Fixed on/off switch for forcing and accretion, now forcing only happens for first 1000 steps (currently hard-coded), and accretion only happen after 1000 steps.

acc/mhd_solver/stencil_defines.h

@@ -82,6 +82,7 @@
 	FUNC(AC_M_sink_Msun),\
         FUNC(AC_soft),\
         FUNC(AC_accretion_range),\
+        FUNC(AC_switch_accretion),\
         /* Run params */\
         FUNC(AC_cdt), \
         FUNC(AC_cdtv), \

acc/mhd_solver/stencil_process.sps

@@ -68,7 +68,6 @@ sink_gravity(int3 globalVertexIdx){
 #endif
 
 
-
 #if LSINK
 // Give Truelove density
 Scalar
@@ -93,9 +92,11 @@ sink_accretion(int3 globalVertexIdx, in ScalarField lnrho, Scalar dt){
                                      DCONST_REAL(AC_sink_pos_z)};
     const Scalar profile_range = DCONST_REAL(AC_accretion_range);
     const Scalar accretion_distance = length(grid_pos - sink_pos);
+    int accretion_switch = DCONST_INT(AC_switch_accretion); 
     Scalar accretion_density; 
-     
     Scalar weight;
+
+    if (accretion_switch == 1){   
 //    const Scalar weight = exp(-(accretion_distance/profile_range));   
         // Step function weighting 
         if ((accretion_distance) <= profile_range){
@@ -117,9 +118,13 @@ sink_accretion(int3 globalVertexIdx, in ScalarField lnrho, Scalar dt){
             rate = Scalar(0.0);
         }
         accretion_density = weight * rate ;
+    } else {
+        accretion_density = 0; 
+    }
     return accretion_density;
 } 
 
+
 Vector
 sink_accretion_velocity(int3 globalVertexIdx, in VectorField uu, Scalar dt) {
     const Vector grid_pos = (Vector){(globalVertexIdx.x - nx_min) * dsx,
@@ -130,9 +135,10 @@ sink_accretion_velocity(int3 globalVertexIdx, in VectorField uu, Scalar dt) {
                                      DCONST_REAL(AC_sink_pos_z)};
     const Scalar profile_range = DCONST_REAL(AC_accretion_range);
     const Scalar accretion_distance = length(grid_pos - sink_pos);   
-
+    int accretion_switch = DCONST_INT(AC_switch_accretion); 
     Vector accretion_velocity; 
 
+    if (accretion_switch == 1){
         Scalar weight;
         // Step function weighting 
         if ((accretion_distance) <= profile_range){
@@ -148,6 +154,9 @@ sink_accretion_velocity(int3 globalVertexIdx, in VectorField uu, Scalar dt) {
             rate = (Vector){0.0, 0.0, 0.0};
         }
         accretion_velocity = weight * rate ;
+    } else {
+        accretion_velocity = (Vector){0.0, 0.0, 0.0};
+    }
     return accretion_velocity;
 }
 #endif
@@ -326,22 +335,35 @@ heat_transfer(in VectorField uu, in ScalarField lnrho, in ScalarField tt)
 
 #if LFORCING
 Vector
-simple_vortex_forcing(Vector a, Vector b, Scalar magnitude)
-{
+    simple_vortex_forcing(Vector a, Vector b, Scalar magnitude){
+    int accretion_switch = DCONST_INT(AC_switch_accretion); 
+    
+    if (accretion_switch == 0){
         return magnitude * cross(normalized(b - a), (Vector){ 0, 0, 1}); // Vortex
+    } else { 
+        return (Vector){0,0,0};  
+    }
+}        
+Vector
+    simple_outward_flow_forcing(Vector a, Vector b, Scalar magnitude){
+    int accretion_switch = DCONST_INT(AC_switch_accretion);
+    if (accretion_switch == 0){            
+        return magnitude * (1 / length(b - a)) * normalized(b - a); // Outward flow
+    } else {
+        return (Vector){0,0,0};
+    }
 }
 
-Vector
-simple_outward_flow_forcing(Vector a, Vector b, Scalar magnitude)
-{
-    return magnitude * (1 / length(b - a)) * normalized(b - a); // Outward flow
-}
 
 
 // The Pencil Code forcing_hel_noshear(), manual Eq. 222, inspired forcing function with adjustable helicity
 Vector
 helical_forcing(Scalar magnitude, Vector k_force, Vector xx, Vector ff_re, Vector ff_im, Scalar phi)
 {
+    int accretion_switch = DCONST_INT(AC_switch_accretion);
+    if (accretion_switch == 0){
+
+    
         // JP: This looks wrong:
         //    1) Should it be dsx * nx instead of dsx * ny?
         //    2) Should you also use globalGrid.n instead of the local n?
@@ -371,12 +393,19 @@ helical_forcing(Scalar magnitude, Vector k_force, Vector xx, Vector ff_re, Vecto
                                  ff_re.y*real_comp_phase - ff_im.y*imag_comp_phase,
                                  ff_re.z*real_comp_phase - ff_im.z*imag_comp_phase};
     
+    
         return force;
+    } else {
+        return (Vector){0,0,0}; 
+    }
 }
 
 Vector
 forcing(int3 globalVertexIdx, Scalar dt)
 {
+    int accretion_switch = DCONST_INT(AC_switch_accretion);
+    if (accretion_switch == 0){
+
         Vector a = Scalar(.5) * (Vector){globalGridN.x * dsx,
                                          globalGridN.y * dsy,
                                          globalGridN.z * dsz}; // source (origin)
@@ -408,6 +437,9 @@ forcing(int3 globalVertexIdx, Scalar dt)
     
         if (is_valid(force)) { return force; }
         else                 { return (Vector){0, 0, 0}; }
+    } else {
+          return (Vector){0,0,0};
+    }
 }
 #endif // LFORCING
 

src/standalone/simulation.cc

@@ -252,11 +252,11 @@ run_simulation(void)
 #if LSINK
 
         const AcReal sum_mass = acReduceScal(RTYPE_MAX, VTXBUF_ACCRETION);
-	if (i > 1000) {
+//	if (i > 1000) {
             accreted_mass = accreted_mass + sum_mass;
-        } else {
-            accreted_mass = 0.0;
-        }
+//        } else {
+//            accreted_mass = 0.0;
+//        }
         AcReal sink_mass = 0.0;
         //if (i > 1000 ) {
 	    sink_mass = mesh_info.real_params[AC_M_sink_init] + accreted_mass;
@@ -265,14 +265,19 @@ run_simulation(void)
         printf("accreted mass is: %e \n", accreted_mass); 
         acLoadDeviceConstant(AC_M_sink, sink_mass);
         vertex_buffer_set(VTXBUF_ACCRETION, 0.0, mesh);
+        
+        int on_off_switch;
+        if (i < 1000) {
+            on_off_switch = 0; //accretion is off till 1000 steps.
+        } else {
+            on_off_switch = 1;
+        }
+        acLoadDeviceConstant(AC_switch_accretion, on_off_switch);
 #endif
 
 #if LFORCING
         const ForcingParams forcing_params = generateForcingParams(mesh_info);
-        if (i > 1000) {
         loadForcingParamsToDevice(forcing_params);
-        } 
-            
 #endif