Scruton coil
A Scruton helix , also known as a Scruton spiral, is a flow-disrupting element that is attached to cylindrical objects that are in a flow . The name goes back to the inventor Christopher Scruton from Hampton near London , who in 1963 developed stabilization techniques for (building) structures exposed to wind currents at the National Research Development Corporation in London. A unit for mass damping parameters is named after him - the Scruton number .
functionality
If a cylindrical body is in a flow, turbulence occurs on the side facing away from the flow , which can cause the object to vibrate. The oscillation occurs at right angles to the wind direction. If the frequency of the oscillation meets the resonance frequency of the object, these oscillations rock up, which can lead to structural damage and, in the worst case, to complete destruction.
The Scruton coil is an edge that is wound helically around the cylinder. It breaks the current and diverts it in different directions. Since the eddies are no longer all created on the same side and their amplitude is lower, they can no longer set the object vibrating. However, in return, the flow resistance of the cylinder is increased.
Typical applications for the Scruton helix are high, free-standing pipes such as chimneys or antenna masts , but also holding ropes on large suspension bridges in areas prone to storms and the stiffening of container cranes. To protect against water currents and waves, support pillars of offshore production platforms are also surrounded by a helix.
Web links
- Scruton coil on an antenna mast
- Detailed description of eddy currents (European patent specification)