Heat transfer from in-line and perpendicular arrangements of cylinders in steady and pulsating crossflow
Abstract
An investigation was conducted to determine the effect of organized
flow pulsations on mean heat transfer from a single cylinder, in-line
arrangements and perpendicular arrangements of cylinders. Pulsation
frequencies of up to twice the natural vortex shedding frequency and zero
to peak. amplitudes as high as 36 percent were used. Pulsations were
sinusoidal with at least 93 percent of the power at the fundamental frequency. Turbulence levels (Tu=0.5 percent) were not altered by the addition
of unsteady flow. Reynolds number ranged from 23,000
Mean heat transfer was found to increase for all three arrangements
when organized flow pulsations were applied. For a single cylinder and
for perpendicular arrangements, heat transfer increases were found primarily
on the back of the cylinder. For in-line arrangements, increases
occurred mostly on the front of the cylinder. for the range of pitch ratio most useful to heat exchanger design, in-line arrangements were
found to have a higher Nusselt number than perpendicular arrangements.
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- Masters Theses [19412]