Are backward scheme and the upwind scheme the same thing in FDM?

lnk · August 29, 2012, 11:03

Hi everyone,

Are backward scheme and the upwind scheme the same thing in FDM?

Best,
lnk

michujo · August 30, 2012, 03:38

Hi, not exactly. The upwind scheme uses the nodes located upstream (hence the name "upwind") to calculate the gradients. This is, depending on the value of the velocity, the upwind scheme might be a backward scheme (positive velocity, flow goes from left to right) or forward scheme (negative velocity, flow goes from right to left).

The same goes for the south and north nodes.

Have a look at the book "Numerical heat transfer and fluid flow" by S. Patankar, it is all in there.

Cheers,
Michujo.

August 29, 2012, 11:03	Are backward scheme and the upwind scheme the same thing in FDM?	#1
lnk Senior Member lnk Join Date: Feb 2011 Location: Switzerland Posts: 118 Rep Power: 15	Hi everyone, Are backward scheme and the upwind scheme the same thing in FDM? Best, lnk

August 30, 2012, 03:38		#2
michujo Senior Member Join Date: Dec 2011 Location: Madrid, Spain Posts: 134 Rep Power: 15	Hi, not exactly. The upwind scheme uses the nodes located upstream (hence the name "upwind") to calculate the gradients. This is, depending on the value of the velocity, the upwind scheme might be a backward scheme (positive velocity, flow goes from left to right) or forward scheme (negative velocity, flow goes from right to left). The same goes for the south and north nodes. Have a look at the book "Numerical heat transfer and fluid flow" by S. Patankar, it is all in there. Cheers, Michujo.