Merge branch 'HLL_Davis_Polytropic_Euler' of github.com:DanielDoehrin…

…g/Trixi.jl into HLL_Davis_Polytropic_Euler

src/equations/polytropic_euler_2d.jl

@@ -198,21 +198,6 @@ For details see Section 3.2 of the following reference
     return SVector(f1, f2, f3)
 end
 
-"""
-    flux_winters_etal(u_ll, u_rr, orientation,
-                      equations::PolytropicEulerEquations2D)
-
-Entropy conserving two-point flux for isothermal or polytropic gases.
-Requires a special weighted Stolarsky mean for the evaluation of the density
-denoted here as `stolarsky_mean`. Note, for isothermal gases where `gamma = 1`
-this `stolarsky_mean` becomes the [`ln_mean`](@ref).
-
-For details see Section 3.2 of the following reference
-- Andrew R. Winters, Christof Czernik, Moritz B. Schily & Gregor J. Gassner (2020)
-  Entropy stable numerical approximations for the isothermal and polytropic
-  Euler equations
-  [DOI: 10.1007/s10543-019-00789-w](https://doi.org/10.1007/s10543-019-00789-w)
-"""
 @inline function flux_winters_etal(u_ll, u_rr, orientation::Integer,
                                    equations::PolytropicEulerEquations2D)
     # Unpack left and right state