====== COPO1 ======
===== Description =====
Constitutive law for boundary condition inpollutant transport analysis

==== The model ====
This law is only  used for linear thermal analysis of pollutant transport. This constitutive law takes account of transfer between the solid and the external world by convection.  The coefficients of convection are constant. Those coefficients induce a mix boundary condition on the diffusive flux. \\ This law is used with element [[elements:conra|CONRA]].

==== Files ====
Prepro: LCOPO.F \\
Lagamine: COPO1.F

===== Availability =====
|Plane stress state| YES |
|Plane strain state| YES |
|Axisymmetric state| NO |
|3D state| NO |
|Generalized plane state| YES |
===== Input file =====
==== Parameters defining the type of constitutive law ====
^ Line 1 (2I5, 60A1)^^
|IL|Law number|
|ITYPE| 123 |
|COMMENT| Any comment (up to 60 characters) that will be reproduced on the output listing|
==== Real parameters ====
^ Line 1 (7G10.0) ^^
|QNIN|real normal convection flow rate inside the medium|
|QNOUT|real normal convection flow rate at the injection point|
|DXP|characteristic length in velocity direction at the boundary|
|UR|real velocity convection in x direction inside the medium|
|VR|real velocity convection in y direction inside the medium|
|DIFFM|molecular diffusion coefficient inside the medium|
|ALONG|longitudinal dispersivity inside the medium|

===== Stresses =====
==== Number of stresses ====
2
==== Meaning (numerical, not physical) ====
|SIG(1)|time integrated for first upwind heat flow |
|SIG(2)|time integrated for second upwind heat flow|

===== State variables =====
==== Number of state variables ====
3
==== List of state variables ====
|Q(1)|temperature of the solid at the point under consideration |
|Q(2)|temperature of the external world $(=T_a)$ |
|Q(3)|meaningless |

N.B. DXP is the average length of the elements of solid in the velocity direction it is used (as ur, vr, diffm, along) only if upwind is acting and if ICAS≠4 in [[elements:conra|CONRA]] elements.

{{  :laws:plan_zeta_eta.png?600  |}}