diff --git a/examples/EAGLE_100/eagle_100.yml b/examples/EAGLE_100/eagle_100.yml
index 3bcda091bdac5b740f3568de9c0814cc84c3b846..5275f709c710d2da1d5396e98f1d4d918e482c6d 100644
--- a/examples/EAGLE_100/eagle_100.yml
+++ b/examples/EAGLE_100/eagle_100.yml
@@ -49,6 +49,7 @@ Gravity:
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
minimal_temperature: 100 # (internal units)
diff --git a/examples/EAGLE_12/eagle_12.yml b/examples/EAGLE_12/eagle_12.yml
index 367c5f769775d9293c0ec7b0bf670a2b22dcb328..90070f6a342d60d48d8fd2c794014f9d638030be 100644
--- a/examples/EAGLE_12/eagle_12.yml
+++ b/examples/EAGLE_12/eagle_12.yml
@@ -47,6 +47,7 @@ Gravity:
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
minimal_temperature: 100 # (internal units)
diff --git a/examples/EAGLE_25/eagle_25.yml b/examples/EAGLE_25/eagle_25.yml
index cab0dbcd5efc0528ddc65a6dde1e5c2d7cb6b9a9..3d7d5de4fe2c98a04c986840bc2804edaf780c17 100644
--- a/examples/EAGLE_25/eagle_25.yml
+++ b/examples/EAGLE_25/eagle_25.yml
@@ -54,6 +54,7 @@ Gravity:
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
minimal_temperature: 100 # (internal units)
diff --git a/examples/EAGLE_50/eagle_50.yml b/examples/EAGLE_50/eagle_50.yml
index 35f7c85993d6d52189eaa1da35821fc5fa103c56..8d622998c5ea1c754e877643e42ee3d97bfa720e 100644
--- a/examples/EAGLE_50/eagle_50.yml
+++ b/examples/EAGLE_50/eagle_50.yml
@@ -49,6 +49,7 @@ Gravity:
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
minimal_temperature: 100 # (internal units)
diff --git a/examples/EAGLE_6/eagle_6.yml b/examples/EAGLE_6/eagle_6.yml
index e80fac8167a832c17cd10e1d2ae7cd854f314d17..fb885fa44f119bb3e296947997f71581d5ca0f48 100644
--- a/examples/EAGLE_6/eagle_6.yml
+++ b/examples/EAGLE_6/eagle_6.yml
@@ -58,6 +58,7 @@ Gravity:
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
minimal_temperature: 100 # (internal units)
diff --git a/examples/IsolatedGalaxy_starformation/isolated_galaxy.yml b/examples/IsolatedGalaxy_starformation/isolated_galaxy.yml
index d518732056f508cbf896dcd5f258663522a91eea..2a885f5770f88c3ee6dd75e194d0fa713160e39e 100644
--- a/examples/IsolatedGalaxy_starformation/isolated_galaxy.yml
+++ b/examples/IsolatedGalaxy_starformation/isolated_galaxy.yml
@@ -11,13 +11,13 @@ Gravity:
mesh_side_length: 32 # Number of cells along each axis for the periodic gravity mesh.
eta: 0.025 # Constant dimensionless multiplier for time integration.
theta: 0.7 # Opening angle (Multipole acceptance criterion).
- comoving_softening: 0.01 # Comoving softening length (in internal units).
- max_physical_softening: 0.01 # Physical softening length (in internal units).
+ comoving_softening: 0.01 # Comoving softening length (in internal units).
+ max_physical_softening: 0.01 # Physical softening length (in internal units).
# Parameters governing the time integration (Set dt_min and dt_max to the same value for a fixed time-step run.)
TimeIntegration:
time_begin: 0. # The starting time of the simulation (in internal units).
- time_end: 0.1 # The end time of the simulation (in internal units).
+ time_end: 0.1 # The end time of the simulation (in internal units).
dt_min: 1e-9 # The minimal time-step size of the simulation (in internal units).
dt_max: 1e-2 # The maximal time-step size of the simulation (in internal units).
