Theory 39/Strouhal Number/Heat exchanger tubes
Tube Vibration Locks at a Strouhal
The claim
Flow-induced vibration of heat exchanger tubes becomes severe when the shedding Strouhal number matches the tube's natural frequency, so failures cluster at particular velocities.
01Mechanism
Vortex shedding exerts a periodic force; when its frequency coincides with a structural mode, resonance amplifies the response.
02Prediction
Failures should cluster at velocities matching the Strouhal condition.
03Refutation
Failures tracking velocity alone would remove the resonance.