Added abstract vector for max_abs_speed_naive and CompressibleEulerMulticomponentEquations2D.

[SimonCan]

To run on meshes, like p4est meshes we needed a max_abs_speed_naive function for general vectors/directions.

[github-actions]

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• The code can be understood easily.
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Created with ❤️ by the Trixi.jl community.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.81%. Comparing base (1d75f8f) to head (1a1d7bc).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2607   +/-   ##
=======================================
  Coverage   96.81%   96.81%           
=======================================
  Files         535      536    +1     
  Lines       42813    42859   +46     
=======================================
+ Hits        41446    41492   +46     
  Misses       1367     1367           

Flag	Coverage Δ
unittests	96.81% <100.00%> (+<0.01%)	⬆️

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[DanielDoehring]

Could you add unit tests that show that the speed for the vectors [1, 0] and [0, 1]matches the existing speed for directions 1, 2?

[SimonCan]

Still getting some type instability and memory allocations. I am stumped, as any attempted fix does nothing.

[ranocha]

Did you check this code for type instabilities? Do you get type instabilities with mainstream solvers like shock capturing Hennemann & Gassner?

[DanielDoehring]

+1 that is something you should check first

[SimonCan]

Would that not require a min_max_speed_davis? If so it might just shift the type instability.

[ranocha]

Your new code looks reasonable. Thus, I guess the type instabilities come from this choice of solver. You can also profile it or use Cthulhu.jl to @descend into our rhs!.

[SimonCan]

It seems that the type instability does not come from max_abs_speed_naive after all.

[SimonCan]

Strangely enough,
@btime Trixi.rhs!($du, $sol.u[1], $semi, 0.0)
does not give me any extra memory allocations.

[DanielDoehring]

I changed the normal stuff a bit to follow

Trixi.jl/src/equations/compressible_euler_2d.jl

Lines 1416 to 1433 in 1d75f8f

	@inline function max_abs_speed_naive(u_ll, u_rr, normal_direction::AbstractVector,
	equations::CompressibleEulerEquations2D)
	rho_ll, v1_ll, v2_ll, p_ll = cons2prim(u_ll, equations)
	rho_rr, v1_rr, v2_rr, p_rr = cons2prim(u_rr, equations)
	# Calculate normal velocities and sound speed
	# left
	v_ll = (v1_ll * normal_direction[1]
	+
	v2_ll * normal_direction[2])
	c_ll = sqrt(equations.gamma * p_ll / rho_ll)
	# right
	v_rr = (v1_rr * normal_direction[1]
	+
	v2_rr * normal_direction[2])
	c_rr = sqrt(equations.gamma * p_rr / rho_rr)
	return max(abs(v_ll), abs(v_rr)) + max(c_ll, c_rr) * norm(normal_direction)

closer. But better check this for a convergence problem or with unit tests

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	@inline function max_abs_speed_naive(u_ll::SVector{N,T}, u_rr::SVector{N,T}, normal_direction::SVector{2,T},
	equations::CompressibleEulerMulticomponentEquations2D) where {N, T<:AbstractFloat}
	@inline function max_abs_speed_naive(u_ll::SVector{N, T}, u_rr::SVector{N, T},
	normal_direction::SVector{2, T},
	equations::CompressibleEulerMulticomponentEquations2D) where {
	N,
	T <:
	AbstractFloat
	}