structure
definition
def or abbrev
OneStepData
show as:
view Lean formalization →
formal statement (Lean)
45structure OneStepData where
46 nu : ℝ
47 h : ℝ
48 dt : ℝ
49 gradMax : ℝ
50 nu_pos : 0 < nu
51 h_pos : 0 < h
52 dt_pos : 0 < dt
53 gradMax_nonneg : 0 ≤ gradMax
54 advectionBound : ℝ
55 advectionBound_nonneg : 0 ≤ advectionBound
56 advectionBound_le_gradMax : advectionBound ≤ gradMax
57
58/-- The viscous contraction rate on the lattice: nu / h^2. -/
59def OneStepData.viscousRate (data : OneStepData) : ℝ :=
proof body
Definition body.
60 data.nu / data.h ^ 2
61
62theorem OneStepData.viscousRate_pos (data : OneStepData) :
63 0 < data.viscousRate := by
64 unfold viscousRate
65 exact div_pos data.nu_pos (pow_pos data.h_pos 2)
66
67/-- The sub-Kolmogorov condition: gradMax <= nu/h^2. -/
68def OneStepData.subKolmogorov (data : OneStepData) : Prop :=
69 data.gradMax ≤ data.viscousRate
70
71/-- When the sub-Kolmogorov condition holds, the advection rate is
72dominated by the viscous contraction rate. -/