Studies of Heat Transfer in Complex Internal Flows.
Abstract
Experiments have been performed to determine the heat transfer and pressure drop response of heat exchange devices subject to highly complex fluid flows. Three research problems were undertaken and completed, each dealing with different aspect of heat exchanger performance. In one case, per-tube transfer coefficients were measured in a tube bank in the presence of abrupt upstream enlargement of the flow cross section. Enhancement of the heat transfer was found to occur as a result of the flow disturbance caused by the enlargement. In the second research problem, the effect on heat transfer of the competition between tubes which draw air from a common plenum was investigated. This competition resulted in a skewing of the flow entering the tubes. Significant effects of the skewing occurred when the tubes were relatively close together (pitch approx. 1.5 tube diameters), but for larger spacings the heat transfer coefficients were virtually identical to those for a single tube. In the last of the problems, the effects of flow maldistribution caused by partial blockage of the inlet of a flat rectangular duct were investigated. Large spanwise nonuniformities of the local heat transfer coefficient were induced by the maldistributed flow. The spanwise average heat transfer coefficients in the downstream portion of the duct were found to be enhanced due to flow maldistribution, whereas at more upstream locations a reduction of the coefficients occurred. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1983
- Accession Number
- ADA124017
Entities
People
- E. M. Sparrow
Organizations
- University of Minnesota