Implement regularizations for Euler eq

Implements the Navier-Stokes and general regularization from J.-L. Guermond and B. Popov, “Viscous regularization of the euler equations and entropy principles,” SIAM Journal on Applied Mathematics, vol. 74, no. 2, pp. 284–305, 2014.

src/TCI/entropyproduction.jl

@@ -36,7 +36,18 @@ function compute_indicator!(
   # entropy residual
   dt = t - tm1
   dt <= 0 && return # occurs on first time step when no previous entropy is available
-  EP .= abs.((E - Em1) / dt + 0.5  * D * (F + Fm1) .* invjac)
+
+  # use inplace operations
+  @. Fm1 -= F
+  mul!(EP, D, Fm1, -1.0, false)
+  @. EP .*= invjac
+  @. EP += (E - Em1) / dt
+  @. EP = abs(EP)
+
+  # @. EP = (E - Em1) / dt
+  # Fm1 .-= F
+  # mul!(EP, D, Fm1, -1.0, 1.0)
+  # EP .= abs.((E - Em1) / dt + 0.5  * D * (F + Fm1) .* invjac)
 
   # entropy jumps
   for k = 1:K