Heat transfer characteristics of a slot/slots jet
air impinging on a cylinder have been experimentally
investigated for two different orientations of slot/slots jet
plan with respect to cylinder axis. The experiments were
carried out to study the effects of orientation of slot/slots
jet plan with respect to cylinder axis on the rate of heat
transfer from the cylinder. Two different jet–cylinder
configurations were studied: (1) single slot jet aligned
with cylinder axis (slot length = cylinder length), and
(2) multiple slot jets equally spaces distributed orthogonal
to cylinder axis (each slot length = cylinder
diameter and sum of slots lengths = cylinder length).
For each configuration, parametric effects of Reynolds
numbers (Re) ranging from 1,000 to 10,000, dimensionless
slot widths (W/d) ranging from 0.125 to 0.5, and
dimensionless slot orifice-to-cylinder spacing (Z/W)
ranging from 1 to 12 on local and average Nusselt
numbers around cylinder surface have been investigated.
The results showed that: (1) cooling the cylinder by
multiple slots jets situated orthogonal to cylinder axis
gave more uniform surface temperature distributions
and higher heat transfer rate than the case of cooling the
cylinder by single slot jet aligned with cylinder axis, (2)
for both configurations the Nusselt number around the
cylinder increased with increasing Re and W/d, and (3)
for both configurations there was a certain Z/W in the
range 4