@@ -35,20 +35,17 @@ Statistics:
# Parameters related to the initial conditions
InitialConditions:
- file_name: fid.hdf5 # The file to read
+ file_name: fid.hdf5 # The file to read
periodic: 0 # Are we running with periodic ICs?
# Parameters for the hydrodynamics scheme
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
- h_tolerance: 1e-4 # (Optional) Relative accuracy of the Netwon-Raphson scheme for the smoothing lengths.
- h_max: 10. # (Optional) Maximal allowed smoothing length in internal units. Defaults to FLT_MAX if unspecified.
- max_volume_change: 1.4 # (Optional) Maximal allowed change of kernel volume over one time-step.
- max_ghost_iterations: 30 # (Optional) Maximal number of iterations allowed to converge towards the smoothing length.
- minimal_temperature: 100 # (Optional) Minimal temperature (in internal units) allowed for the gas particles. Value is ignored if set to 0.
- H_ionization_temperature: 1e4 # (Optional) Temperature of the transition from neutral to ionized Hydrogen for primoridal gas.
+ h_min_ratio: 0.1 # Minimal smoothing in units of softening.
+ h_max: 10.
+# Standard EAGLE cooling options
EAGLECooling:
dir_name: ./coolingtables/ # Location of the Wiersma+08 cooling tables
H_reion_z: 11.5 # Redshift of Hydrogen re-ionization
diff --git a/examples/SantaBarbara/santa_barbara.yml b/examples/SantaBarbara/santa_barbara.yml
index eb20030e00c36646b4283012eab5ecae0e286680..aa478a29023af1945bdd8cf34ace1c421f249fc1 100644
--- a/examples/SantaBarbara/santa_barbara.yml
+++ b/examples/SantaBarbara/santa_barbara.yml
@@ -46,6 +46,7 @@ Gravity:
# Parameters of the hydro scheme
SPH:
resolution_eta: 1.2348 # "48 Ngb" with the cubic spline kernel
+ h_min_ratio: 0.1
CFL_condition: 0.1
initial_temperature: 1200. # (1 + z_ini)^2 * 2.72K
minimal_temperature: 100.
diff --git a/examples/SantaBarbara_low/santa_barbara.yml b/examples/SantaBarbara_low/santa_barbara.yml
index 0e3c66b1a1c1e04bf6fad30e806327b83f03737e..35a6e2762f91707ed43bd5f0107c3dd8a53e12e4 100644
--- a/examples/SantaBarbara_low/santa_barbara.yml
+++ b/examples/SantaBarbara_low/santa_barbara.yml
@@ -47,6 +47,7 @@ Gravity:
SPH:
resolution_eta: 1.2348 # "48 Ngb" with the cubic spline kernel
CFL_condition: 0.1
+ h_min_ratio: 0.1
initial_temperature: 1200. # (1 + z_ini)^2 * 2.72K
minimal_temperature: 100.
diff --git a/examples/SmallCosmoVolume/small_cosmo_volume.yml b/examples/SmallCosmoVolume/small_cosmo_volume.yml
index 32846227c93e7d747fade2dc306b4c5c5246c14f..e0d633079e941ade161b7e2fde0fbc063cbac254 100644
--- a/examples/SmallCosmoVolume/small_cosmo_volume.yml
+++ b/examples/SmallCosmoVolume/small_cosmo_volume.yml
@@ -30,6 +30,7 @@ Gravity:
# Parameters of the hydro scheme
SPH:
resolution_eta: 1.2348 # "48 Ngb" with the cubic spline kernel
+ h_min_ratio: 0.1
CFL_condition: 0.1
initial_temperature: 7075. # (1 + z_ini)^2 * 2.72K
minimal_temperature: 100.
