curl --request POST \
  --url https://api.iotools.cloud/v1/tool/reynolds-number-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "inputMode": "velocity",
  "velocity": "2",
  "velocityUnit": "mps",
  "geometry": "circular",
  "pipeDiameter": "50",
  "lengthUnit": "mm",
  "fluid": "water20"
}
'

{
  "tool": "reynolds-number-calculator",
  "tool_version": "1.0.1",
  "outputs": {
    "status": "Re = 99,621 — turbulent flow. Water, 20 °C at 2 m/s, hydraulic diameter 0.05 m. Chaotic mixing — use Colebrook/Moody for the friction factor.",
    "result": [
      {
        "property": "Reynolds number",
        "value": "99,621"
      },
      {
        "property": "Flow regime",
        "value": "Turbulent"
      },
      {
        "property": "Velocity",
        "value": "2 m/s"
      },
      {
        "property": "Hydraulic diameter",
        "value": "0.05 m"
      },
      {
        "property": "Density",
        "value": "998.2 kg/m³"
      },
      {
        "property": "Dynamic viscosity",
        "value": "0.001002 Pa·s"
      },
      {
        "property": "Kinematic viscosity",
        "value": "1.004e-6 m²/s"
      },
      {
        "property": "Flow area",
        "value": "0.001963 m²"
      },
      {
        "property": "Volumetric flow",
        "value": "0.003927 m³/s (235.62 L/min)"
      },
      {
        "property": "Formula",
        "value": "Re = ρVD/μ = 998.2 × 2 × 0.05 / 0.001002"
      }
    ],
    "regimeTable": [
      {
        "regime": "Laminar",
        "reynolds-range": "Re < 2300",
        "behaviour": "Smooth, orderly layers — friction factor f = 64/Re.",
        "this-flow": ""
      },
      {
        "regime": "Transitional",
        "reynolds-range": "2300 – 4000",
        "behaviour": "Unstable — may switch between laminar and turbulent. Avoid designing here.",
        "this-flow": ""
      },
      {
        "regime": "Turbulent",
        "reynolds-range": "Re > 4000",
        "behaviour": "Chaotic mixing — use Colebrook/Moody for the friction factor.",
        "this-flow": "◄ This flow"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}