🌪️ von Kármán Vortex Shedding (Strouhal Frequency)

Determine cross-flow cylinder vortex shedding frequency (fs in Hz), Strouhal number (St), fluctuating lift force, and vortex street dimensions (h/a = 0.281).

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated
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⚡ Calculs faits 23
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📅 Mise en service Jun 2026
⏱️ Latence < 1 ms
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💾 Télécharger Fortran 90

🌪️ Cross-Flow Cylinder & von Kármán Vortex Street Wake

Real-time visual simulation of periodic alternating clockwise and counter-clockwise vortex core shedding

📝 Configuration & Presets

🏭 Industrial Stack (1.2m) 🌊 Subsea Pipeline (400mm) ⚡ Power Cable Aeolian Humming 🚰 Heat Exchanger Tube (20mm)
📐 Cylinder Diameter & Flow Velocity
💧 Fluid Physical Properties
Air: ~1.2 kg/m³, Water: ~1000 kg/m³
Air: ~0.0182 cP, Water: ~1.0 cP
Strouhal Vortex Formulations:
• Strouhal Number: St = (fs · D) / U ≈ 0.198 (1 − 19.7/Re)
• Shedding Frequency: fs = (St · U) / D [Hz]
• Fluctuating Lift: F′L,rms = ½ ρ U² D · CL,rms [N/m]
• Stable Spacing Ratio: h / a ≈ 0.281

📊 Vortex Shedding Results

Configure inputs and click Compute to view results.

📘 Calculation Methodology & Strouhal Standards

Strouhal Shedding Law

Above $Re_D \approx 47$, laminar boundary layer separation becomes unstable, shedding regular alternate vortex pairs into the wake with non-dimensional frequency $St$:

fs = (St · U) / D

Vortex-Induced Vibration (VIV)

Periodic pressure imbalance from alternating vortex shedding exerts fluctuating cross-flow lift forces that can cause destructive resonance in chimneys, marine risers, and tubes.

Key Engineering Assumptions

  • Uniform steady 2D cross-flow past smooth circular cylinder.
  • Subcritical turbulent boundary layer separation ($Re_D < 2\times 10^5$).
  • von Kármán stability spacing ratio $h/a \approx 0.281$.