ON THE MECHANISM OF INTERACTION BETWEEN VIBRATIONS AND HEAT TRANSFER
Abstract
Several hypotheses have been proposed in the literature to explain the physical mechanism whereby transverse vibrations increase the rate of heat transfer by free convection from horizontal cylinders. A discussion is presented of the validity of these hypotheses in the light of recent experimentl data. The increase in the heat-transfer rate from a heated horizontal cylinder subjected to transverse horizontal vibrations is caused by thermoacoustic streaming. The increase is greatest on the upper half of the cylinder due to the action of the oscillating vortex flow which develops in this region at high intensities of vibration. The heat-transfer rate also increases on the lower half of the cylinder, where the flow is laminar. In the laminar region the rise in the rate of heat transfer appears to be caused by oscillations within the boundary layer similar to the effect of free-stream turbulence on the rate of heat transfer from a cylinder in cross-flow. The critical intensity of vibraions is approximately 0.3 ft/sec for vertical as well as for horizontal transverse vibrations of a heated horizontal cylinder. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1961
- Accession Number
- AD0275773
Entities
People
- R.m. Fand
Organizations
- Massachusetts Institute of Technology