Basic Usage

Read A Dataset

flow_props expects a dataset that has already been read by cfd-io.

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import cfd_io

dataset = cfd_io.read_file("solution.vtu")

For split solution/grid formats, provide the separate grid file through cfd-io.

Extract Profiles

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from flow_props import extract_profiles

profiles = extract_profiles(dataset, stations=[10, 50, 100])
print(profiles[0].keys())

Each extracted profile includes:

• x, y
• eta
• one array per flow field available in the input dataset

For config-driven extraction, flow-props init --bl creates bl.toml. Set fname to a structured HDF5 file, then run flow-props run --bl. With profiles_output configured, the extracted wall-normal profiles are written as multi-zone Tecplot ASCII alongside the BL property table. cfd-io handles file reading; flow-props does not convert CFD formats. Leave [stations] empty to process all i-indices from 0 through Nx - 1 with step 1, or choose one station-selection mode to limit the run.

Only the htot_derivative criterion requires gas constants. The tool reads gamma and r_gas from HDF5 attributes, fills missing values from an adjacent flow_conditions.json, and allows optional [gas] overrides. The default velocity_ratio criterion does not require those values.

Compute Boundary-Layer Properties

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from flow_props import run_bl

bl_results = run_bl(
    dataset,
    stations=[10, 50, 100],
    criterion="velocity_ratio",
    threshold=0.99,
)

Available edge criteria currently include:

• velocity_ratio
• enthalpy_ratio
• velocity_gradient

Compute Entropy-Layer Thickness

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from flow_props import run_entropy

entropy_results = run_entropy(
    dataset,
    stations=[10, 50, 100],
    threshold=0.25,
)

Compute Wall Quantities

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from flow_props import run_wall

wall_results = run_wall(
    dataset,
    mu_wall=1.8e-5,
    rho_inf=0.12,
    u_inf=2500.0,
    k_wall=0.03,
    cp=1005.0,
    T_wall=300.0,
    T_inf=220.0,
)

Typical Workflow

In practice, a common pattern is:

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import cfd_io
from flow_props import run_bl, run_entropy, run_wall

dataset = cfd_io.read_file("solution.vtu")

bl_results = run_bl(dataset, stations=[20, 40, 60])
entropy_results = run_entropy(dataset, stations=[20, 40, 60])
wall_results = run_wall(dataset, mu_wall=1.8e-5)

That gives you station-wise layer quantities plus surface distributions from the same CFD input.