Second order upwind is not UPwind!!!
http://www.kxcad.net/ansys/ANSYS_CFX.../i1311648.html
It is stated in the CFX theory (above link) that when one selects the high resolution scheme as below is the value at the upwind node. On the other hand when user selects the specified blend factor for (between 0 and 1), is equal to the average of the adjacent nodal gradients. I wanna know, this scheme is the upwind or central differencing scheme? http://my.fit.edu/itresources/manual...ug/node992.htm Where as in fluent user guide (above link) 2nd order upwind scheme is given by following formula is the gradient of in the upwind cell Both high resolution (CFX) and 2nd order upwind scheme (Fluent) are based on the principles by Barth and Jespersen [1] so that no new extrema is introduced in the solution, therfore monotonic behavior is preserved. 1. Does it mean that the high resolution scheme of CFX and 2nd order upwind scheme of fluent are equivalent. 2. Does it mean that the CFX 2nd order scheme is more like a baised 2nd order scheme with one term of upwind and 2nd term (anti diffusive term) is central differencing type? 3. Will 2nd order upwind (CFX definition) will make the solution worst than even 1st order upwind scheme? References: [1] Barth and Jespersen "The design and application of upwind schemes on unstructured meshes" . Technical Report AIAA890366, AIAA 27th Aerospace Sciences Meeting, Reno, Nevada, 1989. 
Dear frends and specially ghorrocks any help and comments please ?

It has been a while since I looked into this stuff, but this is my understanding:
Quote:
Quote:
Quote:


Quote:
So I cannot see anything which suggests beta=0.5 gives you CDS. 
Quote:

No, read the full sentence  the del (phi) is redefined in CDS, so the high res scheme cannot become the CDS as the del (phi) terms are different.

What about high resolution scheme? since this scheme does not guarantee the 2nd order upwind scheme every where.

This thread is getting tiresome. Please read the documentation.
It clearly says that the CDS has a different implementation to the upwinding schemes so you won't be able to get the CDS from any version of upwinding schemes  first order, hybrid or high res. 
All times are GMT 4. The time now is 17:13. 