Vectors toward Wall !!

souria · July 8, 2015, 05:15

Hey everyone,

I simulated flow and sediment transport on confluence (river confluence) and when I try to visualate the results, I find out that some vectors are directed toward the wall (see the images) ! It’s not possible I don't know why ?
Any idea, please ? !

PS. I join the images.

image1.png

image2.png

Thanks for your help

hwet · July 8, 2015, 20:37

It may be just a recirculation zone which can exist in low velocity regions. Have you got any real world data? It is possible that there is actually a recirculation zone in that region.

souria · July 13, 2015, 07:03

Thaks for your reply, no I don't get real world data ! bat the value of these vectors are very small compare to the rest of the domaine.

Souria

Quote:

Originally Posted by hwet

It may be just a recirculation zone which can exist in low velocity regions. Have you got any real world data? It is possible that there is actually a recirculation zone in that region.

hwet · July 13, 2015, 18:53

That is what i would have expected. Recirculation zones are low pressure/velocity zones.

ramakant · August 26, 2015, 03:59

Quote:

Originally Posted by hwet

That is what i would have expected. Recirculation zones are low pressure/velocity zones.

i wanto to know which software you have used for sediment transport modeling. i am trying to do that on STAR-CCM+

LuckyTran · August 29, 2015, 20:44

Is this a turbulent simulation? If no wall curvature correction is included in the turbulence model, it can result in vectors pointing into or out of walls. It can also be a result from inaccuracies in the pressure field, such as during the pressure correction step if you're using SIMPLE/PISO.

souria · September 1, 2015, 03:18

[QUOTE=LuckyTran;561607]Is this a turbulent simulation? If no wall curvature correction is included in the turbulence model, it can result in vectors pointing into or out of walls. It can also be a result from inaccuracies in the pressure field, such as during the pressure correction step if you're using SIMPLE/PISO.

For my case : it's turbulent flow, I used SIMPLE scheme ans no curvature coorections are added.

How can I fix it ? when you talk about pressure step correction, can I change it and how ?

Thanks for your answers.

Cheers

July 8, 2015, 05:15	Vectors toward Wall !!	#1
souria Member souria Join Date: Mar 2013 Location: Nancy Posts: 66 Rep Power: 13	Hey everyone, I simulated flow and sediment transport on confluence (river confluence) and when I try to visualate the results, I find out that some vectors are directed toward the wall (see the images) ! It’s not possible I don't know why ? Any idea, please ? ! PS. I join the images. image1.png image2.png Thanks for your help

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July 8, 2015, 20:37		#2
hwet Senior Member Join Date: Mar 2014 Posts: 375 Rep Power: 13	It may be just a recirculation zone which can exist in low velocity regions. Have you got any real world data? It is possible that there is actually a recirculation zone in that region.

July 13, 2015, 18:53		#4
hwet Senior Member Join Date: Mar 2014 Posts: 375 Rep Power: 13	That is what i would have expected. Recirculation zones are low pressure/velocity zones.

August 29, 2015, 20:44		#6
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	Is this a turbulent simulation? If no wall curvature correction is included in the turbulence model, it can result in vectors pointing into or out of walls. It can also be a result from inaccuracies in the pressure field, such as during the pressure correction step if you're using SIMPLE/PISO.

September 1, 2015, 03:18		#7
souria Member souria Join Date: Mar 2013 Location: Nancy Posts: 66 Rep Power: 13	[QUOTE=LuckyTran;561607]Is this a turbulent simulation? If no wall curvature correction is included in the turbulence model, it can result in vectors pointing into or out of walls. It can also be a result from inaccuracies in the pressure field, such as during the pressure correction step if you're using SIMPLE/PISO. For my case : it's turbulent flow, I used SIMPLE scheme ans no curvature coorections are added. How can I fix it ? when you talk about pressure step correction, can I change it and how ? Thanks for your answers. Cheers