diff --git a/examples/SmallCosmoVolume_VELOCIraptor/small_cosmo_volume.yml b/examples/SmallCosmoVolume_VELOCIraptor/small_cosmo_volume.yml
index d6b9a78fe3c2a891492affbdea9787d62916d3ed..15007ca8d39a328166a208a2d4cbbc6aea580009 100644
--- a/examples/SmallCosmoVolume_VELOCIraptor/small_cosmo_volume.yml
+++ b/examples/SmallCosmoVolume_VELOCIraptor/small_cosmo_volume.yml
@@ -30,6 +30,7 @@ Gravity:
# Parameters of the hydro scheme
SPH:
resolution_eta: 1.2348 # "48 Ngb" with the cubic spline kernel
+ h_min_ratio: 0.1
CFL_condition: 0.1
initial_temperature: 7075. # (1 + z_ini)^2 * 2.72K
minimal_temperature: 100.
diff --git a/examples/SmallCosmoVolume_cooling/small_cosmo_volume.yml b/examples/SmallCosmoVolume_cooling/small_cosmo_volume.yml
index bb4546659303a05aef1696fe4f2195031d9c035c..60046cadc3bd3af324b5f967c76315cf5a27fe52 100644
--- a/examples/SmallCosmoVolume_cooling/small_cosmo_volume.yml
+++ b/examples/SmallCosmoVolume_cooling/small_cosmo_volume.yml
@@ -30,6 +30,7 @@ Gravity:
# Parameters of the hydro scheme
SPH:
resolution_eta: 1.2348 # "48 Ngb" with the cubic spline kernel
+ h_min_ratio: 0.1
CFL_condition: 0.1
initial_temperature: 7075. # (1 + z_ini)^2 * 2.72K
minimal_temperature: 100.
diff --git a/examples/ZeldovichPancake_3D/zeldovichPancake.yml b/examples/ZeldovichPancake_3D/zeldovichPancake.yml
index a1d2342b56d6816c3cfbe7da70220ab244104fbd..6a7c5166635b7fa0ed5f69c41461d867c3b254ad 100644
--- a/examples/ZeldovichPancake_3D/zeldovichPancake.yml
+++ b/examples/ZeldovichPancake_3D/zeldovichPancake.yml
@@ -35,6 +35,7 @@ Statistics:
SPH:
resolution_eta: 1.2348 # Target smoothing length in units of the mean inter-particle separation
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
+ h_min_ratio: 0.1
# Parameters related to the initial conditions
InitialConditions:
diff --git a/examples/parameter_example.yml b/examples/parameter_example.yml
index dae922378b24614211e38cef22548cf0404ee196..39abf52c571bd65fb9904d7d66ffa662df8e0eec 100644
--- a/examples/parameter_example.yml
+++ b/examples/parameter_example.yml
@@ -28,6 +28,7 @@ SPH:
CFL_condition: 0.1 # Courant-Friedrich-Levy condition for time integration.
h_tolerance: 1e-4 # (Optional) Relative accuracy of the Netwon-Raphson scheme for the smoothing lengths.
h_max: 10. # (Optional) Maximal allowed smoothing length in internal units. Defaults to FLT_MAX if unspecified.
+ h_min_ratio: 0. # (Optional) Minimal allowed smoothing length in units of the softening. Defaults to 0 if unspecified.
max_volume_change: 1.4 # (Optional) Maximal allowed change of kernel volume over one time-step.
max_ghost_iterations: 30 # (Optional) Maximal number of iterations allowed to converge towards the smoothing length.
initial_temperature: 0 # (Optional) Initial temperature (in internal units) to set the gas particles at start-up. Value is ignored if set to 0.
