Vortex Shedding
Subject
Vortex shedding occurs when a structural element is exposed to external flowing or regularly pulsating fluids that generate cyclic conditions which coincide with its natural frequency. A couple of excellent examples of what can go wrong if this issue is not properly addressed are the Tacoma narrows bridge (1940) and the London Thames Millennium bridge (2002) where wind effects or other induced vibrations matched the bridge span’s natural frequency. If the above bridges had been constructed differently, they would probably not have suffered as they did.
Vortex shedding is a genuine and serious potential problem that can significantly decrease fatigue life or substantially increase material stresses. The vortex shedding calculator gives you the ability to predict the likelihood of this occurring in your structural element and under your specified conditions.
Calculator
The vortex shedding calculator determines whether or not a beam will vibrate at its natural frequency in specified conditions.
The vortex shedding calculator applies equally well to any sectional shape so long as the correct properties including added mass and drag coefficients are applied to the input data.
Given that no more than two mode types will occur between two supports in any multimode vibration (see CalQlata’s Mode Shapes calculator), Vortex Shedding allows you to calculate the likelihood of vortex shedding in two modes at the same time.
Whilst Vortex Shedding is a standalone calculator, it has been designed to work with CalQlata's Waves and Mode Shapes calculators.
For help using this calculator see Technical Help
Vortex Shedding Calculator  Options
For all of the calculation options, the input and output data are as follows:
You enter: 
and the vortex shedding calculator will provide: 


Reynolds number

Strouhal number

KeuleganCarpenter number

Vortex frequency

Lift coefficient

Vortex lift force @ ƒₒ

Drag force

Available cycling force

Dynamic amplitude

Mode reduced velocity

Mode vortex shedding (inline)

Mode vortex shedding (crossflow)

Cycling force to achieve @ ƒn

Maximum expected bending moment

Stability parameter

# these values are only used for Oscillating Flow
Vortex Shedding includes a data import facility from CalQlata's Waves and Mode Shapes calculators
Check minimum system requirements