ADINA News Group

The Solution of Large Fluid Flow Models in ADINA, continued

Much improved solution times have been achieved in our new
algebraic multi-grid solver. Please see the July 15, 2006 News.

In the September 28, 2004 News we showed two examples of large fluid flow models solved with the new FCBI fluid flow elements and a more efficient algebraic multi-grid (AMG) solver. We re-visit these problems here to show further solution times and show the solution of an additional problem.


The laminar turnaround duct
(see September 28, 2004 News)







The table below shows some further solution times obtained in double precision.

Number of 900 MHz processors Number of DOFs Total solution time Number of iterations Memory usage
1 9,343,980 15 h 219 2.8 GB
2 9,343,980 9 h 220 2.8 GB
1 15,081,768 29 h 227 4.5 GB
2 15,081,768 19 h 226 4.5 GB

Please see the July 15, 2006 News for much improved solution times.




The Manifold
(see September 28, 2004 News)





Number of 900 MHz processors Number of DOFs Total solution time Number of iterations Memory usage
1 19,295,350 39 h 143 4.1 GB
2 19,295,350 23 h 144 4.1 GB

Please see the July 15, 2006 News for much improved solution times.




Turbulent flow in a turning channel with rectangular cross section

Important benchmarks in turbulence modeling are the flows in turning channels. This type of flow is common in engineering equipment such as turbomachinery and propulsion systems. We present the flow predictions and a direct comparison with experimental results obtained in the 120° turning channel depicted below.







Following is a graphical summary of the numerical results obtained using the 201,150 DOFs mesh compared to experimental data. The prediction of the pressure coefficient Cp agrees quite well with the experimental data considering that the k-epsilon model was used.


Source of experimental data:
Brunn, H.H., "An Experimental Investigation of Secondary Flow Losses in Bends with Rectangular Cross Sections," CUED/A-Turbo/TR 95, Cambridge University.


Results obtained using four 900 MHz processors with double precision

Number of DOFs Total solution time Number of
iterations
Memory usage
201,150 0.1 h 78 46 MB
798,750 0.8 h 111 0.2 GB
3,171,150 5 h 174 0.7 GB
5,400,000 10 h 207 1.1 GB
8,022,300 13 h 209 1.7 GB

Please see the July 15, 2006 News for much improved solution times.

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