Skip to main content

flow

PyPI version Python License: MIT CI DOI

GPU-accelerated incompressible Navier–Stokes solver for flow in complex geometry, built around a staggered MAC grid, a signed-distance-field (SDF) description of the solid, a cut-cell Immersed Boundary Method, and a pressure-projection step with a geometric multigrid Poisson solve. The code is written in Kokkos C++ (one source runs on the CUDA, HIP/AMD, and OpenMP backends, selected at build time) and exposed to Python through nanobind (zero-copy, on core's View↔ndarray bridge); simulations are driven from Python.

The repository is also known as pnm_from_sdf (its GitLab origin) — it computes pore-network–scale flow directly from segmented SDF geometry. The pore-network extraction itself (the former peclet.flow.pnm module) now lives in its own suite project, peclet-pnm (peclet.pnm).

Modules

Module Role
flow The CFD solver — a distributed (MPI-optional) GPU cut-cell IBM Navier–Stokes solver in physical units, built on the shared core block-decomposition + async halo layer. One code / one API / MPI-optional, with native domain boundary conditions. Exposes peclet.flow.Solver (staggered MAC, default) and peclet.flow.SolverColocated (collocated/cell-centered velocities, ABC approximate projection) — identical API via a GridLayout policy. Validated against analytics and Zick & Homsy sphere-array drag (scripts/validate_zick_homsy_sdflow.py).

The original CUDA implementation has been retired (Kokkos became canonical, 2026-06); flow was validated bit-identical to the CUDA solver — to machine precision, and against Zick & Homsy sphere-array drag — before the CUDA sources were deleted (restore point: git tag pre-cuda-retirement). The shared cut-cell IBM primitives now live in src/cut_cell_ibm.hpp; the operator headers are src/mac_*.hpp + src/flow_ibm.hpp.

Capabilities

  • Geometry: SDF solids (negative inside); the cut-cell IBM applies a Robust-Scaled no-slip / moving-wall condition and a matching cut-cell pressure operator (face openness from the SDF).
  • Native domain boundary conditions (flow): per-face periodic / no-slip wall / Dirichlet velocity (inflow) / outflow, plus per-position inlet velocity profiles. Validated on the lid-driven cavity (Ghia et al.), the developing plane channel (Poiseuille), and the backward-facing step (Armaly/Gartling).
  • Pressure multigrid: rediscretized geometric V-cycle, grid-independent, with MG-PCG and Chebyshev outer accelerators. Works on periodic, IBM, and non-periodic (BC) domains, including semi-coarsening for thin (quasi-2D) grids.
  • Time integration: pressure projection with optional incremental pressure, explicit (Koren) or implicit-deferred-correction advection, and Picard outer iteration.

Build

# Canonical: build + install via scikit-build-core
CMAKE_PREFIX_PATH="$PWD/../extern/install/<backend>" pip install .   # -> peclet.flow
# Or a dev cmake build (nanobind found via the active interpreter, no cmakedir needed):
cmake -S . -B build -DCMAKE_PREFIX_PATH="$PWD/../extern/install/<backend>" && cmake --build build -j
# distributed flow build (opt-in MPI):
cmake -S . -B build_mpi -DCFD_BUILD_MPI=ON -DCMAKE_PREFIX_PATH="$PWD/../extern/install/<backend>" \
  && cmake --build build_mpi -j

<backend> is one of nvidia-cuda / host-openmp / lumi-hip under ../extern/install/, produced once by ../tools/bootstrap_deps.sh (a hard build dependency). Requirements: a Kokkos backend (CUDA/HIP/OpenMP — CUDA is just one option, not required), a C++20 host compiler, nanobind + scikit-build-core, and — for distributed flow — MPI. Python dependencies live in a virtual environment (.venv).

Run / verify

Simulations are scripts, not C++ mains. The scripts/verify_*_sdflow.py files are the canonical verification entry points:

source .venv/bin/activate
python scripts/verify_lid_cavity_sdflow.py     # lid-driven cavity vs Ghia, Ghia & Shin (1982)
python scripts/verify_channel_sdflow.py        # developing plane channel -> Poiseuille
python scripts/verify_bfs_sdflow.py            # backward-facing step (reattachment length)
ctest --test-dir build_mpi --output-on-failure # the multi-rank C++ test suite

Documentation

API documentation (C++ classes/kernels and Python scripts) is generated with Doxygen and published to GitHub Pages by the Documentation CI workflow. Build it locally with:

doxygen docs/Doxyfile      # output in docs/html/index.html

The architecture, conventions, and design rationale are described in CLAUDE.md and the design notes under doc/ in the repository.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distributions

No source distribution files available for this release.See tutorial on generating distribution archives.

