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VCE Overpressure (Baker-Strehlow-Tang)

Process safety · Vapor cloud explosion blast · BST 2005 / CCPS

VCE Overpressure — Baker-Strehlow-Tang
Combustion-energy scaling and Sachs-scaled distance (exact), then peak side-on overpressure from a flame-speed (Mach) blast curve, with structural/physiological damage thresholds.
⚠ Safety-critical — screening; overpressure is a curve approximation. Energy scaling & damage thresholds are exact, but the dimensionless overpressure is read from a digitized-curve approximation of the BST charts and is order-of-magnitude only. Results are dominated by the flame-speed Mach number (congestion/confinement). For design use the published BST charts or Phast / FLACS with SME review — not for safety case submission or regulatory filing.

Cloud & Geometry

kg
m
MJ/kg

Flame Speed & Yield

Mf ≈ 0.35 low/moderate congestion (NG); ≥1.0 high congestion/confinement; 5.2 ≈ detonation.

Engineering Basis

  • E = yield·M·Hc (exact); characteristic length = (E/P₀)1/3; R̄ = R / that.
  • P from a digitized BST flame-speed blast curve (log-log interpolation) — approximate.
  • Ps = P·P₀ → kPa, psi.
  • Damage: 0.3 / 1.0 / 2.3 / 3.0 / 5.0 / 15 psi (window / housing / eardrum / building / collapse / lung).
  • Standards: Baker-Strehlow-Tang 2005, CCPS VCE Guidelines 2nd Ed, TNO Multi-Energy (comparison).