Impinging_jet<\/em>: jet impinging on a flat plate.<\/li>\n<\/ul>\nThe original simulations for Backwardstep<\/em>, Ra_10p8<\/em> and Impinging_jet<\/em> did not converge, the aim was to fix the convergence issue. The remaining cases – i.e. Case3<\/em> and Channel_flow_flux_pitched<\/em> – were already converging. The objective was to enhance the convergence. The Case3 test case was particularly slow.<\/p>\nThe results obtained with each of these cases are reported in the following table containing results with and without the use the EGA.<\/p>\n
\n\n\n <\/td>\n | Without EGA<\/td>\n | With EGA<\/td>\n<\/tr>\n |
\nCase3<\/td>\n | 582 iterations<\/td>\n | 322 iterations<\/td>\n<\/tr>\n |
\nChannel_flow_flux_pitched<\/td>\n | 187 iterations<\/td>\n | 186 iterations<\/td>\n<\/tr>\n |
\nBackwardstep<\/td>\n | No Convergence<\/td>\n | 269 iterations<\/td>\n<\/tr>\n |
\nRa_10p8<\/td>\n | No Convergence<\/td>\n | 857 iterations<\/td>\n<\/tr>\n |
\nImpinging_jet<\/td>\n | No Convergence<\/td>\n | 405 iterations<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n The EGA was also tested with the following set of unsteady test cases:<\/p>\n \n- Ra_10p10<\/em><\/strong>:<\/strong> natural convection in a rectangular cavity at a Rayleigh number of 1010<\/sup>;<\/li>\n
- Network_smart<\/em><\/strong>:<\/strong> two-phase flow through a network of pipes;<\/li>\n
- Ra_10p5<\/em><\/strong> (Windows only):<\/strong> natural convection modelling in a square cavity at a Rayleigh number of 105<\/sup> using a compressible flow;<\/li>\n
- CapillaryTube<\/em><\/strong>:<\/strong> capillary tube flow;<\/li>\n
- Elbow_Water_Annulus<\/em><\/strong>:<\/strong> two-phase upward flow in an elbow with water air coming in at the centre of the pipe and water in an annulus around air inflow.<\/li>\n<\/ul>\n
The original simulations for CapillaryTube<\/em>, Elbow_Water_Annulus<\/em> and Ra_10p5<\/em> (Windows only) did not converge. For the Ra_10p5<\/em> case, no known set of parameters making it converge was found until then on Windows whereas it converged on Linux with the hypre solver (not available on Windows). Network_smart<\/em> crashed after running a few time-steps due to the time-step becoming too small. The Ra_10p10<\/em> test case is already converging but not optimally.<\/p>\nThe results obtained for each of these cases are reported in the following table containing results with and without the use the EGA.<\/p>\n \n\n\n <\/td>\n | Without EGA<\/strong><\/td>\nWith EGA<\/strong><\/td>\n<\/tr>\n\nTime step<\/strong><\/td>\nPhysical time<\/strong><\/td>\nTime step<\/strong><\/td>\nPhysical time<\/strong><\/td>\n<\/tr>\n\nRa_10p10<\/strong><\/td>\n10000<\/td>\n | 49.73s<\/td>\n | 10000<\/td>\n | 170.8s<\/td>\n<\/tr>\n | \nNetwork_smart<\/strong><\/td>\nCrash<\/td>\n | 5614<\/td>\n | 1s<\/td>\n<\/tr>\n | \nRa_10p5(Windows)<\/strong><\/td>\nNo Convergence<\/td>\n | 500<\/td>\n | 2.384s<\/td>\n<\/tr>\n | \nCapillaryTube<\/strong><\/td>\nNo Convergence<\/td>\n | 439<\/td>\n | 0.5s<\/td>\n<\/tr>\n | \nElbow Water Annulus<\/strong><\/td>\nNo Convergence<\/td>\n | 15272<\/td>\n | 0.3292s<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nDiscussion<\/h2>\nIn all cases the EGA was able to find fitter sets of parameters. With the EGA, test cases that were crashing were made to converge and the ones that already converged were made to converge faster.<\/p>\n | | | | | | | | | | | | |