Small fixes to callbacks

src/callbacks/density_reinit.jl

@@ -6,8 +6,10 @@ Callback to reinitialize the density field when using [`ContinuityDensity`](@ref
 # Keywords
 - `interval=0`:              Reinitialize the density every `interval` time steps.
 - `dt`:                      Reinitialize the density in regular intervals of `dt` in terms
-                             of integration time.
-- `reinit_initial_solution`: Reinitialize the initial solution (default=false)
+                             of integration time. This callback does not add extra time
+                             steps / `tstops`; instead, reinitialization is triggered at
+                             the first solver step after each `dt` interval has elapsed.
+- `reinit_initial_solution`: Reinitialize the initial solution (default=true)
 """
 mutable struct DensityReinitializationCallback{I}
     interval::I
@@ -102,4 +104,6 @@ function (reinit_callback::DensityReinitializationCallback)(integrator)
     @trixi_timeit timer() "reinit density" reinit_density!(vu_ode, semi)
 
     reinit_callback.last_t = integrator.t
+
+    u_modified!(integrator, true)
 end

src/general/initial_condition.jl

@@ -368,8 +368,8 @@ function InitialCondition(sol::ODESolution, system, semi; use_final_velocity=fal
 
     v_ode, u_ode = sol.u[end].x
 
+    v = wrap_v(v_ode, system, semi)
     u = wrap_u(u_ode, system, semi)
-    v = wrap_u(v_ode, system, semi)
 
     # Check if particles come too close especially when the surface exhibits large curvature
     too_close = find_too_close_particles(u, min_particle_distance)

src/schemes/fluid/weakly_compressible_sph/system.jl

@@ -390,6 +390,13 @@ end
 
 function reinit_density!(system::WeaklyCompressibleSPHSystem, v, u,
                          v_ode, u_ode, semi)
+    (; density_calculator) = system
+
+    reinit_density!(system, density_calculator, v, u, v_ode, u_ode, semi)
+end
+
+function reinit_density!(system::WeaklyCompressibleSPHSystem, ::ContinuityDensity, v, u,
+                         v_ode, u_ode, semi)
     # Compute density with `SummationDensity` and store the result in `v`,
     # overwriting the previous integrated density.
     summation_density!(system, semi, u, u_ode, v[end, :])
@@ -405,6 +412,11 @@ function reinit_density!(system::WeaklyCompressibleSPHSystem, v, u,
     return system
 end
 
+function reinit_density!(system::WeaklyCompressibleSPHSystem, ::SummationDensity, v, u,
+                         v_ode, u_ode, semi)
+    return system
+end
+
 function reinit_density!(system, v, u, v_ode, u_ode, semi)
     return system
 end