Hello everyone,
In SWMM Reference Manual Vol 2-Hydraulics, page 45: They said that SWMM 5 use an implicit method.- Please tell me why Bentley called it "Explicit solver" in SewerGEMS.- Is there a document detailed on different between Implicit solver and Explicit solver?- I have read the Bentley's Guide : "The implicit solver tends to be more stable with pumping situations. The explicit solver tends to be more stable with fast changing areas such as ponds or control structures"But if my model has both elements (pumping station and pond, control structures, etc.), what should I rely on to choose the right solver?
Hi CappelaJust adding some thoughts to Jesse´s answer:
- Please tell me why Bentley called it "Explicit solver" in SewerGEMS
It is called explicit solver, due the fact that this solver uses explicit methods to solve the Saint Venant equations, on the SWMM solver implicit methods. I guess the main differences will be that for the explicit solver the size of the time step must observe the Courant stability condition and you cannot use the Simplified Saint-Venant Equations.When using the SWMM, you can set up smaller time steps and still keep the numerical stability, besides that you can run several simplified Saint-Venant routing:
And by dampening the inertial terms you could get a behaviour very similar to the Diffusive WaveYou can learn more on these links:https://blog.virtuosity.com/sewergems-solvers-part1-choosing-the-right-solver
https://blog.virtuosity.com/sewergems-solvers-part2-choosing-the-right-solver-wastewater-systems