The Influence of Sound on Free Convection From a Horizontal Cylinder

In a previous publication the authors described a new type of acoustic streaming, called thermoacoustic streaming, which occurs near a heated horizontal cylinder in the presence of horizontal transverse sound fields. In the present paper, quantitative experimental results are presented, which show that thermoacoustic streaming causes a marked increase in the coefficient of heat transfer from a heated cylinder; for a given temperature potential, the superposition of a sound field can increase the heat-transfer coefficient by a factor of 3, relative to the free-convection heat-transfer coefficient in the absence of sound. An empirical equation is provided by means of which the coefficient of heat transfer from a horizontal cylinder in the presence of horizontal transverse sound fields can be computed for many cases of practical interest.