Effect of Location in an Array on Heat Transfer to a Short Cylinder in Crossflow

Abstract

An experiment was conducted to measure the heat transfer from a heated cylinder, three diameters in length, in crossflow in an array of identical circular cylinders. Both in-line and staggered array patterns were studied. The cylinders were spaced on a 2.67 × 2.67 pitch. The Reynolds number range, based on cylinder diameter and average unobstructed channel velocity, was from 5000 to 125,000. Turbulence intensity profiles were measured for each case at a point one-half space upstream of the row containing the heated cylinder. The basis of comparison for all the heat transfer data was the single row with the heated cylinder. For the in-line cases, the addition of a single row of cylinders upstream of the row containing the heated cylinder increased the heat transfer by an average of 50 percent above the base case. Adding up to five more rows caused no increase or decrease in heat transfer. On the other hand, adding rows in the staggered array cases resulted in average increases in heat transfer of 21, 64, 58, 46, and 46 percent for one to five upstream rows, respectively.

Heat Transfer From Low Aspect Ratio Pin Fins

“…The only exception found is Simoneau and VanFossen [1984], who studied the pin fin heat transfer on a single row of It is also most common in the literature to focus heat transfer measurements directly within the pin fin array and not on the endwall upstream and downstream of the pin fins. Although the measurements were confined to a narrow strip 0.5 pin diameters long in the streamwise direction, Uzol and Camci [2005] studied the endwall heat transfer downstream of pin fin arrays.…”

“…Using the Reynolds number definition mentioned above, Simoneau and VanFossen [1984] reported that the pin heat transfer on the single pin was only 7 to 15% lower than the pin heat transfer of the row with S/d = 2.67 pin spacing. However, the velocity ratio between the two cases was 1.55.…”

“…While the heat transfer did reach a maximum at about the third row, the enhancement level remained nearly constant for rows farther downstream. Simoneau and VanFossen [1984] also studied the row by row variation of heat transfer on the pin surface for both inline and staggered arrays of pin fins. Both arrays had an S/d = X/d = 2.67, and H/d = 3 geometry.…”

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

“…3). The addition of one or more rows of pins in an inline pattern upstream of the measuring pin increased the heat transfer by about 50 percent, independent of the number of upstream rows.…”

A Review Paper on CFD Simulation of Square Threaded & Helical Twisted Pin Fin Arrays in a Rectangular Channel to Enhance Heat Transfer

“…Matsumoto et al [19] studied the end wall heat transfer in the presence of inline and staggered adiabatic circular pin fins. A review of staggered array pin fin heat transfer for turbine cooling applications was presented by Armstrong and Winstanley [20]. Bayram Sahin, Alparslan Demir [2] studied the heat transfer enhancement and pressure drop over a flat surface equipped with square crosssectional and modification as perforated pin fins in a rectangular channel.…”