vonkarman-core 0.2.0

Core types and traits for the vonkarman Navier-Stokes solver
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81

use crate::field::{GridSpec, VectorField};
use crate::float::Float;
use ndarray::Array3;
use num_complex::Complex;
use serde::{Deserialize, Serialize};

/// Which domain topology the solver uses.
#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
pub enum DomainType {
    Periodic3D,
    Axisymmetric,
}

/// Physical parameters for the simulation.
#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
pub struct PhysicsParams {
    /// Kinematic viscosity.
    pub nu: f64,
    /// Reynolds number (redundant with nu, but convenient).
    pub re: f64,
    /// Domain type.
    pub domain: DomainType,
}

/// Full-state snapshot for I/O and diagnostics.
pub struct Snapshot<F: Float> {
    pub time: F,
    pub step: u64,
    pub dt: F,
    pub velocity: VectorField<F>,
    pub vorticity: VectorField<F>,
    /// Spectral velocity coefficients (for exact restart).
    pub u_hat: [Array3<Complex<F>>; 3],
    pub grid: GridSpec,
    pub params: PhysicsParams,
}

/// Solver interface. Implemented by Periodic3D and Axisymmetric.
pub trait Domain<F: Float> {
    /// Advance one timestep.
    fn step(&mut self);

    /// Current simulation time.
    fn time(&self) -> F;

    /// Current step count.
    fn step_count(&self) -> u64;

    /// Current timestep size.
    fn dt(&self) -> F;

    /// Total kinetic energy: (1/2) * integral |u|^2 dx.
    fn energy(&self) -> F;

    /// Enstrophy: integral |omega|^2 dx.
    fn enstrophy(&self) -> F;

    /// Helicity: integral u . omega dx.
    fn helicity(&self) -> F;

    /// Superhelicity: integral omega . curl(omega) dx.
    fn superhelicity(&self) -> F;

    /// Max vorticity magnitude: ||omega||_inf.
    fn max_vorticity(&self) -> F;

    /// CFL-based adaptive timestep.
    fn cfl_dt(&self) -> F;

    /// Borrow the spectral velocity state.
    fn u_hat(&self) -> &[Array3<Complex<F>>; 3];

    /// Grid specification.
    fn grid(&self) -> &GridSpec;

    /// Physics parameters.
    fn params(&self) -> &PhysicsParams;

    /// Full-state snapshot for I/O.
    fn snapshot(&self) -> Snapshot<F>;
}