diff --git a/src/cell.c b/src/cell.c
index bd1022f1fa23b5911c4056b602008601fa36ce68..4f44abd924be97e54e52fffda8559f7a0dcfe68a 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -3642,6 +3642,7 @@ void cell_drift_part(struct cell *c, const struct engine *e, int force) {
const double dim[3] = {e->s->dim[0], e->s->dim[1], e->s->dim[2]};
const int with_cosmology = (e->policy & engine_policy_cosmology);
const float hydro_h_max = e->hydro_properties->h_max;
+ const float hydro_h_min = e->hydro_properties->h_min;
const integertime_t ti_old_part = c->hydro.ti_old_part;
const integertime_t ti_current = e->ti_current;
struct part *const parts = c->hydro.parts;
@@ -3776,6 +3777,7 @@ void cell_drift_part(struct cell *c, const struct engine *e, int force) {
/* Limit h to within the allowed range */
p->h = min(p->h, hydro_h_max);
+ p->h = max(p->h, hydro_h_min);
/* Compute (square of) motion since last cell construction */
const float dx2 = xp->x_diff[0] * xp->x_diff[0] +
diff --git a/src/engine.c b/src/engine.c
index f32bc0dbe7e2346f9d15984575f1128a0b589d21..4a34112ca4b758768d3171fc49546a7f4d1e49de 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -2792,7 +2792,12 @@ void engine_init_particles(struct engine *e, int flag_entropy_ICs,
/* Update the softening lengths */
if (e->policy & engine_policy_self_gravity)
- gravity_update(e->gravity_properties, e->cosmology);
+ gravity_props_update(e->gravity_properties, e->cosmology);
+
+ /* Udpate the hydro properties */
+ if (e->policy & engine_policy_hydro)
+ hydro_props_update(e->hydro_properties, e->gravity_properties,
+ e->cosmology);
/* Start by setting the particles in a good state */
if (e->nodeID == 0) message("Setting particles to a valid state...");
@@ -3085,7 +3090,12 @@ void engine_step(struct engine *e) {
/* Update the softening lengths */
if (e->policy & engine_policy_self_gravity)
- gravity_update(e->gravity_properties, e->cosmology);
+ gravity_props_update(e->gravity_properties, e->cosmology);
+
+ /* Udpate the hydro properties */
+ if (e->policy & engine_policy_hydro)
+ hydro_props_update(e->hydro_properties, e->gravity_properties,
+ e->cosmology);
/* Trigger a tree-rebuild if we passed the frequency threshold */
if ((e->policy & engine_policy_self_gravity) &&
@@ -4088,7 +4098,7 @@ void engine_init(struct engine *e, struct space *s, struct swift_params *params,
int policy, int verbose, struct repartition *reparttype,
const struct unit_system *internal_units,
const struct phys_const *physical_constants,
- struct cosmology *cosmo, const struct hydro_props *hydro,
+ struct cosmology *cosmo, struct hydro_props *hydro,
const struct entropy_floor_properties *entropy_floor,
struct gravity_props *gravity, const struct stars_props *stars,
struct pm_mesh *mesh,
diff --git a/src/engine.h b/src/engine.h
index 5a9959a6a024b7e0d2ae85f63ce87302ebe9e0a7..938213d8c5b8889266e74e38f6fb2c00baa1d256 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -343,7 +343,7 @@ struct engine {
struct cosmology *cosmology;
/* Properties of the hydro scheme */
- const struct hydro_props *hydro_properties;
+ struct hydro_props *hydro_properties;
/* Properties of the entropy floor */
const struct entropy_floor_properties *entropy_floor;
@@ -419,7 +419,7 @@ void engine_init(struct engine *e, struct space *s, struct swift_params *params,
int policy, int verbose, struct repartition *reparttype,
const struct unit_system *internal_units,
const struct phys_const *physical_constants,
- struct cosmology *cosmo, const struct hydro_props *hydro,
+ struct cosmology *cosmo, struct hydro_props *hydro,
const struct entropy_floor_properties *entropy_floor,
struct gravity_props *gravity, const struct stars_props *stars,
struct pm_mesh *mesh,
diff --git a/src/gravity/Default/gravity.h b/src/gravity/Default/gravity.h
index d446844e8ffc862fd3be0688302ebb3a2efab8fa..6d1270c952100f3a25202fcdb22be09f9acaa8d9 100644
--- a/src/gravity/Default/gravity.h
+++ b/src/gravity/Default/gravity.h
@@ -40,7 +40,7 @@ __attribute__((always_inline)) INLINE static float gravity_get_mass(
}
/**
- * @brief Returns the softening of a particle
+ * @brief Returns the current co-moving softening of a particle
*
* @param gp The particle of interest
* @param grav_props The global gravity properties.
