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comparison src/SbpOperators/volumeops/derivatives/dissipation.jl @ 1355:102ebdaf7c11 feature/variable_derivatives

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Merge default
author Jonatan Werpers <jonatan@werpers.com>
date Wed, 08 Feb 2023 21:21:28 +0100
parents d60a10ad6579
children 356ec6a72974
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1210:fa0800591306 1355:102ebdaf7c11
1 function undivided_dissipation(g::EquidistantGrid, p, direction) 1 """
2 undivided_skewed04(g::EquidistantGrid, p, direction)
3
4 Create undivided difference operators approximating the `p`th derivative. The
5 operators do not satisfy any SBP-property and are meant to be used for
6 building artificial dissipation terms.
7
8 The operators and how they are used to create accurate artifical dissipation
9 is described in "K. Mattsson, M. Svärd, and J. Nordström, “Stable and Accurate
10 Artificial Dissipation,” Journal of Scientific Computing, vol. 21, no. 1, pp.
11 57–79, Aug. 2004"
12 """
13 function undivided_skewed04(g::EquidistantGrid, p, direction)
2 T = eltype(g) 14 T = eltype(g)
3 interior_weights = T.(dissipation_interior_weights(p)) 15 interior_weights = T.(dissipation_interior_weights(p))
4 16
5 D = stencil_operator_distinct_closures( 17 D = stencil_operator_distinct_closures(
6 g, 18 g,
18 ) 30 )
19 31
20 return D, Dᵀ 32 return D, Dᵀ
21 end 33 end
22 34
23 undivided_dissipation(g::EquidistantGrid{1}, p) = undivided_dissipation(g, p, 1) 35 undivided_skewed04(g::EquidistantGrid{1}, p) = undivided_skewed04(g, p, 1)
24 36
25 function dissipation_interior_weights(p) 37 function dissipation_interior_weights(p)
26 if p == 0 38 if p == 0
27 return (1,) 39 return (1,)
28 end 40 end
45 end 57 end
46 58
47 dissipation_lower_closure_size(weights) = midpoint(weights) - 1 59 dissipation_lower_closure_size(weights) = midpoint(weights) - 1
48 dissipation_upper_closure_size(weights) = length(weights) - midpoint(weights) 60 dissipation_upper_closure_size(weights) = length(weights) - midpoint(weights)
49 61
50 dissipation_lower_closure_stencils(interior_weights) = ntuple(i->Stencil(interior_weights..., center=i ), dissipation_lower_closure_size(interior_weights)) 62 function dissipation_lower_closure_stencils(interior_weights)
51 dissipation_upper_closure_stencils(interior_weights) = ntuple(i->Stencil(interior_weights..., center=length(interior_weights)-dissipation_upper_closure_size(interior_weights)+i), dissipation_upper_closure_size(interior_weights)) 63 stencil(i) = Stencil(interior_weights..., center=i)
64 return ntuple(i->stencil(i), dissipation_lower_closure_size(interior_weights))
65 end
66
67 function dissipation_upper_closure_stencils(interior_weights)
68 center(i) = length(interior_weights) - dissipation_upper_closure_size(interior_weights) + i
69 stencil(i) = Stencil(interior_weights..., center=center(i))
70 return ntuple(i->stencil(i), dissipation_upper_closure_size(interior_weights))
71 end
52 72
53 function dissipation_transpose_lower_closure_stencils(interior_weights) 73 function dissipation_transpose_lower_closure_stencils(interior_weights)
54 closure = ntuple(i->dissipation_transpose_lower_closure_stencil(interior_weights, i), length(interior_weights)) 74 closure = ntuple(i->dissipation_transpose_lower_closure_stencil(interior_weights, i), length(interior_weights))
55 75
56 N = maximum(s->length(s.weights), closure) 76 N = maximum(s->length(s.weights), closure)