## SV.DAT

### From BAWiki

## Contents

## Basic Information

### File-Type

sv.dat

### Version

1.x / July 2009

### Description-Date

January 2018

## Significance of the File

contains general input data for the program package SV (several models for settling velocity)

## File-Contents (in Catchwords)

**Input Steering Data**

- global parameters (block
**Global_Effects**)

- Selection of some global effects, acting on all active sediment fractions.
- key
**"Hindered_Settling"**: parameter for**Hindered Settling**:

- selector: perform computation with/without Hindered Settling.
- critical value
**Cgel**: sediment concentration in kg/m**3.

- Concerning Hindered Settling: Reduction of settling velocity for high concentrations is due to several interactions between sediment particles. According to Winterwerp
**Cgel**corresponds to a concentration, where a suspension becomes fluid mud. Typical value for**Cgel**is 80 kg/m**3. - Up to now (January 2018) Hindered_Settling can be combined with every sv model

- key "
**Flocculation**" : parameter for**formation and break-up of flocs**due to turbulence:

- selector: perform computation with/without flocculation.
- parameter
**WCA**: factor for floc formation.. - parameter
**WCB**: factor for floc break-up.

- Concerning Flocculation: Influence of formation as well as break-up of flocs on settling velocity is described through (
**1+WCA*G)/(1+WCB*G**2**). Typical values for**WCA**and**WCB**are 0.3 and 0.09. G is the absolute velocity gradient. - Turbulence Flocculation can be combined with the sv models "Constant", "Stokes", "Dietrich", "Power_Law" and "BAW_Approach". Using the models "Manning" or "vanRijn_1993" turbulence flocculation has no influence on the settling velocity.

- key "
**Power_Law_Exponent**" : parameter for**nonlinearity**of settling velocity in dependence on sediment concentration:

- parameter m: exponent for the power_law and BAW_approach model.

- Concerning the power law model: The influence of sediment concentration on settling velocity is given by
**k*C**m**. The faktor**k**can be prescribed individually for each sediment fraction. A typical value for**m**is 0.8.

- key "
**Max_Settling_Velocity**" : parameter to avoid high computed settling velocities. value unit is m/s. This parameter is optional. If not using this parameter the value 0.05 m/s will be used internally.

- key

- specific parameters for
**sediment fractions**(block**Sediment_Class**).

- key "
**Sediment_Name**" : name of**sediment class (fraction)**. - key "
**Density**" :**density**of sediment class in kg/m**3. - key "
**Diameter**" :**diameter**of sediment class in m. - key "
**Model_Type**" :**settling velocity model**:

**Constant**: use prescribed constant settling velocity (**Constant_SV**).**Stokes**: use constant settling velocity according to Stokes.**Dietrich**: use constant settling velocity according to Dietrich.**Power_Law**: compute settling velocity in dependence on sediment concentration (parameter**Power_Law_Constant**and**Power_Law_Exponent**) as well as the influence of flocculation (parameter**Flocculation**).**Manning**: compute settling velocity in dependence on sediment concentration as well as turbulent shear stress according to Manning.**BAW_Approach**: compute settling velocity in dependence on sediment concentration (parameter**Power_Law_Exponent**) as well as the influence of flocculation (parameter**Flocculation**).**BAW_Approach**is a specific**Power_Law**model. The sediment fraction dependent part of the settling velocity will be computed according to Dietrich.**vanRijn_1993**: compute settling velocity in dependence on sediment concentration according to vanRijn (1993). Need to set parameters in the block vanRijn_1993.

- Further informations according to
**Manning**can be found in (ca. 50 kB) Understanding the Sediment Transport Profile.

- (optional) key "
**Constant_SV**" :**constant settling velocity**in m/s for model**Constant**. - (optional) key "
**Power_Law_Constant**" :**factor**for model**Power_Law**. Typical value is 0.005.

- key "

- specific parameters for
**vanRijn_1993**model

- In this part the fraction independent parameters for vanRijn_1993 will be set
- This part is optional. It is necessary to use this part only if the vanRijn_1993 model will be used.
- Key "
**Flocculation_Constant**" : Parameter k [ws = k c**m] - Key "
**Flocculation_Exponent"**: Parameter m [ws = k c**m] - Key '
**Transition_Concentration'**: Limiting concentration cgr in g/l. If c is less or equal to cgr, the flocculation formulation will be used. If c is greater than cgr the hindered settling formulation will be used. - Key '
**HinderedSettling_Constant'**: Parameter alpha [ws = ws0 (1 - alpha c)**beta] - Key '
**HinderedSettling_Exponent'**: Parameter beta [ws = ws0 (1 - alpha c)**beta]

- Key "
- ws0 in the hindered settling formulation does not have to be specified by the user, because it is assumed that both formulations (flocculation and hindered settling) shall compute the same settling velocity for c equal to cgr. So ws0 can be computed as follows: ws0 = (k * cgr**m) / (1 - alpha * cgr)**beta

**General Remarks**

- While reading this steering data file the
**dictionary file sv_dico.dat**will be automatically accessed in directory**$PROGHOME/dic/**to support input.

## Programs using this Type of File

## Additional Information

### Language

Fortran90

### File-Form

FORMATTED

### File-Access

SEQUENTIAL

### File-Extension

.dat

### WRITE-Subroutine(s)/Module(s)

interactive generation, editor

### READ-Subroutine(s)/Module(s)

$PROGHOME/fortran/lib/sv/*/mod_m_sv_steer.f90

### Original Version

G. Lang, B. Fricke

### Maintenance

E. Rudolph, A. Sehili, H. Weilbeer

### Example-File

please refer to

- $PROGHOME/examples/lib/sv/sv.dat,
- $PROGHOME/examples/untrim2007/STD/sv.constant.en.std.dat,
- $PROGHOME/examples/untrim2007/STD/sv.dietrich.en.std.dat,
- $PROGHOME/examples/untrim2007/STD/sv.stokes.en.std.dat,
- $PROGHOME/examples/untrim2007/STD/sv.manning.en.std.dat, as well as
- $PROGHOME/examples/untrim2007/STD/sv.power_law.en.std.dat.

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