Length to Diameter Ratio and Row Number Effects in Short Pin Fin Heat Transfer

Abstract

Recently, several experiments concerning heat transfer from short pin fins have been conducted with the results indicating lower heat transfer from short pin fins than from longer pin fins found in tube banks and other similar configurations. Assessments of the effect of the number of pin rows and row geometry have also been made. It was felt that there was a need to determine the relative contribution of pin length to diameter ratio and pin row geometry on the heat transfer. Array-averaged heat transfer coefficients on pin and endwall surfaces were measured for two configurations of staggered arrays of short pin fins (length to diameter ratio of 4). One configuration contained eight streamwise rows of pins, while the other contained only four rows. Results showed that both the eight-row and the four-row configurations for an Lp/D of 4 exhibit higher heat transfer than in similar tests on shorter pin fins (Lp/D of 1/2 and 2). It was also found that for this Lp/D ratio the array-averaged heat transfer was slightly higher with eight rows of staggered pins than with only four rows.

Heat Transfer From Low Aspect Ratio Pin Fins

“…In a review article of staggered pin fin array heat transfer, Armstrong and Winstanley [1988] presented data by Brigham and VanFossen [1984] addressing the effect of pin fin aspect ratio on array averaged heat transfer. The results are shown in More resolution may be required to fully answer the question of the effect of aspect ratio on pin fin array heat transfer.…”

Performance Analysis of Perforated Cylindrical Pin-Fin Arrays in a Rectangular Duct

“…where, t in and t out are the temperatures of air flow, t b is the average temperature at certain designated locations on the base assembly and A s is the total surface area of base assembly and fins, which is given as, (4…”

“…To increase heat transfer and reduce fluid flow loss due to the pin-fin arrays, it is needed to understand the physical mechanisms that govern the heat transfer and pressure drop parameters. Earlier studies on pin-fin arrays were studied by Sparrow et al [4] and Tahat [5]. They experimentally investigated in-line and staggered pin-fin arrays fixed in an internal cooling channel.…”

Performance of Wire Springs as Extended Heat Transfer Surface for Compact Heat Exchangers

“…which is often used as a characteristic length for pin fins (9) or screen meshes (10) . Based on this characteristic length, Reynolds number, friction factor and Nusselt number are defined as follows.…”