From ec80cf2bf8d2c05b65959ad02810bd2788a43425 Mon Sep 17 00:00:00 2001
From: Matthieu Schaller <schaller@strw.leidenuniv.nl>
Date: Mon, 9 Mar 2020 16:06:59 +0000
Subject: [PATCH] Give a sensible DM softening also for runs without DM
---
examples/HydroTests/EvrardCollapse_3D/evrard.yml | 7 +++----
examples/Planetary/EarthImpact/earth_impact.yml | 7 +++----
src/gravity_properties.c | 6 ++++++
3 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/examples/HydroTests/EvrardCollapse_3D/evrard.yml b/examples/HydroTests/EvrardCollapse_3D/evrard.yml
index c14f9151b5..ab43864638 100644
--- a/examples/HydroTests/EvrardCollapse_3D/evrard.yml
+++ b/examples/HydroTests/EvrardCollapse_3D/evrard.yml
@@ -31,10 +31,9 @@ SPH:
# Parameters for the self-gravity scheme
Gravity:
- eta: 0.025 # Constant dimensionless multiplier for time integration.
- theta: 0.9
- comoving_softening: 0.001 # Comoving softening length (in internal units).
- max_physical_softening: 0.001 # Physical softening length (in internal units).
+ eta: 0.025 # Constant dimensionless multiplier for time integration.
+ theta: 0.7
+ max_physical_baryon_softening: 0.001 # Physical softening length (in internal units).
# Parameters related to the initial conditions
InitialConditions:
diff --git a/examples/Planetary/EarthImpact/earth_impact.yml b/examples/Planetary/EarthImpact/earth_impact.yml
index b1df0a6974..83aa4d027b 100644
--- a/examples/Planetary/EarthImpact/earth_impact.yml
+++ b/examples/Planetary/EarthImpact/earth_impact.yml
@@ -44,10 +44,9 @@ SPH:
# Parameters for the self-gravity scheme
Gravity:
- eta: 0.025 # Constant dimensionless multiplier for time integration.
- theta: 0.7 # Opening angle (Multipole acceptance criterion)
- comoving_baryon_softening: 0.003 # Comoving softening length (in internal units).
- max_physical_baryon_softening: 0.003 # Physical softening length (in internal units).
+ eta: 0.025 # Constant dimensionless multiplier for time integration.
+ theta: 0.7 # Opening angle (Multipole acceptance criterion)
+ max_physical_baryon_softening: 0.003 # Physical softening length (in internal units).
# Parameters for the task scheduling
Scheduler:
diff --git a/src/gravity_properties.c b/src/gravity_properties.c
index 6b21b20b8e..cd7a890917 100644
--- a/src/gravity_properties.c
+++ b/src/gravity_properties.c
@@ -151,6 +151,12 @@ void gravity_props_init(struct gravity_props *p, struct swift_params *params,
params, "Gravity:max_physical_baryon_softening");
}
+ /* Some gravity models use the DM softening as the one and only softening
+ length that exists. So, if we don't have DM (e.g. hydro test or planetary
+ physics), we must have a non-zero epsilon. */
+ if (!has_DM && has_baryons)
+ p->epsilon_DM_max_physical = p->epsilon_baryon_max_physical;
+
p->epsilon_DM_comoving = p->epsilon_DM_max_physical;
p->epsilon_baryon_comoving = p->epsilon_baryon_max_physical;
}
--
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