The Proceedings Fifth International Conference on Numerical Ship Hydrodynamics (1990) / Chapter Skim
Currently Skimming:
Large Eddy Simulation by Using Finite-Difference Method
Large Eddy Simulation by Using Finite-Difference Method
Pages 285-294
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 285... ...
After that, several pilot tests are performed with respect to a turbulent channel f low, in order to investigate the ef feet of the numerical dissipation terms on the turbulent f low structures. Turbulent f low structures in turbulent channel flows can be well simulated by using the 3rd order upwind difference scheme .
|
From page 286... ...
2.3 Representation of SGS Reynolds Stresses, Leonard Term and Cross Term SGS Reynolds stresses are modeled as follows introducing SGS eddy viscosity K
|
From page 287... ...
The derivatives in the momentum equations are discretized by 4th order centered difference approximations except for the convective terms. For the convective terms, following 3rd order upwind difference approximation is used in order to stabilize the computation, The first term of eq.(22)
|
From page 288... ...
In Kodama's calculation, 4-th order artificial dissipation terms were also added to the momentum equations in order to stabilize the calculation. Kodama analyzed the truncation errors and indicated that the artificial dissipation terms were so small that the accuracy of the solution was not degraded by them.
|
From page 289... ...
The contour lines shown in Figs.6, 7 are the convection terms, artificial dissipation terms, the SGS model terms(Leonard, Cross and SGS Reynolds terms) and the viscous terms on xl-x3 plane.
|
From page 290... ...
[13] Doi, Y., Kimura, T.: Large-Eddy Simulation of Turbulent Channel Flow, J
|
From page 291... ...
~ ~ ~ ~ ~ , , , , . , -o.oo ~o.oo 80.oo t20.oo I eo oo 200.oo 240.00 Yt + Exp.(Clark Re =1300)
|
From page 292... ...
~ ~ d) Fig.6-a Contour lines of each term in the stream Fig.6-b Same as Fig.6-a wise momentum equation on x1-x3 plane, a =0.06, y+=22.2, t=10, Re =500, a =0.03, y =22.2, t=9.5, Re =500, e: convection terms interval 50, e: convection terms interval 50, b:artificial dissipation terms interval 2 b:artificial dissipation terms interval 2 c:SGS model terms interval 2, d:viscous c:SGS model terms interval 2, d:viscous terms interval 10 terms interval 10 Fig.7-a Same as Fig.6-a a=0.03, y =250, t=9.5, Re =500, e: convection terms interval 50, b:artificial dissipation terms interval c:SGS model terms interval 2, d:~7~scous terms interval 10 292 b r:~-~-^O~: C)
|
From page 293... ...
h) d .~ ~=f~= f~ r Fig.8-a Contour lines of each term in the stream wise momentum equation calculated by Euler method, ~ =0.15, y =22.2, t=9.5, Re =500, ~ a:convection terms interval 50, o b:artificial dissipation terms interval 5 c:SGS model terms interval 5, d:viscous terms interval 10 o 1 1.
|
From page 294... ...
00 240. 00 Y~ Fig.ll Turbulence intensities calculated by ;~;ttit;~,' ~ ~ ~ ~ ~ ~ {< .~`t.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.