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Changeset 11512 for NEMO/branches/2019/dev_r10984_HPC-13_IRRMANN_BDY_optimization/doc/latex/NEMO/subfiles/chap_conservation.tex – NEMO

Ignore:
Timestamp:
2019-09-09T12:05:20+02:00 (5 years ago)
Author:
smasson
Message:

dev_r10984_HPC-13 : merge with trunk@11511, see #2285

File:
1 edited

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  • NEMO/branches/2019/dev_r10984_HPC-13_IRRMANN_BDY_optimization/doc/latex/NEMO/subfiles/chap_conservation.tex

    r11263 r11512  
    88\chapter{Invariants of the Primitive Equations} 
    99\label{chap:Invariant} 
    10 \minitoc 
     10\chaptertoc 
    1111 
    1212The continuous equations of motion have many analytic properties. 
     
    3535The alternative is to use diffusive schemes such as upstream or flux corrected schemes. 
    3636This last option was rejected because we prefer a complete handling of the model diffusion, 
    37 \ie of the model physics rather than letting the advective scheme produces its own implicit diffusion without 
     37\ie\ of the model physics rather than letting the advective scheme produces its own implicit diffusion without 
    3838controlling the space and time structure of this implicit diffusion. 
    3939Note that in some very specific cases as passive tracer studies, the positivity of the advective scheme is required. 
     
    122122This properties is satisfied locally with the choice of discretization we have made (property (II.1.9)~). 
    123123In addition, when the equation of state is linear 
    124 (\ie when an advective-diffusive equation for density can be derived from those of temperature and salinity) 
     124(\ie\ when an advective-diffusive equation for density can be derived from those of temperature and salinity) 
    125125the change of horizontal kinetic energy due to the work of pressure forces is balanced by the change of 
    126126potential energy due to buoyancy forces: 
     
    283283In discrete form, all these properties are satisfied in $z$-coordinate (see Appendix C). 
    284284In $s$-coordinates, only first order properties can be demonstrated, 
    285 \ie the vertical momentum physics conserve momentum, potential vorticity, and horizontal divergence. 
     285\ie\ the vertical momentum physics conserve momentum, potential vorticity, and horizontal divergence. 
    286286 
    287287% ------------------------------------------------------------------------------------------------------------- 
     
    294294the heat and salt contents are conserved (equations in flux form, second order centred finite differences). 
    295295As a form flux is used to compute the temperature and salinity, 
    296 the quadratic form of these quantities (\ie their variance) globally tends to diminish. 
     296the quadratic form of these quantities (\ie\ their variance) globally tends to diminish. 
    297297As for the advective term, there is generally no strict conservation of mass even if, 
    298298in practice, the mass is conserved with a very good accuracy.  
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