SMS:FESWMS Material Properties

FESWMS material properties include roughness, turbulence, and wind/wave parameters. The Materials Properties dialog is accessed through the FESWMS menu.

Roughness Parameters

FESWMS Material Properties dialog showing the Roughness Parameters tab

The roughness helps determine the energy losses as water flows over elements. Each material includes roughness information.

• Manning n values (n1, n2, depth1, depth2)

The primary roughness property is the manning n value associated with the element. The manning n value can vary with depth by specifying n values at two depths. The n1 value is used below depth1. The n2 value is used above depth2. Between depth1 and depth2 the n value is linearly interpolated.

• Wall roughness

The wall roughness is used on the edge of the model domain. Wall roughness is ignored unless the model is using semi-slip boundaries.

• Soil Liners

FESWMS can be used with materials representing a soil liner. To use a liner, turn on the linear critical shear stress and set the value. When using a liner n1, n2, depth1, and depth2 are ignored.

• Pressure flow

It is required to toggle on "potential pressure flow" with all materials that are assigned to elements with a ceiling elevation. If pressure flow is enabled, the deck roughness is the manning value for the bridge deck. Otherwise deck roughness is ignored.

• Chezy

Chezy values are an alternative to using Manning n values for roughness. It's necessary to turn on chezy in the model parameters to use this value.

• Bed critical shear stress

The bed critical shear stress is used to compute clear water scour.

Turbulence Parameters

FESWMS Material Properties dialog showing the Turbulence Parameters tab

Turbulence parameters are used to control the energy lost in turbulence.

• Vo

Base eddy viscosity in Length^2/second

• Cu1, Cu2

Turbulence model coefficients used to modify base eddy viscosity

• Eddy diffusivity

Used to modify base eddy viscosity and is related to the amount of curves in the channel

• Storativity depth

The global storativity depth (specified in the model parameters) can be overriden on a material level by entering a non-zero value.

Wind/Wave Parameters

• Wind Shear Reduction Factor
• Water Wave Height
• Wave Period

FESWMS Material Properties dialog showing the Wind/Wave Parameters tab

Related Topics

• FESWMS Menu