry for my English i hope u can understand my problem anyhow! regards Last edited by Raambi; May 10, 2011 at 07:02.

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May 10, 2011, 07:04		#2
Raambi New Member Join Date: May 2011 Posts: 6 Rep Power: 14	Could nobody help me? Is my english too worse or do u have not enough informations? Pls! I need help!