Version 2.8.2

• The block COUPLING_LATERAL has been updated. The parameter 'side_weir_fac' has been removed to reduce the number of parameters. Further, the parameter 'my_weir' has been renamed to 'c_m', denoting the De Marchi coefficent. Additionally, a sink-term for the momentum can be activated for flow leaving the 1D domain over the sideweir by selecting 'momentum_sink=yes'. The momentum sink does not affect the coupled 2D domain. Also, no momentum is added to the 1D domain if water flows from the 2D back into the 1D domain.
  
• The additional parameter 'suppressed_overfall' has been added to the block COUPLING_LATERAL with the options 'yes' or 'no' (Default: no). If 'suppressed_overfall' is set to 'yes', then the user-specified discharge coefficient is multiplied with an additional reduction factor. The reduction is calculated for a sharp crested weir according to Fig.8.10 in Aigner and Bollrich (2021).If the parameter is set to 'no', suppressed overfall conditions are not taken into account when calculating the lateral discharge over the weir.

Bugfixes

• VTK visualization (e.g. via "BASEviz") failed with an error message. This problem has been fixed together with other related issues (e.g. the visualization window can now be closed during simulation).
  
• A memory access issue that occurred when writing data to a CGNS file was fixed.
• When using "hot start" in BASEsub, the path to the continue-file was not used correctly by BASEMENT. This issue has been fixed.
• The graphical user-interface displayed incorrect warning for the tags 'strickler_factor' and 'roughness_factor', even when the tag 'grain_size_friction' was set to 'no'. This bug has been fixed.
  

New Features

• A new EXTERNAL_SOURCE type with the name 'sideweir' is available for the BASEchain module. The source term allows to model a lateral weir overflow. In addition to a source term for water mass, also a source term for momentum can be activated for this EXTERNAL_SOURCE type by selecting "momentum_sink=yes".
• A new EXTERNAL_SOURCE type with the name 'coupling_sideweir' is available for the BASEchain module. The source term allows to model a lateral weir overflow and linking it with another domain. In addition to a source term for water mass, also a source term for momentum can be activated for this EXTERNAL_SOURCE type by selecting "momentum_sink=yes".
• A new EXTERNAL_SOURCE type with the name 'bottom_opening' is available for the BASEchain module. The source term allows to model an outflow through the bottom of the river bed, e.g. through a Tyrolean weir. In addition to a source term for water mass, also a source term for momentum can be activated for this EXTERNAL_SOURCE type by selecting "momentum_sink=yes".
• Gravitational bed load transport (slope failures) in longitudinal direction (1D) has been implemented for the BASEchain module. The implemented geometric approach is based on the idea that a slope betweem two cross-sections is flattened if its angle becomes steeper than a given critical slope angle.
  

Bug-fixes

• The parallelization of BASEchain simulations has been improved. We recommend that users of the BASEchain module using more than one thread switch to this release.
  
• For the boundary condition type "IOup", but the transport rate of the individual grain classes in the first cross-section was not correctly written to output and monitoring files. This has been fixed.
  
• The default value of the parameter "zweir_fac_a" in the hydraulic bounary block was set 0.0 instead of 1.0. This affects the boundary conditions of type "weir", "coupling_weir", "gate", and "coupling_gate".
  
• If the cross sections in the original .bmg file are not in the same order as in the model definition (.bmc), writing the topo_restart.bmg file resulted in a crash. This has been fixed.

Known Issues

• Fixed bed starts eroding if both suspended load and bed load transport are activated if the suspended load is below transport capacity.
• Van Rijn formula does not result in any sediment being transported (1D-model).

General

• The new tag "eddy_viscosity_type" is now used to select either "dynamic" or "constant" eddy viscosity. By default, the type is "dynamic", so the type needs to be provided for simulations that use constant eddy viscosity. In addition, the tag "const_eddy_viscosity" has been renamed to "eddy_viscosity".
  

Known Issues

• The upstream and downstream stringdefs of the inner boundary weir must be of the same length, otherwise mass might not be conserved.