3945 -- A Model for the Prediction of the Performance of a Spined-Tube-Absorber---Part 2: Model and Results PDF

A model for the heat and mass transport on a vertically oriented spiny tube is developed based on the dimensional analysis given in part 1. It is shown that when the influence of surface tension is neglected between the spines, there is an enhancement of the mass transfer rate to the liquid film; however, the enhancement is not large. It is suggested that the enhancement is due to the generation of a variation of the mass fraction on the local spine scale. The influence of the coolant flow is incorporated as well, and the model may thus be used in conjunction with a cycle analysis to determine whether given absorber states may be attained. Experimental results show that the pitch of the spines is decreased, the performance of the tube is significantly degraded and the spines actually inhibit mass transfer. A physical reason for this, based on the influence of surface tension through capillary effects, is advanced.

KEYWORDS: year 1996, calculating, performance, absorbers, heat flow, tubes, surface tension, fluid flow, experiment, pitch, comparing, finned tubes