Effect of Tip-to-Shroud Clearance on Turbulent Heat Transfer From a Shrouded, Longitudinal Fin Array

Abstract

Experiments were performed to determine the response of the heat transfer from a longitudinal fin array to the presence of clearance between the fin tips and an adjacent shroud. During the course of the experiments, the clearance was varied parametrically, starting with the no-clearance case; parametric variations of the fin height and of the rate of fluid flow through the array were also carried out. Air was the working fluid, and the flow was turbulent. The fully developed heat transfer coefficients corresponding to the presence and to the absence of clearance were compared under the condition of equal air flowrate, and substantial clearance-related reductions were found to exist. For clearances equal to 10, 20, and 30 percent of the fin height, the heat transfer coefficients were 85, 74, and 64 percent of those for the no-clearance case. The ratio of the with-clearance and no-clearance heat transfer coefficients was a function only of the clearance-to-fin-height ratio, independent of the air flowrate, the fin height, and the fin efficiency model used to evaluate the heat transfer coefficients. The presence of clearance slowed the rate of thermal development in the entrance region.

A numerical study of entry region laminar mixed convection over shrouded vertical fin arrays

“…Sparrow et al [13], Sparrow and Beckley [14], Sparrow and Kadle [15], and Kadle and Sparrow [16] performed investigation on the effect of heat transfer in the presence of fin-tip clearance under forced convection situation. Results obtained from these investigations showed a close relation between heat transfer coefficient ratio and fin-tip clearance to fin-height ratio, but found hardly any dependence on the air flow rate and fin height.…”

Modeling of the thermal and hydraulic performance of plate fin, strip fin, and pin fin heat sinks-influence of flow bypass

“…However, in order to reduce computational time, interest has also turned to development of compact models of the different heat sink types. The performance of plate fin heat sinks have been studied extensively by Sparrow and co-workers [1]- [3], Kadle and Sparrow [4], Lau and Mahajan [5], Wirtz and co-workers [6], [7], Iwasaki et al [8], Sata et al [9], and Jonsson and Moshfegh [10], [11]. The investigators have utilized experimental and/or numerical methods for both laminar and turbulent flow regimes.…”

A computational study of mixed convective heat and mass transfer from a shrouded vertical non-isothermal fin array during dehumidification process

“…Basic assumption involved in those analytical studies is the constant heat and mass transfer coefficient. As shown by Sparrow et al [10], Kadle and Sparrow [16], Sparrow and Kadle [17] heat transfer coefficient varies significantly over the fin height for the case of pure heat transfer. The case of simultaneous heat and mass transfer is not different.…”