Tech Briefs
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.