Hi Mayank

Please explain more about your problem because this issue invites a lot of questions and we can launch a full-scale investigation on this issue in different aspects.

your question statement is not clear,  you looking for a case file of BFS or a code of k-w model ??

a case file of k-w model for 3D bfs or ahmed body problem or any other simple 3D geometry but "without" the application of energy equation.

Hi Mayank, I agree with Shrish that your question is not clear. There are two points to consider. (1) k-omega turbulence closure, (2) backward facing step. No. (2) is a problem for the Reynolds solver, No. 1 the closure used within the Reynolds solver. Regarding No. (1) I attach a file which might be of interest for you. Regards and a happy transition to 2015!

Hi Mayank

Please explain more about your problem because this issue invites a lot of questions and we can launch a full-scale investigation on this issue in different aspects.

Thanks a lot A.O Borisyuk sir. The link is very useful.

@Seyed and Helmut sir, i am working in a research group to develop an unstructured CFD solver. My seniors had already developed the K-w module for the same but validation part is required for 3D case. My work is to validate the code for any 3D problem (without using energy equation) like BFS, flow over an Ahmed body etc. and then to add energy equation to it. So, i was in need for a research article for validation purpose. 

@Helmut sir, the paper attached by you is interesting and useful. Thanks a lot.

Hi Mayank, I came across this question as I was looking for test cases to validate a turbulence model.

I was looking for a backward facing step experimental analysis problem. If you have anything similar would you please share?

Hi Mayank, try the attached file which contains some observations and semi-empirical modelling attempts, among them also k-eps. It would be nice if you could repeat these calculations with k-omega in the Re = \infty form derived in the paper I have sent you December 2014, where Karman turns out to be 1/sqrt(2*pi) = 0.399. I think that this form of k-omega should give the right answer for the re-attachment length at very high Re. I would have done it by myself but have no resources and more non-Newtonian problems. Have a nice day, and if you have nothing else to do then listen here: All men become brothers:

https://www.youtube.com/watch?v=kbJcQYVtZMo

I think that you need an experimental database for doing this. May be the database for a backward facing step from Driver&Seegmiller (1985) could be useful for you. It is a bit older database but quite useful for your purposes . These authors have measured mean velocities and its fluctuations, and there is data for the the reattachment length too. I carried out some work related to this topic when I developed my PhD project. You can see this reference (and others), and some turbulence model comparisons in my PhD work. I have uploaded my PhD thesis in Research Gate, and then, I think that you can download it. The name of the work is Theoretical - numerical study of flows with strong streamlines curvature, PhD Thesis ETSEIB, UPC Barcelona Spain. 

On the principle of independence of the boundary conditions of structure direction of turbulence

Lu Panming

Abstract

This is an introduction to the turbulence modeling theory of the present author, which can take the boundary conditions of turbulence structure into consideration ( the main contents have either not been published in normal journals or only published in chinese papers).   It is included that： (I)。Difficulty Problems Encountered in “Second-Moment-Closure” turbulence modelling ，i.e.  “Gao-Ge Anomaly” ;  (II)。The improvement  to the ”Second-Moment-Closure” turbulence modelling in order to allows the boundary conditions of turbulence structure direction could be prescribed;  (III)。An explanation to the principle of  independence  of  the boundary conditions of

turbulence structure direction ;  (IV)。Six suggestions to the possible future work directions;  (V)。 An explanation to the ”Gao-Ge Anomaly”.

------------------

4. The principle of the independence of the boundary conditions is not only to the turbulence modelling, but also suitable to the other subject, because it is frequently meet the equations are not easy to solve, so there is often a need of modelling or predigestion.  For example, both the D‘Alembert anomaly (~1752) and the Stokes anomaly (~1856), are due to breach the  principle of independence  of the boundary conditions, according to today`s point of view .This is because, first, by using the inviscid potential flow`s dynamic equations it is not possible to affiliate the slip-less condition of the real fluid at the wall, and  second, using the Stokes equation it is not possible to affiliate the boundary conditions both at the wall of cylinder and at the infinite to the cylinder.  The first anomaly lead to the discovery of the Prandlt`s boundary layer theory（1904）, and the  second anomaly  was solved by Oseen（1910）with introducing a modification. All these reflect the scientific worthiness and broad latency of the present principle   of the independence of the boundary conditions.

-----------------

above is an example paragraph,for more details or need the full text, please go to the end of this letter, where will be an web address existed.

http://staff.ustc.edu.cn/~pmlu/