0002622: Reynolds Stress Mismatch - OpenFOAM Issue Tracking

ID	Project	Category	View Status	Date Submitted	Last Update

0002622	OpenFOAM	Feature	public	2017-07-20 06:04	2017-07-20 07:42

Reporter	mechkween	Assigned To	henry
Priority	urgent	Severity	major	Reproducibility	always
Status	closed	Resolution	fixed
Platform	GNU/Linux	OS	Other	OS Version	(please specify)

Summary	0002622: Reynolds Stress Mismatch
Description	Hi, I've tried asking this question everywhere but here without any success. This pertains to obtaining the Reynolds stresses from an OpenFOAM simulation. I see two ways of doing that, one by stating "on" for the prime2mean statistics for the "U" field and two, by using the command line (postProcess with -func R) where I provide the mean U, mean p, mean nut and mean phi fields for computations. The first is direct computation of the mean Reynolds stresses while the latter is the modeled Reynolds stress from the Boussinesq approximation. They should be equivalent since this approximation holds true for a RAS. But the values from both are way off from one another. The stress from "R" seems correct as I can verify the mean TKE from the solver which means prime2mean statistics do not provide the right answer. Could you tell me why this discrepancy exists? (TKE k = (t11 + t22 + t33)/2, where tii = diagonal Reynolds Stress component.) Thanks and Regards
Additional Information	Including image of plane showing tau_12 (xy component) from both methods. Similar differences observed in other Reynolds stresses.
Tags	No tags attached.

Date Modified	Username	Field	Change
2017-07-20 06:04	mechkween	New Issue
2017-07-20 06:04	mechkween	File Added: t12_cmp.jpg
2017-07-20 07:42	henry	Assigned To	=> henry
2017-07-20 07:42	henry	Status	new => closed
2017-07-20 07:42	henry	Resolution	open => fixed
2017-07-20 07:42	henry	Note Added: 0008417