1. Vortices are observed downstream of a 2-cm-diameter cylinder in 20-C atmospheric air. How far are the shed vortices apart downstream of the cylinder for an air speed of 5 m=s?
2. A sensor is positioned downstream a short distance from a 4-cm-diameter cylinder in a 20-C atmospheric airflow. It senses vortex shedding at a frequency of 0.16 Hz. Estimate the airspeed.
3. A 10-C wind blows over 6-mm-diameter high-tension wires. Determine the range of velocities over which vortex shedding occurs. Could the shedding frequency be heard? Humans with good hearing can hear frequencies between 20 and 20 000 Hz. (Such vortex shedding when ice coats the wires can cause ‘‘galloping'' where the wires actually oscillate from the usual catenaries to inverted catenaries resulting in wire failure.)