Stokes settling velocity API

Computes the terminal settling velocity of a small sphere in a viscous fluid by Stokes' law v = (ρp−ρf)·g·d²/(18·μ), returning the velocity, particle Reynolds number, and a validity flag (Stokes valid for Re < ~1). Answers 'How fast does a particle settle in water?', 'Is Stokes law valid for this particle size?'.

Price$0.06per request

MethodPOST

Route/v1/engineering/stokes-settling

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

engineeringthermofluidsfluidsstokessettling-velocitysedimentationparticleterminal-velocityclarifier

API URLhttps://x402.hexl.dev/v1/engineering/stokes-settling

Integration docs

Example request

{
  "particleDiameterM": 0.0001,
  "particleDensityKgM3": 2650,
  "fluidDensityKgM3": 998,
  "dynamicViscosityPaS": 0.001
}

Example response

{
  "particleDiameterM": 0.0001,
  "particleDensityKgM3": 2650,
  "fluidDensityKgM3": 998,
  "dynamicViscosityPaS": 0.001,
  "settlingVelocityMs": 0.009000325,
  "settlingVelocityMmS": 9.000325,
  "particleReynoldsNumber": 0.898232,
  "stokesRegimeValid": true,
  "formula": "v = (ρp - ρf)*g*d² / (18*μ)",
  "interpretation": "Particle Reynolds < 1: Stokes' law applies."
}

Input schema

{
  "type": "object",
  "required": [
    "particleDiameterM",
    "particleDensityKgM3",
    "fluidDensityKgM3",
    "dynamicViscosityPaS"
  ],
  "properties": {
    "particleDiameterM": {
      "type": "number",
      "description": "particle diameter (m)",
      "examples": [
        0.0001
      ]
    },
    "particleDensityKgM3": {
      "type": "number",
      "description": "particle density (kg/m^3)"
    },
    "fluidDensityKgM3": {
      "type": "number",
      "description": "fluid density (kg/m^3)"
    },
    "dynamicViscosityPaS": {
      "type": "number",
      "description": "fluid dynamic viscosity μ (Pa·s)",
      "examples": [
        0.001
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}