EXPERIMENTS ON THE TRANSFER CHARACTERISTICS OF A CORRUGATED FIN AND TUBE HEAT EXCHANGER CONFIGURATION.

Local and average air-side transfer coefficients were measured for a one-row corrugated fin and tube heat exchanger configuration. The measurements were accomplished via the heat-mass transfer analogy in conjunction with the naphthalene sublimation technique. The local transfer coefficients revealed the presence of several vortex systems which are activated and strengthened with increasing Reynolds number. The vortices serve to augment the transfer coefficients. The windward or leeward orientation of the facets of the corrugated wall was found to have a decisive effect on the transfer characteristics, with appreciably higher transfer rates prevailing on the windward facets. The average transfer coefficients were compared with those for a corresponding plane-walled heat exchanger configuration. The comparison showed that the augmentation due to the corrugated fin surface increased with Reynolds number. At a Reynolds number of 1000, the average coefficient for the corrugated fin system was about 45 percent greater than that for the plane fin system.