diff --git a/src/gravity/Potential/gravity.h b/src/gravity/Potential/gravity.h
index 10628dcea91786b0c7483134b8f7f844d6359e49..7d38e9126f1a313b169092b080ebc312c4bbe1bc 100644
--- a/src/gravity/Potential/gravity.h
+++ b/src/gravity/Potential/gravity.h
@@ -39,7 +39,7 @@ __attribute__((always_inline)) INLINE static float gravity_get_mass(
}
/**
- * @brief Returns the softening of a particle
+ * @brief Returns the current co-moving softening of a particle
*
* @param gp The particle of interest
* @param grav_props The global gravity properties.
diff --git a/src/gravity_properties.c b/src/gravity_properties.c
index e548e3010f3b46065a2510723b5bde97121b4c02..60c0bd05ba8cb2234284154b4383bec07f30756d 100644
--- a/src/gravity_properties.c
+++ b/src/gravity_properties.c
@@ -99,10 +99,11 @@ void gravity_props_init(struct gravity_props *p, struct swift_params *params,
}
/* Set the softening to the current time */
- gravity_update(p, cosmo);
+ gravity_props_update(p, cosmo);
}
-void gravity_update(struct gravity_props *p, const struct cosmology *cosmo) {
+void gravity_props_update(struct gravity_props *p,
+ const struct cosmology *cosmo) {
/* Current softening lengths */
double softening;
diff --git a/src/gravity_properties.h b/src/gravity_properties.h
index 0cabd9958efa2bb23524d03632f90fdd1f1c8306..09c8ef8ffa1d6cc4effa4895614106217a2861a9 100644
--- a/src/gravity_properties.h
+++ b/src/gravity_properties.h
@@ -73,7 +73,7 @@ struct gravity_props {
/*! Maxium physical softening */
double epsilon_max_physical;
- /*! Current sftening length */
+ /*! Current softening length */
float epsilon_cur;
/*! Square of current softening length */
@@ -90,7 +90,8 @@ void gravity_props_print(const struct gravity_props *p);
void gravity_props_init(struct gravity_props *p, struct swift_params *params,
const struct cosmology *cosmo, int with_cosmology,
int periodic);
-void gravity_update(struct gravity_props *p, const struct cosmology *cosmo);
+void gravity_props_update(struct gravity_props *p,
+ const struct cosmology *cosmo);
#if defined(HAVE_HDF5)
void gravity_props_print_snapshot(hid_t h_grpsph,
diff --git a/src/hydro_properties.c b/src/hydro_properties.c
index e83b90cdd932e2a61baaace72922025cf6e199f6..f14c88bfb5128c1da17590f50698e5d038734b71 100644
--- a/src/hydro_properties.c
+++ b/src/hydro_properties.c
@@ -30,12 +30,16 @@
#include "dimension.h"
#include "equation_of_state.h"
#include "error.h"
+#include "gravity_properties.h"
#include "hydro.h"
#include "kernel_hydro.h"
+#include "parser.h"
+#include "units.h"
#define hydro_props_default_max_iterations 30
#define hydro_props_default_volume_change 1.4f
#define hydro_props_default_h_max FLT_MAX
+#define hydro_props_default_h_min_ratio 0.f
#define hydro_props_default_h_tolerance 1e-4
#define hydro_props_default_init_temp 0.f
#define hydro_props_default_min_temp 0.f
@@ -104,6 +108,13 @@ void hydro_props_init(struct hydro_props *p,
p->h_max = parser_get_opt_param_float(params, "SPH:h_max",
hydro_props_default_h_max);
+ /* Minimal smoothing length ratio to softening */
+ p->h_min_ratio = parser_get_opt_param_float(params, "SPH:h_min_ratio",
+ hydro_props_default_h_min_ratio);
+
+ /* Temporarily set the minimal softening to 0. */
