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userfunctions:coulomb [2012/11/15 02:14] gag [General Description] |
userfunctions:coulomb [2015/11/26 15:50] gag [Examples] |
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==== General Informations ==== | ==== General Informations ==== | ||
- | * **USF Fortran File: | + | * **USF Fortran File: |
- | * **USF Name: | + | * **USF Name: |
- | * **Required Input Variable(s): | + | * **Required Input Variable(s): |
==== General Description ==== | ==== General Description ==== | ||
- | The file //USF_Sliding.f90// contains | + | The file '' |
- | The first user function (//Sliding_Weertman//) is a non-linear Weertman-type friction law and is described [[: | + | The first user function ('' |
| | ||
- | The friction law in // | + | The friction law in // |
- | < | + | < |
- | tau_b = C.N.[{ {X . ub^{-n} }/ {(1 + a.X^q)} }]^{1/n} . ub | + | where \\ |
- | </m> | + | < |
+ | and\\ | ||
+ | < | ||
- | Parameters: Friction Law Sliding Coefficient | + | The //Slip Coefficient// |
- | ! Friction Law Post-Peak Exponent | + | < |
- | ! Friction Law Maximum Value -> C ~ max bed slope | + | When < |
- | ! Friction Law Linear Velocity | + | |
- | ! | + | |
- | ! | + | The parameters to be given are:\\ |
- | ! Water Pressure (BC) (Compressive - positive) | + | * '' |
- | ! | + | * '' |
- | ! tau_b = C.N.[ X . ub^-n / (1 + a.X^q) ]^1/n . ub | + | * '' |
- | ! with a = (q-1)^(q-1) / q^q and X = ub / (C^n N^n As) | + | * '' |
- | ! | + | |
- | ! => Bdrag = C.N.[ X . ub^-n / (1 + a.X^q) ]^1/n | + | |
+ | The effective pressure is defined as < | ||
+ | |||
+ | |||
==== SIF contents ==== | ==== SIF contents ==== | ||
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Normal-Tangential Velocity = Logical True | Normal-Tangential Velocity = Logical True | ||
Flow Force BC = Logical True | Flow Force BC = Logical True | ||
+ | |||
+ | !! Water pressure given through the Stokes ' | ||
+ | !! (Negative = Compressive) | ||
+ | External Pressure = Equals Water Pressure | ||
+ | |||
Velocity 1 = Real 0.0 | Velocity 1 = Real 0.0 | ||
| | ||
Slip Coefficient 2 = Variable Coordinate 1 | Slip Coefficient 2 = Variable Coordinate 1 | ||
- | Real Procedure "./ | + | Real Procedure "ElmerIceUSF" " |
Slip Coefficient 3 = Variable Coordinate 1 | Slip Coefficient 3 = Variable Coordinate 1 | ||
- | Real Procedure "./ | + | Real Procedure "ElmerIceUSF" " |
| | ||
!! Parameters needed for the Coulomb Friction Law | !! Parameters needed for the Coulomb Friction Law | ||
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Friction Law Maximum Value = Real 1.0 !(C=1) | Friction Law Maximum Value = Real 1.0 !(C=1) | ||
Friction Law PowerLaw Exponent = Real 3.0 !(m = n = 3 Glen's law) | Friction Law PowerLaw Exponent = Real 3.0 !(m = n = 3 Glen's law) | ||
- | Friction Law Linear Velocity = Real 0.01 !(=1m/a dans un premier temps) | + | Friction Law Linear Velocity = Real 0.01 |
End | End | ||
</ | </ | ||
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==== Examples ==== | ==== Examples ==== | ||
- | An example | + | The Coulomb friction law is tested in '' |