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 sameer mohrir August 11, 2000 03:24

Analysis of wake

Hello all,

What types of method are used for analysis of wake behind 2D / 3D bodies.

Best regards

 John C. Chien August 11, 2000 09:27

Re: Analysis of wake

(1). Jet and wake are in the same category. (2). Same method applies to the jet and wake. Both are free boundary layer type. (3). Schlichting's book "Boundary Layer Theory" has chapters dedicated to jet and wakes. It is the standard text book for graduate school students. (4). The turbulence model part is a different story. These models may not be applicable to all types of jets and wakes, without adjustment to the coefficients. (round jet, 2-D jet, etc...)

 Kai Kang August 11, 2000 09:35

Re: Analysis of wake

Checked out D. Wilcox, "Turbulence Modeling in CFD", there are examples (reviews) showing the different turbulence models applied to jet and wake

 John Cimbala August 11, 2000 09:51

Re: Analysis of wake

I did a comprehensive comparison of various turbulence models in the 2-D far wake. Overall, it turns out that NONE of the existing turbulence models does a great job on all aspects of the turbulent far wake. I presented my results at the 10th Symposium on Turbulent Shear Flows, August 1995, beginning on p. 6-25.

 sameer mohrir August 12, 2000 00:07

Re: Analysis of wake

Hello

Whether type of flow (i.e compressible / incompressible) will have an effect on wake formation behind any 2D / 3D bodies.

best regards

 John C. Chien August 12, 2000 00:36

Re: Analysis of wake

(1). Flow behind a 2-D or 3-D body is rather complex. (2). It is no longer in the conventional wake area. (3). Flow over a body can create a large oscillating separated flow region. And supersonic flow over a body can create a strong shock in front of the body. it will also create complex wave pattern in the separated flow region. (4). At most, the flow behind a body can be viewed as a near-wake problem, which is not conventional wake at all. In this case, far field region can be considered as the conventional wake region, where it has forgotten about the near field effect. (5). There is always a Mach number effect on jet and wake.

 sameer mohrir August 12, 2000 03:22

Re: Analysis of wake

Hello John C .Chien

Thanks

sameer mohrir

 Anders Hagberg September 5, 2000 11:05

Re: Analysis of wake

I have compared supersonic wakeflow with different turbulence modells. The RSM gave the best results, but it is still far a way from the correct solution.

Maybe you should try an Time- dependent solution

best reegards Anders Hagberg

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