+ p->h_min = 0.f;
+
/* Number of iterations to converge h */
p->max_smoothing_iterations = parser_get_opt_param_int(
params, "SPH:max_ghost_iterations", hydro_props_default_max_iterations);
@@ -317,6 +328,7 @@ void hydro_props_print_snapshot(hid_t h_grpsph, const struct hydro_props *p) {
* @param p the struct
*/
void hydro_props_init_no_hydro(struct hydro_props *p) {
+
p->eta_neighbours = 1.2348;
p->h_tolerance = hydro_props_default_h_tolerance;
p->target_neighbours = pow_dimension(p->eta_neighbours) * kernel_norm;
@@ -325,6 +337,8 @@ void hydro_props_init_no_hydro(struct hydro_props *p) {
(pow_dimension(delta_eta) - pow_dimension(p->eta_neighbours)) *
kernel_norm;
p->h_max = hydro_props_default_h_max;
+ p->h_min = 0.f;
+ p->h_min_ratio = hydro_props_default_h_min_ratio;
p->max_smoothing_iterations = hydro_props_default_max_iterations;
p->CFL_condition = 0.1;
p->log_max_h_change = logf(powf(1.4, hydro_dimension_inv));
@@ -352,6 +366,20 @@ void hydro_props_init_no_hydro(struct hydro_props *p) {
p->diffusion.alpha_min = hydro_props_default_diffusion_alpha_min;
}
+/**
+ * @brief Update the global properties of the hydro scheme for that time-step.
+ *
+ * @param p The properties to update.
+ * @param gp The properties of the gravity scheme.
+ * @param cosmo The cosmological model.
+ */
+void hydro_props_update(struct hydro_props *p, const struct gravity_props *gp,
+ const struct cosmology *cosmo) {
+
+ /* Update the minimal allowed smoothing length */
+ p->h_min = p->h_min_ratio * gp->epsilon_cur;
+}
+
/**
* @brief Write a hydro_props struct to the given FILE as a stream of bytes.
*
diff --git a/src/hydro_properties.h b/src/hydro_properties.h
index c63ecd9af777b6420858ee2a732d3012c123b209..afc8a4b87aeb39f6bff1e61ae39edf391c856b1b 100644
--- a/src/hydro_properties.h
+++ b/src/hydro_properties.h
@@ -32,10 +32,14 @@
#endif
/* Local includes. */
-#include "parser.h"
-#include "physical_constants.h"
#include "restart.h"
-#include "units.h"
+
+/* Forward declarations */
+struct cosmology;
+struct swift_params;
+struct gravity_props;
+struct phys_const;
+struct unit_system;
/**
* @brief Contains all the constants and parameters of the hydro scheme
@@ -57,6 +61,12 @@ struct hydro_props {
/*! Maximal smoothing length */
float h_max;
+ /*! Minimal smoothing length expressed as ratio to softening length */
+ float h_min_ratio;
+
+ /*! Minimal smoothing length */
+ float h_min;
+
/*! Maximal number of iterations to converge h */
int max_smoothing_iterations;
@@ -131,6 +141,9 @@ void hydro_props_init(struct hydro_props *p,
const struct unit_system *us,
struct swift_params *params);
+void hydro_props_update(struct hydro_props *p, const struct gravity_props *gp,
+ const struct cosmology *cosmo);
+
#if defined(HAVE_HDF5)
void hydro_props_print_snapshot(hid_t h_grpsph, const struct hydro_props *p);
#endif
diff --git a/src/runner.c b/src/runner.c
index df8a52e2cae3f06fb4e59b1cfbce3cf20160f947..08f0432d81ecaef3fbbd4ffcca494868dad960dd 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -1230,6 +1230,7 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
const struct cosmology *cosmo = e->cosmology;
const struct chemistry_global_data *chemistry = e->chemistry;
