CMS-Flow Sediment Transport: Difference between revisions

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(Created page with "='''Transport Options'''= ==Sediment Transport== thumb|right|400px|SMS 10.1 | alt=SMS 10.1 The sediment transport controls are lo...")
 
(Created page with ='''Transport Options'''= ==Sediment Transport== thumb|right|400px|SMS 10.1 | alt=SMS 10.1 The sediment transport controls are lo...)
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The CMS card used to turn on or off the sediment transport is described in the table below.
The CMS card used to turn on or off the sediment transport is described in the table below.


{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description
! Card !! Arguments !! Default !! Range !! Description
|-
|-
| CALC_SEDIMENT_TRANSPORT || CHARACTER || OFF || ON <nowiki>|</nowiki> OFF || Turns on or off the sediment transport calculation.  
| CALC_SEDIMENT_TRANSPORT || CHARACTER || OFF || ON nowiki|/nowiki OFF || Turns on or off the sediment transport calculation.  
|}
|}


=== Transport model ===
=== Transport model ===
There  are currently three sediment transport models available in CMS: (1)  Equilibrium total load, (2) Equilibrium bed load plus  advection-diffusion for suspended load, and (3) Non-equilibrium total  load. The first two models are selected by unchecking the checkbox which  says "Use non-equilibrium transport" and selecting either "Total load" for the first model, or "Advection-diffusion" for the second next to  input item named "Formulation". The third model is selected by checking  the box "Use non-equilibrium transport".
There  are currently three sediment transport models available in CMS: (1)  Equilibrium total load, (2) Equilibrium bed load plus  advection-diffusion for suspended load, and (3) Non-equilibrium total  load. The first two models are selected by unchecking the checkbox which  says Use non-equilibrium transport and selecting either Total load  for the first model, or Advection-diffusion for the second next to  input item named Formulation. The third model is selected by checking  the box Use non-equilibrium transport.


{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description !! Versions
! Card !! Arguments !! Default !! Range !! Description !! Versions
|-
|-
| SED_TRAN_FORMULATION || CHARACTER || NET || WATANABE <nowiki>|</nowiki> LUND_CIRP <nowiki>|</nowiki> A-D <nowiki>|</nowiki> NET || Selects the sediment transport model. || >1.0
| SED_TRAN_FORMULATION || CHARACTER || NET || WATANABE nowiki|/nowiki LUND_CIRP nowiki|/nowiki A-D nowiki|/nowiki NET || Selects the sediment transport model. || 1.0
|-
|-
| SED_TRAN_CALC_INTERVAL || REAL ||  ||  greater or equal to hydro time step for explicit scheme, or equal  hydro  time step for implicit scheme || Time step used for transport  equation ||
| SED_TRAN_CALC_INTERVAL || REAL ||  ||  greater or equal to hydro time step for explicit scheme, or equal  hydro  time step for implicit scheme || Time step used for transport  equation ||
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==== 2. Equilibrium Bed load plus Advection-Diffusion Suspended Load====
==== 2. Equilibrium Bed load plus Advection-Diffusion Suspended Load====
Calculations  of suspended load and bed load are conducted separately. The bed load  is assumed to be in equilibrium and is included in the bed change  equation while the suspended load is solved through the solution of an  advection-diffusion equation. Actually the advection diffusion equation  is a non-equilibrium formulation, but because the bed load is assumed to  be in equilibrium, this model is referred to the "Equilibrium A-D" model.
Calculations  of suspended load and bed load are conducted separately. The bed load  is assumed to be in equilibrium and is included in the bed change  equation while the suspended load is solved through the solution of an  advection-diffusion equation. Actually the advection diffusion equation  is a non-equilibrium formulation, but because the bed load is assumed to  be in equilibrium, this model is referred to the Equilibrium A-D  model.


