Hi,

We are a group of university students using MIKE 21 software for our capstone design project. We're trying to model a breakwater using the Weir function within the module, however, we are unsure if we are setting up our weir correctly. We are using Weir formula 1, and you can see our parameters in the attached picture. Is the width defined in the weir parameters perpendicular or parallel to the flow? As well, should the invert be negative so that the weir is going into the water and reaches the seabed?

We are finding that even though we are implementing this weir, we are not seeing significant changed in the results for the Hydrodynamic module, and Sand Transport module. Is there an output parameter that most effectively shows the erosion? What are typical values to see for rate of bed level change? Our scale is giving us a very large range. Also, we're not currently running the model for a long period of time, would it be beneficial to run it for a longer period?

Thank you!