const float hydro_h_max = e->hydro_properties->h_max;
+ const float hydro_h_min = e->hydro_properties->h_min;
const float eps = e->hydro_properties->h_tolerance;
const float hydro_eta_dim =
pow_dimension(e->hydro_properties->eta_neighbours);
@@ -1294,6 +1295,7 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
const float h_old = p->h;
const float h_old_dim = pow_dimension(h_old);
const float h_old_dim_minus_one = pow_dimension_minus_one(h_old);
+
float h_new;
int has_no_neighbours = 0;
@@ -1330,11 +1332,13 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
#endif
/* Skip if h is already h_max and we don't have enough neighbours */
- if ((p->h >= hydro_h_max) && (f < 0.f)) {
+ if (((p->h >= hydro_h_max) && (f < 0.f)) ||
+ ((p->h <= hydro_h_min) && (f > 0.f))) {
/* We have a particle whose smoothing length is already set (wants
- * to be larger but has already hit the maximum). So, just tidy up
- * as if the smoothing length had converged correctly */
+ * to be larger but has already hit the maximum OR wants to be smaller
+ * but has already reached the minimum). So, just tidy up as if the
+ * smoothing length had converged correctly */
#ifdef EXTRA_HYDRO_LOOP
@@ -1436,8 +1440,8 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
p->h = h_new;
}
- /* If below the absolute maximum, try again */
- if (p->h < hydro_h_max) {
+ /* If within the allowed range, try again */
+ if (p->h < hydro_h_max && p->h > hydro_h_min) {
/* Flag for another round of fun */
pid[redo] = pid[i];
@@ -1453,7 +1457,18 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
/* Off we go ! */
continue;
- } else {
+ } else if (p->h <= hydro_h_min) {
+
+ /* Ok, this particle is a lost cause... */
+ p->h = hydro_h_min;
+
+ /* Do some damage control if no neighbours at all were found */
+ if (has_no_neighbours) {
+ hydro_part_has_no_neighbours(p, xp, cosmo);
+ chemistry_part_has_no_neighbours(p, xp, chemistry, cosmo);
+ }
+
+ } else if (p->h >= hydro_h_max) {
/* Ok, this particle is a lost cause... */
p->h = hydro_h_max;
diff --git a/src/space.c b/src/space.c
index d930bcdcabada454c86719b66eb029f4e231d6b3..897554225e745819f9f9b9b1fc9c1e35d988713a 100644
--- a/src/space.c
+++ b/src/space.c
@@ -3351,6 +3351,10 @@ void space_first_init_parts_mapper(void *restrict map_data, int count,
const struct hydro_props *hydro_props = s->e->hydro_properties;
const float u_init = hydro_props->initial_internal_energy;
+ const float hydro_h_min_ratio = e->hydro_properties->h_min_ratio;
+
+ const struct gravity_props *grav_props = s->e->gravity_properties;
+ const int with_gravity = e->policy & engine_policy_self_gravity;
const struct chemistry_global_data *chemistry = e->chemistry;
const struct cooling_function_data *cool_func = e->cooling_func;
@@ -3360,6 +3364,12 @@ void space_first_init_parts_mapper(void *restrict map_data, int count,
if (p[k].h <= 0.)
error("Invalid value of smoothing length for part %lld h=%e", p[k].id,
p[k].h);
+
+ if (with_gravity) {
+ const struct gpart *gp = p[k].gpart;
+ const float softening = gravity_get_softening(gp, grav_props);
+ p->h = max(p->h, softening * hydro_h_min_ratio);
+ }
}
/* Convert velocities to internal units */