These three graphs show how the number of iterations to solve the St. Venant equation in SWMM 5 changes during the course of the simulation based on rapidly changing inflow, steady inflow and decreasing inflow. This example allows up to ten iterations and a tighter head tolerance to better illustrate how the number of iterations increase at the beginning of the simulation and during rapid inflow. Normally, in SWMM 5 the number of iterations will be between a minimum of 2 and a maximum of 4 iterations.
In the first graph the outflow is in blue and the number of iterations at each time step is shown in red. In the second graph the bubble size is based on the number of iterations and the y axis is outflow of the network. The third graph shows the number of iterations used at each link in the model at a particular time step. The more the flow changes the more iterations are needed to keep the flow in balance.
![Reblog this post [with Zemanta]](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_t_inpLP-DCYie2O7Ynl-Y3RCgHYxNlTr0XvXns8Pml4g8_TaJoM3vo7jg4Rd6nQil4NMIM9uPJSRWJrTPRr-c5r4xn-PWwDs2__onIi5jo-0UocLbcX5WsMVGBpKIrTl2AaMROfzfgbBYOArDYYYA=s0-d)
In the first graph the outflow is in blue and the number of iterations at each time step is shown in red. In the second graph the bubble size is based on the number of iterations and the y axis is outflow of the network. The third graph shows the number of iterations used at each link in the model at a particular time step. The more the flow changes the more iterations are needed to keep the flow in balance.
