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Upstream Boundary condition.

  • Jun 27 2022
  • kmartinezp

I have two questions about the Upstream boundary condition in FaSTMECH. The first Question is if it is possible to have two points of discharge entrance, I want to simulate the confluence of two streams. The second question is if it is possible to set a sediment load in entrance discharge, or is any way to introduce sediments.

Thank you so much for your answers.


  1. jmn says:

    Fastmech can handle more than one discharge input only when the two (or more) discharge can be crossed by a single upstream cross-section.Note that the cross-section need not cross perpendicularly to the channel, but you’ll need to set upstream flow conditions carefully (with appropriate angles). If the channels cannot be crossed by a single cross-section, then you should use a different model, such as Nay2dh or River2d. Fastmech assumes equilibrium load for sediment at the upstream end, but you can alter this by a multiplicative factor using the variable “Fraction of Equilibrium Load” to underload or overload the channel.


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