More information on the this model can be found [[CMS-Flow:Equilibrium Bed load plus AD Suspended load|'''here''']].
More information on the this model can be found [[CMS-Flow:Equilibrium Bed load plus AD Suspended load|'''here''']].
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# Van Rijn (1998)
# Van Rijn (1998)
# Watanabe (1987)
# Watanabe (1987)
# Soulsby-van Rijn (1997) (>=V4.0)
# Soulsby-van Rijn (1997) (=V4.0)


<br style="clear:both" />
br style=clear:both /
{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description
! Card !! Arguments !! Default !! Range !! Description
|-
|-
| NET_TRANSPORT_CAPACITY || CHARACTER || LUND-CIRP || LUND-CIRP <nowiki>|</nowiki> VAN_RIJN <nowiki>|</nowiki> WATANABE <nowiki>|</nowiki> SOULSBY || Selects the transport formula. Note that SOULSBY is only available in v>=4.0
| NET_TRANSPORT_CAPACITY || CHARACTER || LUND-CIRP || LUND-CIRP nowiki|/nowiki VAN_RIJN nowiki|/nowiki WATANABE nowiki|/nowiki SOULSBY || Selects the transport formula. Note that SOULSBY is only available in v=4.0
|-
|-
| TRANSPORT_FORMULA || CHARACTER || LUND-CIRP || LUND-CIRP <nowiki>|</nowiki> VAN_RIJN <nowiki>|</nowiki> WATANABE <nowiki>|</nowiki> SOULSBY || Selects the transport formula. Note that SOULSBY is only available in v>=4.0.
| TRANSPORT_FORMULA || CHARACTER || LUND-CIRP || LUND-CIRP nowiki|/nowiki VAN_RIJN nowiki|/nowiki WATANABE nowiki|/nowiki SOULSBY || Selects the transport formula. Note that SOULSBY is only available in v=4.0.
|-
|-
| SED_TRANS_FORMULATION || CHARACTER || LUND-CIRP || LUND-CIRP  <nowiki>|</nowiki> A-D <nowiki>|</nowiki> WATANABE <nowiki>|</nowiki> NET|| Selects the transport formula for the equilibrium total load model. Does not specify the transport formula for the equilibrium A-D and non-equilibrium total load models.
| SED_TRANS_FORMULATION || CHARACTER || LUND-CIRP || LUND-CIRP  nowiki|/nowiki A-D nowiki|/nowiki  WATANABE nowiki|/nowiki NET|| Selects the transport formula for the equilibrium total load model. Does not specify the transport formula for the equilibrium A-D and non-equilibrium total load models.
|-
|-
| CONCENTRATION_PROFILE || CHARACTER ||  LUND-CIRP||  LUND-CIRP<nowiki>|</nowiki>EXPONENTIAL<nowiki>|</nowiki> ROUSE<nowiki>|</nowiki> VAN_RIJN|| Selects the  concentration profile to be used either in the equilibrium A-D or total  load nonequilibrium models.
| CONCENTRATION_PROFILE || CHARACTER ||  LUND-CIRP||  LUND-CIRPnowiki|/nowikiEXPONENTIALnowiki|/nowiki  ROUSEnowiki|/nowiki VAN_RIJN|| Selects the  concentration profile to be used either in the equilibrium A-D or total  load nonequilibrium models.
|-
|-
| A_COEFFICIENT_WATANABE || REAL || 0.1 || 0.05-0.5 || Empirical coefficient which goes into the Watanabe transport formula. ||
| A_COEFFICIENT_WATANABE || REAL || 0.1 || 0.05-0.5 || Empirical coefficient which goes into the Watanabe transport formula. ||
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==== Transport Scaling Factors ====
==== Transport Scaling Factors ====
The  bed and suspended transport scaling factors multiply directly by the  transport capacity or near-bed sediment concentration calculated from  the transport formula. These factors should be used to calibrate  sediment transport rates and due to the large uncertainty in the  transport formula, it is generally acceptable to use scaling factors in  the range of 0.5-2.0.
The  bed and suspended transport scaling factors multiply directly by the  transport capacity or near-bed sediment concentration calculated from  the transport formula. These factors should be used to calibrate  sediment transport rates and due to the large uncertainty in the  transport formula, it is generally acceptable to use scaling factors in  the range of 0.5-2.0.
<br style="clear:both" />
br style=clear:both /
{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description
! Card !! Arguments !! Default !! Range !! Description
|-
|-
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==== Morphologic Scaling Factor ====
==== Morphologic Scaling Factor ====
The  morphologic scaling factor is directly multiplied by the calculated bed  change at every time step and is intended as a means of speeding up the  computational time. It is only recommended for periodic boundary  conditions or conditions that do not change rapidly over time.
The  morphologic scaling factor is directly multiplied by the calculated bed  change at every time step and is intended as a means of speeding up the  computational time. It is only recommended for periodic boundary  conditions or conditions that do not change rapidly over time.
<br style="clear:both" />
br style=clear:both /
{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description
! Card !! Arguments !! Default !! Range !! Description
|-
|-
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=== Sediment Characteristics ===
=== Sediment Characteristics ===
{| border="1"
{| border=1
!  Card !! Arguments !! Default !! Range !! Description !! Versions
!  Card !! Arguments !! Default !! Range !! Description !! Versions
|-
|-
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| SEDIMENT_DENSITY|| REAL  || 2650  || none  || Sets the sediment density in kg/m^3 ||  
| SEDIMENT_DENSITY|| REAL  || 2650  || none  || Sets the sediment density in kg/m^3 ||  
|-
|-
| SEDIMENT_FALL_VELOCITY || REAL  || none  || 4.0e-4 - 0.4  || Sets the sediment fall velocity to a constant in m/s  || v>=3.5
| SEDIMENT_FALL_VELOCITY || REAL  || none  || 4.0e-4 - 0.4  || Sets the sediment fall velocity to a constant in m/s  || v=3.5
|}
|}


