Vortex shedding - circular cylinder

allaffa · August 12, 2012, 12:16

Hi

I have to develop a numerical project as concerns the vortex shedding due to a circular cylider in a channel with water flowing. My professor compelled me to use the K-E model and told me not to use anu other model because it was the only one which was exposed during lessons.

I have set a problem 2D with Phoenics, the cylinder has a diameter of 0,06 m. It is in a channel whose dimensions are 3,00x1,00 m^2. in z axis i put 0,01m to be sure that the simulation was 2d. The cylinder is 1 metre far from the beginning.

The phenomenon reaches a stable situation at about 85000 seconds and i realize that it is quite strange.

I have to reproduce the result that I have found in litterature for Re=160, 200, 240, 270, 300. For this I have created a steady simulations and then a transient one restarting from the steady. In litterature it is said that the period goes from 70 to 150 seconds.

Anyway the period that i measure exporting the file forces-t.xls in MATLAB is 1500 seconds for the drag and 3000 for the lift.
It is really far from the litterature results.

Someone can help me?

Thanks!

cfdnewbie · August 25, 2012, 07:58

are the literature results for 3d or 2d runs?

allaffa · August 27, 2012, 11:26

litterature results are from 2d runs

August 12, 2012, 12:16	Vortex shedding - circular cylinder	#1
allaffa New Member Join Date: Aug 2012 Location: Milan Posts: 3 Rep Power: 13	Hi I have to develop a numerical project as concerns the vortex shedding due to a circular cylider in a channel with water flowing. My professor compelled me to use the K-E model and told me not to use anu other model because it was the only one which was exposed during lessons. I have set a problem 2D with Phoenics, the cylinder has a diameter of 0,06 m. It is in a channel whose dimensions are 3,00x1,00 m^2. in z axis i put 0,01m to be sure that the simulation was 2d. The cylinder is 1 metre far from the beginning. The phenomenon reaches a stable situation at about 85000 seconds and i realize that it is quite strange. I have to reproduce the result that I have found in litterature for Re=160, 200, 240, 270, 300. For this I have created a steady simulations and then a transient one restarting from the steady. In litterature it is said that the period goes from 70 to 150 seconds. Anyway the period that i measure exporting the file forces-t.xls in MATLAB is 1500 seconds for the drag and 3000 for the lift. It is really far from the litterature results. Someone can help me? Thanks! Last edited by allaffa; August 13, 2012 at 11:41.

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August 25, 2012, 07:58		#2
cfdnewbie Senior Member cfdnewbie Join Date: Mar 2010 Posts: 557 Rep Power: 20	are the literature results for 3d or 2d runs?

August 27, 2012, 11:26		#3
allaffa New Member Join Date: Aug 2012 Location: Milan Posts: 3 Rep Power: 13	litterature results are from 2d runs