LORENE
binary_omega_ana_xcts.C
1 /*
2  * Methods of class Binary_xcts to set analytical value to omega
3  * (see file binary_xcts.h for documentation)
4  */
5 
6 /*
7  * Copyright (c) 2010 Michal Bejger
8  *
9  * This file is part of LORENE.
10  *
11  * LORENE is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2
13  * as published by the Free Software Foundation.
14  *
15  * LORENE is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with LORENE; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  *
24  */
25 
26 char binary_omega_ana_xcts_C[] = "$Header: /cvsroot/Lorene/C++/Source/Binary_xcts/binary_omega_ana_xcts.C,v 1.2 2014/10/13 08:52:45 j_novak Exp $" ;
27 
28 /*
29  * $Id: binary_omega_ana_xcts.C,v 1.2 2014/10/13 08:52:45 j_novak Exp $
30  * $Log: binary_omega_ana_xcts.C,v $
31  * Revision 1.2 2014/10/13 08:52:45 j_novak
32  * Lorene classes and functions now belong to the namespace Lorene.
33  *
34  * Revision 1.1 2010/05/04 07:35:54 m_bejger
35  * Initial version
36  *
37  * $Header: /cvsroot/Lorene/C++/Source/Binary_xcts/binary_omega_ana_xcts.C,v 1.2 2014/10/13 08:52:45 j_novak Exp $
38  *
39  */
40 
41 // Headers C
42 #include "math.h"
43 
44 // Headers Lorene
45 #include "binary_xcts.h"
46 #include "unites.h"
47 
48 
49 namespace Lorene {
51 
52  using namespace Unites ;
53 
54  double rr = separation() ;
55  double mtot = star1.mass_g() + star2.mass_g() ;
56 
57  // Compacity factor
58  double compact = ggrav * mtot / rr ;
59 
60  double omega2 ;
61 
62  if ( star1.is_irrotational() ) {
63 
64  // Irrotational case
65  // -----------------
66 
67  assert( star2.is_irrotational() ) ;
68 
69  omega2 = ggrav * mtot / pow(rr, 3)
70  * (1. - 2.75 * compact + 8.625 * compact*compact ) ;
71 
72  }
73  else{ // Corotating case
74  // ---------------
75 
76  assert( !star2.is_irrotational() ) ;
77 
78  // a0/R
79  double a0sr = star1.ray_eq() / rr ;
80 
81  // Rescaled moment of inertia 5 I / (2 M a0^2)
82  double ired = double(5)/double(3) * ( 1. - double(6) / M_PI / M_PI ) ;
83  omega2 = ggrav * mtot / pow(rr, 3)
84  * (1. - compact * ( 2.75 + 2.*a0sr*a0sr * ired
85  - 0.48*pow(a0sr, 4) * ired*ired )
86  + compact*compact * ( 8.625 + 2.75*a0sr*a0sr * ired
87  + 2.*pow(a0sr, 4) * ired*ired ) ) ;
88 
89  }
90 
91  omega = sqrt( omega2 ) ;
92 
93  // The derived quantities are obsolete:
94  del_deriv() ;
95 
96 }
97 }
Star_bin_xcts star2
Second star of the system.
Definition: binary_xcts.h:69
void analytical_omega()
Sets the orbital angular velocity to some 2-PN analytical value (Keplerian value in the Newtonian cas...
Star_bin_xcts star1
First star of the system.
Definition: binary_xcts.h:66
double separation() const
Returns the coordinate separation of the two stellar centers [r_unit].
Definition: binary_xcts.C:434
void del_deriv() const
Deletes all the derived quantities.
Definition: binary_xcts.C:146
double omega
Angular velocity with respect to an asymptotically inertial observer.
Definition: binary_xcts.h:80
bool is_irrotational() const
Returns true for an irrotational motion, false for a corotating one.
Definition: star.h:1317
virtual double mass_g() const
Gravitational mass.
double ray_eq() const
Coordinate radius at , [r_unit].
Definition: star_global.C:108
Cmp sqrt(const Cmp &)
Square root.
Definition: cmp_math.C:220
Cmp pow(const Cmp &, int)
Power .
Definition: cmp_math.C:348
Lorene prototypes.
Definition: app_hor.h:64
Standard units of space, time and mass.