Built Distributions

If you're not sure about the file name format, learn more about wheel file names.

peclet_flow_cu13-0.4.0-cp313-cp313-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl (1.6 MB view details)

Uploaded CPython 3.13manylinux: glibc 2.27+ x86-64manylinux: glibc 2.28+ x86-64

peclet_flow_cu13-0.4.0-cp312-cp312-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl (1.6 MB view details)

Uploaded CPython 3.12manylinux: glibc 2.27+ x86-64manylinux: glibc 2.28+ x86-64

peclet_flow_cu13-0.4.0-cp311-cp311-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl (1.6 MB view details)

Uploaded CPython 3.11manylinux: glibc 2.27+ x86-64manylinux: glibc 2.28+ x86-64

peclet_flow_cu13-0.4.0-cp310-cp310-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl (1.6 MB view details)

Uploaded CPython 3.10manylinux: glibc 2.27+ x86-64manylinux: glibc 2.28+ x86-64

File details

Details for the file peclet_flow_cu13-0.4.0-cp313-cp313-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl.

File metadata

File hashes

Hashes for peclet_flow_cu13-0.4.0-cp313-cp313-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl
Algorithm Hash digest
SHA256 b143a925b359f7e665d5c7dc099959a3ef9148eadb7b70d99cb37205ba18dd1d
MD5 d6448b795a47b6fab31c6a0314b81ff2
BLAKE2b-256 9e03851b4d97f059b6e6eb4d559c6c6003dcc9e8832e0fcd12c34fe50b6ad897

See more details on using hashes here.

Provenance

The following attestation bundles were made for peclet_flow_cu13-0.4.0-cp313-cp313-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl:

Publisher: release.yml on computational-chemical-engineering/peclet-flow

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file peclet_flow_cu13-0.4.0-cp312-cp312-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl.

File metadata

File hashes

Hashes for peclet_flow_cu13-0.4.0-cp312-cp312-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl
Algorithm Hash digest
SHA256 fa7fe7c42cecb43c9d0e832b9fd222bc5e20129b01a846b27211c2caa6a310d9
MD5 b473a9c2025d082ba1bc398402885a76
BLAKE2b-256 73c60c500e444b79598317340e8dfd8310fc4c91518cba8c4b504c6cee35e2ca

See more details on using hashes here.

Provenance

The following attestation bundles were made for peclet_flow_cu13-0.4.0-cp312-cp312-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl:

Publisher: release.yml on computational-chemical-engineering/peclet-flow

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file peclet_flow_cu13-0.4.0-cp311-cp311-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl.

File metadata

File hashes

Hashes for peclet_flow_cu13-0.4.0-cp311-cp311-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl
Algorithm Hash digest
SHA256 38951fb62431aa5655d7904187fb51169b56c5919a8f0e3a33c002a7b927a5c0
MD5 e1ba5c34a27f5d26e897fb59ea9b0070
BLAKE2b-256 f7f4a62ff8aa6e059982203e28486689e2b99eaa005d8b00295a785c5cb3418f

See more details on using hashes here.

Provenance

The following attestation bundles were made for peclet_flow_cu13-0.4.0-cp311-cp311-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl:

Publisher: release.yml on computational-chemical-engineering/peclet-flow

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file peclet_flow_cu13-0.4.0-cp310-cp310-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl.

File metadata

File hashes

Hashes for peclet_flow_cu13-0.4.0-cp310-cp310-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl
Algorithm Hash digest
SHA256 a9c70eca16d94d73f922ce675294168c32cda10e7e26b2567fb9b504d5e15d76
MD5 c1bd08219f43a7aae6a34aa9da23d055
BLAKE2b-256 42eadf801c666602a782654cdc64c8015a5ad54b795d54d05f26c79477bf8d2b

See more details on using hashes here.

Provenance

The following attestation bundles were made for peclet_flow_cu13-0.4.0-cp310-cp310-manylinux_2_27_x86_64.manylinux_2_28_x86_64.whl:

Publisher: release.yml on computational-chemical-engineering/peclet-flow

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

This release

0.4.0 This release

4 files

0.3.0

4 files

0.2.0

4 files

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Depot Continuous Integration Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page