=== Bedslope term ===
=== Bedslope term ===
{|  border="1"
{|  border=1
!  Card !! Arguments !! Default !! Range !!  Description !! Versions
!  Card !! Arguments !! Default !! Range !!  Description !! Versions
|-
|-
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=== Advanced ===
=== Advanced ===


{| border="1"
{| border=1
! Card !! Arguments !! Default !! Range !! Description !! Versions
! Card !! Arguments !! Default !! Range !! Description !! Versions
|-
|-
| HIDING_EXPOSURE_COEFFICIENT || REAL || 0.7 || 0.6-1.0 || Hiding and exposure coefficient. || v>=3.5
| HIDING_EXPOSURE_COEFFICIENT || REAL || 0.7 || 0.6-1.0 || Hiding and exposure coefficient. || v=3.5
|-
|-
| SCHMIDT_NUMBER || REAL ||  1.0 || none || Controls the sediment mixing strength || v>=4.0
| SCHMIDT_NUMBER || REAL ||  1.0 || none || Controls the sediment mixing strength || v=4.0
|}
|}


=== Boundary and Initial Conditions ===
=== Boundary and Initial Conditions ===
{| border="1"
{| border=1
! Card !! Arguments !! Default  !! Range !! Description !! Versions
! Card !! Arguments !! Default  !! Range !! Description !! Versions
|-
|-
| NET_LOADING_FACTOR || REAL || 1.0 || 0.5-2.0 || Used to  specify under- or overloading at sediment inflow boundaries. Only for  NET. || 3.5=>v<=4.0
| NET_LOADING_FACTOR || REAL || 1.0 || 0.5-2.0 || Used to  specify under- or overloading at sediment inflow boundaries. Only for  NET. || 3.5=v=4.0
|-
|-
|  SEDIMENT_INFLOW_LOADING_FACTOR ||  REAL || 1.0 || 0.5-2.0 || Used to  specify under- or overloading at  sediment inflow boundaries. || >=4.0
|  SEDIMENT_INFLOW_LOADING_FACTOR ||  REAL || 1.0 || 0.5-2.0 || Used to  specify under- or overloading at  sediment inflow boundaries. || =4.0
|-
|-
|  CALC_MORPH_DURING_RAMP || CHARACTER|| ON  || ON <nowiki>|  </nowiki> OFF || Determines whether to  calculate the morphology  change during the ramp period || v>=3.5
|  CALC_MORPH_DURING_RAMP || CHARACTER|| ON  || ON nowiki|  /nowiki OFF || Determines whether to  calculate the morphology  change during the ramp period || v=3.5
|}
|}

