Process & Geometry
kPa
mm
—
kg/m³
Choked Flow Indicator
Pressure Ratio ΔP / P₁--
SubsonicCritical (0.47)Choked
Awaiting Input
Flow Measurement
Volumetric Flow (Qv)
--m³/h
Mass Flow (ṁ)
--kg/s
Reynolds Number (Red)
--—
Pressure Recovery
--% of ΔP
Choked Flow Status
--
ISO 5167 Equations
Qv = Cd · Ao · √(2·ΔP / ρ)
Ao = π·d²/4 (m²), ΔP in Pa, ρ in kg/m³
ṁ = Qv · ρ
Red = 4·ṁ / (π·d·μ) – assuming μ ≈ 0.001 Pa·s for water
Pressure recovery: approx. 65–85% ΔP for orifice plates.
Choked flow for gas when ΔP/P₁ ≥ 0.53 (ideal gas, γ=1.4).
Orifice Cross‑Section (Pressure Zones)
Flow Rate vs ΔP Curve