The effect of sound on the heat transfer and the vortex-shedding from a heated circular cylinder: Acoustical vibrations directed along its axis

An experimental investigation has been carried out to study acoustic interferences in the heat transfer and the vortex-shedding from a heated circular cylinder in a crossflow subjected to the acoustic vibrations directed along the axis of the cylinder, and in particular, to measure the correlation of vortex-shedding along the cylinder axis. The results indicate that the effects of the acoustic vibrations directed along the asis of the cylinder are similar to the effects of the acoustic vibrations whose direction is normal to the axis of the cylinder on the vortex-shedding from the cylinder, and both vibrations increase the spanwise correlation of the cylinder wake. The acoustic frequencies which produce powerful effects on vortex-shedding correspond to the frequencies of laminar-turbulent transition wave in a separated shear layer, and there are critical sound pressure levels in these acoustic vibrations.