Revision as of 21:02, 15 January 2011

Transport Options

Sediment Transport

SMS 10.1
SMS 10.1

The sediment transport controls are located in the Transport section of the CMS-Flow Model Control window as shown in the figure below. The sediment transport is activated by going to the Transport section of the CMS-Flow Model Control and checking the box labeles Calculate sediment transport. The CMS card used to turn on or off the sediment transport is described in the table below.

Card Arguments Default Range Description
CALC_SEDIMENT_TRANSPORT CHARACTER OFF /nowiki OFF Turns on or off the sediment transport calculation.

Transport model

There are currently three sediment transport models available in CMS: (1) Equilibrium total load, (2) Equilibrium bed load plus advection-diffusion for suspended load, and (3) Non-equilibrium total load. The first two models are selected by unchecking the checkbox which says Use non-equilibrium transport and selecting either Total load for the first model, or Advection-diffusion for the second next to input item named Formulation. The third model is selected by checking the box Use non-equilibrium transport.

Card Arguments Default Range Description Versions
SED_TRAN_FORMULATION CHARACTER NET /nowiki LUND_CIRP nowiki|/nowiki A-D nowiki|/nowiki NET Selects the sediment transport model. 1.0
SED_TRAN_CALC_INTERVAL REAL greater or equal to hydro time step for explicit scheme, or equal hydro time step for implicit scheme Time step used for transport equation
MORPH_UPDATE_INTERVAL REAL greater or equal to hydro time step for explicit scheme, or equal hydro time step for implicit scheme Time step used for updating bed elevation

Note that the when selecting the equilibrium total load model, the SED_TRAN_FORMULATION card is set to either WATANABE or LUND_CIRP depending on the transport formula chosen. When selecting the equilibrium A-D model, the transport formula is specified through the concentration profile formula (described below).


1. Equilibrium Total load

In this model, both the bed load and suspended load are assumed to be in equilibrium. The bed change is solved using a simple mass balance equation known as the Exner equation. More information on the this model can be found here.

2. Equilibrium Bed load plus Advection-Diffusion Suspended Load

Calculations of suspended load and bed load are conducted separately. The bed load is assumed to be in equilibrium and is included in the bed change equation while the suspended load is solved through the solution of an advection-diffusion equation. Actually the advection diffusion equation is a non-equilibrium formulation, but because the bed load is assumed to be in equilibrium, this model is referred to the Equilibrium A-D model.

More information on the this model can be found here.

3. Non-equilibrium Total Load

The non-equilibrium sediment transport algorithm (NET) simulates non-cohesive, single size sediment transport and bed change using a Finite Volume method and includes advection, diffusion, hiding and exposure, and avalanching. NET sediment transport is calculated with a non-equilibrium bed-material (total load) formulation. In this approach, the suspended- and bed-load transport equations are combined into a single equation and thus there is one less empirical parameter to estimate (adaptation length).

Additional information on NET can be found here.

All of the previously mentioned models account for hard bottom and effect of the bed slope on bed load.

