Chapter 1 — CFDrs Architecture and Problem Setup

Figure 1.1 — CFDrs Architecture and Problem Setup

CFDrs is a workspace of CFD-focused crates organized so that physics, geometry, and solver concerns live in distinct crates and compose through workspace-level contracts. This Part introduces the architecture and points at the example scenarios that exercise every contract.

Crate Map

Every solver crate depends on cfd-core and cfd-math; geometry crates (cfd-schematics) are depended on by cfd-{1,2,3}d. The cross-cutting contracts — boundary conditions, time-stepping, state vectors — live in cfd-core and are referenced by example chapters throughout this book.

Boundary Conditions

cfd-core owns the generic BoundaryCondition<T> enum and the named BoundaryConditionSet<T> collection. Solver crates consume these contracts through their grid- or mesh-specific setup paths.

use cfd_core::physics::boundary::{BoundaryCondition, BoundaryConditionSet};
use leto::geometry::Vector3;

let mut boundaries = BoundaryConditionSet::<f64>::new();
boundaries
    .add(
        "inlet",
        BoundaryCondition::velocity_inlet(Vector3::new(1.0, 0.0, 0.0)),
    )
    .add("walls", BoundaryCondition::wall_no_slip())
    .add("outlet", BoundaryCondition::pressure_outlet(0.0));

The CFDrs Simulation Lifecycle

+------------+   +-----------+   +----------+   +----------+
| Geometry   |-->| Mesh/Grid |-->| Boundary |-->| Initial  |
| (CSG)      |   |           |   | wiring   |   | state    |
+------------+   +-----------+   +----------+   +----------+
                                                    |
                                                    v
+------------+   +-----------+   +----------+
| Posterior  |<--| Solve     |<--| Time     |
| analysis   |   | (linear   |   | step     |
|            |   |  iter.)   |   |          |
+------------+   +-----------+   +----------+

• Geometry → Mesh is handled in cfd-schematics (CSG) and cfd-{2,3}d/grid.rs.
• Boundary contracts live in [cfd_core::physics::boundary].
• Time stepping is configurable per solver (cfd-2d::time / cfd-3d::time / adaptive in cfd-2d::adaptive).
• Posterior means DVH-equivalent (cavitation risk, shear envelope, Reynolds stress), reported in user-supplied hooks.

Atlas Stack Interface

CFDrs is mid-migration to the Atlas stack. Where a crate already declares Atlas crates in Cargo.toml, the migration is considered complete; where ndarray or nalgebra is still in the manifest, the crate is in bulk-migration phase. See Atlas Dependency Map for the per-crate table.

Examples Referenced by This Chapter

• cfd_demo — minimum end-to-end setup.
• enhanced_cfd_demo — diagnostics enabled.
• adaptive_time_stepping_demo — demonstrates the time-stepping hook with adaptive CFL.

Further Reading

• cfd-core source
• cfd-2d source
• Atlas Dependency Map