Tweaked entropy switch parameters for GizmoMFM. It works, but results are not great.

src/hydro/GizmoMFM/hydro.h

@@ -697,17 +697,20 @@ __attribute__((always_inline)) INLINE static void hydro_kick_extra(
     p->conserved.momentum[2] += dt_grav * p->conserved.mass * a_grav[2];
 
     /* apply the entropy switch */
+    const float psize = powf(p->geometry.volume / hydro_dimension_unit_sphere,
+                             hydro_dimension_inv);
     const float dEgrav = p->conserved.mass *
                          sqrtf(a_grav[0] * a_grav[0] + a_grav[1] * a_grav[1] +
                                a_grav[2] * a_grav[2]) *
-                         cosmo->a_inv * p->h;
-    if (p->conserved.energy < const_entropy_switch_ekin_fac *
-                                  (p->force.Ekinmax + p->conserved.energy) ||
+                         cosmo->a_inv * psize;
+    const float dEkin = 0.5f * p->conserved.mass * p->force.Ekinmax;
+    if (p->conserved.energy <
+            const_entropy_switch_ekin_fac * (dEkin + p->conserved.energy) ||
         p->conserved.energy < const_entropy_switch_grav_fac * dEgrav) {
       p->conserved.energy = hydro_one_over_gamma_minus_one *
                             p->conserved.entropy * pow_gamma_minus_one(p->rho);
-      if (p->conserved.energy < const_entropy_switch_ekin_fac *
-                                    (p->force.Ekinmax + p->conserved.energy)) {
+      if (p->conserved.energy <
+          const_entropy_switch_ekin_fac * (dEkin + p->conserved.energy)) {
         hydro_add_flag(p, GIZMO_FLAG_EKIN_SWITCH);
       }
       if (p->conserved.energy < const_entropy_switch_grav_fac * dEgrav) {

src/hydro/GizmoMFM/hydro_flag_variable.h

@@ -38,7 +38,7 @@ enum gizmo_flag_variables {
  * @param p Particle.
  */
 __attribute__((always_inline)) INLINE static void hydro_flag_variable_init(
-    struct part *p) {
+    struct part* p) {
   p->flag_variable = 0;
 }
 
@@ -50,9 +50,10 @@ __attribute__((always_inline)) INLINE static void hydro_flag_variable_init(
  * @param num_fields The number of i/o fields to write.
  */
 __attribute__((always_inline)) INLINE static void hydro_write_flag_variable(
-  const struct part* parts, struct io_props* list, int* num_fields) {
+    const struct part* parts, struct io_props* list, int* num_fields) {
 
-  list[*num_fields] = io_make_output_field("FlagVariable", INT, 1, UNIT_CONV_NO_UNITS, parts, flag_variable);
+  list[*num_fields] = io_make_output_field(
+      "FlagVariable", INT, 1, UNIT_CONV_NO_UNITS, parts, flag_variable);
   ++(*num_fields);
 }
 
@@ -62,8 +63,8 @@ __attribute__((always_inline)) INLINE static void hydro_write_flag_variable(
  * @param p Particle.
  * @param value Flag value to add.
  */
-__attribute__((always_inline)) INLINE static void hydro_add_flag(
-  struct part* p, int value) {
+__attribute__((always_inline)) INLINE static void hydro_add_flag(struct part* p,
+                                                                 int value) {
 
   p->flag_variable |= (1 << value);
 }
@@ -76,7 +77,7 @@ __attribute__((always_inline)) INLINE static void hydro_add_flag(
  * @param p Particle.
  */
 __attribute__((always_inline)) INLINE static void hydro_flag_variable_init(
-    struct part *p) {}
+    struct part* p) {}
 
 /**
  * @brief Add the flag variable to the snapshot output.
@@ -86,7 +87,7 @@ __attribute__((always_inline)) INLINE static void hydro_flag_variable_init(
  * @param num_fields The number of i/o fields to write.
  */
 __attribute__((always_inline)) INLINE static void hydro_write_flag_variable(
-  const struct part* parts, struct io_props* list, int* num_fields) {}
+    const struct part* parts, struct io_props* list, int* num_fields) {}
 
 /**
  * @brief Add the given flag value to the flag variable.
@@ -94,8 +95,8 @@ __attribute__((always_inline)) INLINE static void hydro_write_flag_variable(
  * @param p Particle.
  * @param value Flag value to add.
  */
-__attribute__((always_inline)) INLINE static void hydro_add_flag(
-  struct part* p, int value) {}
+__attribute__((always_inline)) INLINE static void hydro_add_flag(struct part* p,
+                                                                 int value) {}
 
 #endif
 

src/hydro/GizmoMFM/hydro_iact.h

@@ -261,17 +261,12 @@ __attribute__((always_inline)) INLINE static void runner_iact_fluxes_common(
     vmax = 0.0f;
 
   /* calculate flux limiter quantities */
-  const float Wjminvi[3] = {Wj[1] - vi[0], Wj[2] - vi[1], Wj[3] - vi[2]};
-  const float Ekinngbj = 0.5f * pj->conserved.mass *
-                         (Wjminvi[0] * Wjminvi[0] + Wjminvi[1] * Wjminvi[1] +
-                          Wjminvi[2] * Wjminvi[2]);
+  const float Wjminvi[3] = {Wj[1] - Wi[1], Wj[2] - Wi[2], Wj[3] - Wi[3]};
+  const float Ekinngbj = Wjminvi[0] * Wjminvi[0] + Wjminvi[1] * Wjminvi[1] +
+                         Wjminvi[2] * Wjminvi[2];
   pi->force.Ekinmax = max(pi->force.Ekinmax, Ekinngbj);
   if (mode == 1) {
-    const float Wiminvj[3] = {Wi[1] - vj[0], Wi[2] - vj[1], Wi[3] - vj[2]};
-    const float Ekinngbi = 0.5f * pi->conserved.mass *
-                           (Wiminvj[0] * Wiminvj[0] + Wiminvj[1] * Wiminvj[1] +
-                            Wiminvj[2] * Wiminvj[2]);
-    pj->force.Ekinmax = max(pj->force.Ekinmax, Ekinngbi);
+    pj->force.Ekinmax = max(pj->force.Ekinmax, Ekinngbj);
   }
 
   /* Velocity on the axis linking the particles */

src/hydro/GizmoMFM/hydro_parameters.h

@@ -53,10 +53,10 @@
 #define const_viscosity_beta 3.0f
 
 /* Prefactor for the kinetic energy condition for the entropy switch. */
-#define const_entropy_switch_ekin_fac 0.0001f
+#define const_entropy_switch_ekin_fac 0.000001f
 
 /* Prefactor for the gravitational energy condition for the entropy switch. */
-#define const_entropy_switch_grav_fac 0.0001f
+#define const_entropy_switch_grav_fac 0.000001f
 
 /*! Activate this to write a diagnostic flag variable to the snapshots. */
 #define GIZMO_FLAG_VARIABLE