Transport Formula

The nearbed sediment concentation or concentration capacity are calculated with one of the following transport formula:

  1. Lund-CIRP (2006)
  2. Van Rijn (1998)
  3. Watanabe (1987)
  4. Soulsby-van Rijn (1997) (=V4.0)

br style=clear:both /

Card Arguments Default Range Description
NET_TRANSPORT_CAPACITY CHARACTER LUND-CIRP /nowiki VAN_RIJN nowiki|/nowiki WATANABE nowiki|/nowiki SOULSBY Selects the transport formula. Note that SOULSBY is only available in v=4.0
TRANSPORT_FORMULA CHARACTER LUND-CIRP /nowiki VAN_RIJN nowiki|/nowiki WATANABE nowiki|/nowiki SOULSBY Selects the transport formula. Note that SOULSBY is only available in v=4.0.
SED_TRANS_FORMULATION CHARACTER LUND-CIRP /nowiki A-D nowiki|/nowiki WATANABE nowiki|/nowiki NET Selects the transport formula for the equilibrium total load model. Does not specify the transport formula for the equilibrium A-D and non-equilibrium total load models.
CONCENTRATION_PROFILE CHARACTER LUND-CIRP /nowikiEXPONENTIALnowiki|/nowiki ROUSEnowiki|/nowiki VAN_RIJN Selects the concentration profile to be used either in the equilibrium A-D or total load nonequilibrium models.
A_COEFFICIENT_WATANABE REAL 0.1 0.05-0.5 Empirical coefficient which goes into the Watanabe transport formula.

Scaling Factors

Transport Scaling Factors

The bed and suspended transport scaling factors multiply directly by the transport capacity or near-bed sediment concentration calculated from the transport formula. These factors should be used to calibrate sediment transport rates and due to the large uncertainty in the transport formula, it is generally acceptable to use scaling factors in the range of 0.5-2.0. br style=clear:both /

Card Arguments Default Range Description
BED_LOAD_SCALE_FACTOR REAL 1.0 0.5-2.0 Calibration factor for bed load transport capacity formula
SUSP_LOAD_SCALE_FACTOR REAL 1.0 0.5-2.0 Calibration factor for suspended load transport capacity formula

Morphologic Scaling Factor

The morphologic scaling factor is directly multiplied by the calculated bed change at every time step and is intended as a means of speeding up the computational time. It is only recommended for periodic boundary conditions or conditions that do not change rapidly over time. br style=clear:both /

Card Arguments Default Range Description
MORPH_ACCEL_FACTOR REAL 1.0 1-100 Morphologic acceleracion factor. Directly multiplies by calculated bed change.

Sediment Characteristics

Card Arguments Default Range Description Versions
SEDIMENT_POROSITY REAL 0.4 0-1 Sets the sediment porosity
SEDIMENT_DENSITY REAL 2650 none Sets the sediment density in kg/m^3
SEDIMENT_FALL_VELOCITY REAL none 4.0e-4 - 0.4 Sets the sediment fall velocity to a constant in m/s v=3.5

Bedslope term

Card Arguments Default Range Description Versions
SLOPE_COEFFICIENT REAL 1.0 0-5 Bed slope coefficient which controls enters a diffusion term which moves sediment down slope

Advanced

Card Arguments Default Range Description Versions
HIDING_EXPOSURE_COEFFICIENT REAL 0.7 0.6-1.0 Hiding and exposure coefficient. v=3.5
SCHMIDT_NUMBER REAL 1.0 none Controls the sediment mixing strength v=4.0

Boundary and Initial Conditions

Card Arguments Default Range Description Versions
NET_LOADING_FACTOR REAL 1.0 0.5-2.0 Used to specify under- or overloading at sediment inflow boundaries. Only for NET. 3.5=v=4.0
SEDIMENT_INFLOW_LOADING_FACTOR REAL 1.0 0.5-2.0 Used to specify under- or overloading at sediment inflow boundaries. =4.0
CALC_MORPH_DURING_RAMP CHARACTER ON /nowiki OFF Determines whether to calculate the morphology change during the ramp period v=3.5
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