strot_diff_hydro.C

/*
 * Function Star_rot_diff::hydro_euler
 *
 * (see file star_rot_diff.h for documentation)
 *
 */

/*
 *   Copyright (c) 2025 Santiago Jaraba
 *
 *   This file is part of LORENE.
 *
 *   LORENE is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   LORENE is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with LORENE; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


// C headers
#include <cstdlib>

// Lorene headers
#include "star_rot_diff.h"
#include "utilitaires.h"

namespace Lorene {
void Star_rot_diff::hydro_euler(){

    int nz = mp.get_mg()->get_nzone() ; 
    int nzm1 = nz - 1 ; 

    // Computation of u_euler
    // ----------------------
    
    Scalar x(mp) ; 
    Scalar y(mp) ; 
    x = mp.x ; 
    y = mp.y ; 
    
    u_euler.set_etat_qcq() ; 
    
    // Cartesian components of differential rotation:

    u_euler.set(1) = - omega_field * y ;
    u_euler.set(2) =   omega_field * x ;
    u_euler.set(3) = 0 ;
    u_euler.annule_domain(nzm1) ; 
    
    u_euler.set_triad( mp.get_bvect_cart() ) ;  // Triad = Cartesian triad
    
    u_euler.std_spectral_base() ;   // sets the standard bases for spectral expansions

    u_euler = ( u_euler + beta ) / nn ; 

    u_euler.std_spectral_base() ;   // sets the standard bases for spectral expansions

//## Test
    Vector utest(mp, CON, mp.get_bvect_spher()) ; 
    utest.set_etat_qcq() ; 
    
    utest.set(1) = 0 ;      // Spherical components of differential rotation
    utest.set(2) = 0 ;
    utest.set(3) = ( omega_field - nphi ) / nn;

    utest.set(3).annule_domain(nzm1) ; 
    utest.set(3).std_spectral_base() ;
    utest.set(3).mult_rsint() ;     //  Multiplication by r sin(theta)
    
    utest.set_triad( mp.get_bvect_spher() ) ; 

    utest.change_triad( mp.get_bvect_cart() ) ; 
    
    for (int i=1; i<=3; i++) {
    const Valeur& uu = u_euler(i).get_spectral_va() ;
    Valeur& ut = utest.set(i).set_spectral_va() ;
    
    if (uu.get_etat() != ETATZERO) {
        uu.coef() ; 
        
        if (ut.get_etat() == ETATZERO) {
        ut.set_etat_cf_qcq() ;
        ut.c_cf = 0 ; 
        ut.c_cf->base = uu.c_cf->base ; 
        }
        else {
        ut.coef() ; 
        }
        
        Mtbl_cf diff = *(uu.c_cf) - *(ut.c_cf) ;
        cout << "Star_rot_diff::hydro_euler: test u_euler(" << i << ") : " 
         << max( abs(diff) )(0) << endl ; 
    
    }
    }
//##

    if ( (u_euler(1).get_etat() == ETATZERO) &&
     (u_euler(2).get_etat() == ETATZERO) &&
     (u_euler(3).get_etat() == ETATZERO) )    {
    
    for (int i=1; i<=3; i++) u_euler.set(i) = 0 ;    
    }


    // Computation of uuu (norme of u_euler)
    // ------------------

    // The scalar product is performed on the spherical components: 

    Vector us = u_euler ; 
    us.change_triad( mp.get_bvect_spher() ) ; 

    Scalar uuu2 =   a_car * ( us(1) * us(1) + us(2) * us(2) ) 
         +  b_car * us(3) * us(3) ; 

    uuu = sqrt( uuu2 ) ; 
    
    if (uuu.get_etat() == ETATQCQ) {
    uuu.set_spectral_base( us(3).get_spectral_base() ) ;   // Same basis as 
    }                          // (Omega -N^phi) r sin(theta)

    // Lorentz factor
    // --------------
    
    Scalar u2(mp) ; 
    u2 = unsurc2 * uuu2 ; 
    
    Scalar gam2 = 1 / (1 - u2) ; 
    
    gam_euler = sqrt(gam2) ; 

    gam_euler.std_spectral_base() ;  // sets the standard spectral bases for
                    // a scalar field

    //  Energy density E with respect to the Eulerian observer
    //------------------------------------
    
    ener_euler = gam2 * ( ener + press ) - press ; 

    ener_euler.std_spectral_base() ; 
    
    // Trace of the stress tensor with respect to the Eulerian observer
    //------------------------------------
    
    s_euler = 3 * press  +  ( ener_euler + press ) * u2  ;

    s_euler.std_spectral_base() ; 
    
    // The derived quantities are obsolete
    // -----------------------------------
    
    del_deriv() ;                
    

}
}