SMS:RMA2 Boundary Conditions: Difference between revisions

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[[Category:RMA2|Boundary Conditions]]
[[Category:RMA2|Boundary Conditions]]
[[Category:SMS Dialogs|R]]
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Revision as of 15:39, 4 February 2014

Assigning Boundary Conditions

Boundary conditions are generally defined on nodestrings but may also be defined on nodes. The default boundary condition is a closed boundary (no flow).

Deleting Boundary Conditions

Nodal Boundary Conditions

File:RMA2 Nodal BC.jpg
RMA2 Nodal Boundary Conditions dialog

Boundary Condition Type

  • None

No Boundary Condition is assigned to this Nodestring

  • Water Surface Elevation

A Water surface elevation BC is assigned to this Nodestring. This boundary condition is normally located at the tailwater location. However. RMA2 does sometime edit the water depth at the exit boundary to satisfy the finite element equations.

  • Velocity Components
  • Unit Flowrate
  • No Slip Condition

Boundary Angle

  • Specify Flow Direction
  • Perpendicular into Boundary
  • Perpendicular out of Boundary
  • Specified angle

Optional Parameters

  • Water Density
  • Include in node summary file

Boundary Condition Value

  • Constant
  • Transient

Nodestring Boundary Conditions

File:RMA2 Assign BC.jpg
RMA2 Nodestring Boundary Conditions dialog

Boundary Condition Type

  • None

No Boundary Condition is assigned to this Nodestring

  • Specified Flow Rate

A flow rate BC is assigned to this nodestring. It is the most popular way to provide a total flow across a particular continuity line. The total flow (cubic units per second), flow angle (degrees from positive x-axis) and distribution factor can be specified.

DisFactors.JPG
  • Water Surface Elevation

A Water surface elevation BC is assigned to this Nodestring. This boundary condition is normally located at the tailwater location. (However RMA2 does sometime edit the water depth at the exit boundary to satisfy the finite element equations)

  • Reflecting Boundary

Considered an advanced feature – for more information see the "Boundary Permeability (Reflection/Absorption)" section on page 99 of the Users Guide to RMA2 version 4.5

  • Rating Curve

A Rating curve can also be defined by selecting the Options... button

Flowrate

  • Constant
  • Transient

Boundary Refelction

  • Steady state water surface
  • Tidal storage surface area

Flow Direction

  • Degree CCW from positive X axis
  • Perpendicular to boundary

Advanced Options

  • Make this nodestring the "Total Flow" nodestring
  • Specify vorticity

Flow Distribution

Related Topics

RMA2