Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Tides Eccentricity Behavior Fix #1318

Merged
merged 4 commits into from
Jan 14, 2025
Merged

Tides Eccentricity Behavior Fix #1318

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
1a542ba
Modified tides to ignore terms quadratic in eccentricity, when they p…
veome22 Jan 7, 2025
fe9cf1e
updated changelog
veome22 Jan 7, 2025
85218cf
Merge branch 'dev' into tides_ecc_fix
veome22 Jan 14, 2025
c5d1d7f
clarified when the higher order terms should be ignored in the comments
veome22 Jan 14, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 14 additions & 3 deletions src/BaseBinaryStar.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1052,7 +1052,8 @@ double BaseBinaryStar::CalculateDEccentricityTidalDt(const DBL_DBL_DBL_DBL p_ImK
double R1_AU = radiusStar * RSOL_TO_AU;
double R1_over_a = R1_AU / m_SemiMajorAxis;
double R1_over_a_8 = R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a;


// No need to ignore quadratic e order terms during (super) synchronous rotation, since this formula is already linear in eccentricity
return -(3.0 / 4.0) * (m_Eccentricity / OrbitalAngularVelocity()) * (1.0 + (massCompanion / massStar)) * (G_AU_Msol_yr * massCompanion / R1_AU / R1_AU / R1_AU) * R1_over_a_8 * ((3.0 * ImK10 / 2.0) - (ImK12 / 4.0) - ImK22 + (49.0 * ImK32 / 4.0));
}

Expand Down Expand Up @@ -1080,8 +1081,11 @@ double BaseBinaryStar::CalculateDOmegaTidalDt(const DBL_DBL_DBL_DBL p_ImKlm, con
double R1_AU = radiusStar * RSOL_TO_AU;
double R1_over_a = R1_AU / m_SemiMajorAxis;
double R1_over_a_6 = R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a;
double e2_spin_term = (m_Eccentricity * m_Eccentricity) * ((ImK12 / 4.0) - (5.0 * ImK22) + (49.0 * ImK32 / 4.0));

return (3.0 / 2.0) * (1.0 / MoIstar) * (G_AU_Msol_yr * massCompanion * massCompanion / R1_AU) * R1_over_a_6 * (ImK22 + ((m_Eccentricity * m_Eccentricity) * ((ImK12 / 4.0) - (5.0 * ImK22) + (49.0 * ImK32 / 4.0))));
// if the star is rotating (super) synchronously AND quadratic 'e' terms cause the star to spin up further, ignore the higher order terms
if ((utils::Compare(p_Star->Omega(), OrbitalAngularVelocity()) > 0) && (utils::Compare((ImK22 + e2_spin_term), 0.0) > 0)){e2_spin_term = 0.0;}
return (3.0 / 2.0) * (1.0 / MoIstar) * (G_AU_Msol_yr * massCompanion * massCompanion / R1_AU) * R1_over_a_6 * (ImK22 + e2_spin_term);
}


Expand All @@ -1108,8 +1112,15 @@ double BaseBinaryStar::CalculateDSemiMajorAxisTidalDt(const DBL_DBL_DBL_DBL p_Im
double R1_AU = radiusStar * RSOL_TO_AU;
double R1_over_a = R1_AU / m_SemiMajorAxis;
double R1_over_a_7 = R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a * R1_over_a;
double e2_sma_term = (m_Eccentricity * m_Eccentricity) * ((3.0 * ImK10 / 4.0) + (ImK12 / 8.0) - (5.0 * ImK22) + (147.0 * ImK32 / 8.0));

// if the star is rotating (super) synchronously AND quadratic 'e' terms cause the star to spin up further, ignore the higher order terms.
// Note: here we use the SPIN e^2 terms (not the semi-major axis terms) to determine when to ignore the higher order terms in semi-major axis evolution.
// this is to ensure that the higher order terms are always consistently applied/ignored across the tidal evolution equations.
double e2_spin_term = (m_Eccentricity * m_Eccentricity) * ((ImK12 / 4.0) - (5.0 * ImK22) + (49.0 * ImK32 / 4.0));
if ((utils::Compare(p_Star->Omega(), OrbitalAngularVelocity()) > 0) && (utils::Compare((ImK22 + e2_spin_term), 0.0) > 0)){e2_sma_term = 0.0;}

return -(3.0 / OrbitalAngularVelocity()) * (1.0 + (massCompanion / massStar)) * (G_AU_Msol_yr * massCompanion / R1_AU / R1_AU) * R1_over_a_7 * (ImK22 + ((m_Eccentricity * m_Eccentricity) * ((3.0 * ImK10 / 4.0) + (ImK12 / 8.0) - (5.0 * ImK22) + (147.0 * ImK32 / 8.0))));
return -(3.0 / OrbitalAngularVelocity()) * (1.0 + (massCompanion / massStar)) * (G_AU_Msol_yr * massCompanion / R1_AU / R1_AU) * R1_over_a_7 * (ImK22 + e2_sma_term);
}


Expand Down
4 changes: 3 additions & 1 deletion src/changelog.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1427,7 +1427,9 @@
// - fix for issue #1317 - SN events not always logged in BSE SN file when evolving MS merger products
// - added code to ensure final BSE detailed output file TIMESTEP_COMPLETED record is always logged
// (may duplicate FINAL_STATE record, but logging TIMESTEP_COMPLETED is consistent, and it's what most people look for)
// 03.10.06 VK - Jan 13, 2025 - Enhancement:
// - Modified the KAPIL2024 tides to ignore quadratic 'e' terms (for spin and separation evolution) if they spin up an already synchronized star.

const std::string VERSION_STRING = "03.10.05";
const std::string VERSION_STRING = "03.10.06";

# endif // __changelog_h__
Loading