Transport theory

Include

For non-cohesive fractions, it is possible to select to include in the simulation either bed load or suspended load, or both. Corresponding transport theory must be defined accordingly.

Bed load

Bed load transport model

The following transport models are available for non-cohesive fractions:

·         Engelund-Hansen

·         van Rijn

·         Engelund-Fredsøe

·         Meyer-Peter & Muller

·         Adjustable Smart-Jaeggi

·         Yang - sand

·         Yang - gravel

·         Wilcock & Crowe

·         Parker

·         Ackers & White

Bed load factor

A bed load factor is applied to the selected transport formula. It is a simple multiplication factor applied to the calculated transport rate. The default neu­tral value is 1, and values can vary between 0.5 and 2.0. Beyond this range the validity of the chosen formula could be questioned.

Suspended load

Suspended load transport model

The following transport models are available for non-cohesive fractions:

·         Engelund-Hansen

·         van Rijn

·         Engelund-Fredsøe

·         Meyer-Peter & Muller

·         Adjustable Smart-Jaeggi

·         Yang - sand

·         Yang - gravel

·         Garcia & Parker

·         Ackers & White

·         Lane-Kalinske

Suspended load factor

A suspended load factor is applied to the selected transport formula. It is a simple multiplication factor applied to the calculated transport rate. The default neutral value is 1, and values can vary between 0.5 and 2.0. Beyond this range the validity of the chosen formula could be questioned.

Additional parameters for the Adjustable Smart-Jaeggi formula

When the Adjustable Smart-Jaeggi formula is selected for the non-cohesive fraction, the following parameters are also required, for both bed load and suspended load.

d90/d30

Describes the uniformity of sediments for the faction.

Angle of repose

The angle of repose is specified here.

Slope dependency

The slope dependency is either defined as a function of the bed slope or the water surface slope.

Shields stress

The Shields stress is either defined as total or skin friction.

Coefficients and exponents

Parameters a1 to a8 are coefficients and exponents used in the Smart-Jaeggi formula. Refer to the MIKE 1D reference manual for more detailed informa­tion.

Suspended load, global values

The following global parameters are required for cohesive fractions. Global values are applied throughout all calculation points in the river network, unless local values have been defined.

Exponent

The exponent used in the erosion equation, from MIKE 1D reference manual.

Erosion shear stress limit

The erosion shear stress limit is specified here.

Erosion coefficient

The erosion coefficient used in the erosion equation, from MIKE 1D reference manual.

Deposition shear stress limit

The deposition shear stress limit is specified here.

Suspended load, local values

Local values may be specified in the table. Local values are applied at spe­cific locations defined by Branch name and Chainage.