dc.description.abstract |
The rectangular channel louvered-fin compact heat exchanger (LFCHE) is the most
efficient heat exchanger fin that has been used as a radiator fin. However, with this sort
of heat exchanger, the pressure drop rises by three to four times as the heat transfer
increases, which results in decreased performance. This research is aimed to
numerically investigate the louver edges (vertical, inclined, and horizontal) and slant
angle effect on the performance of LFCHE at different louver angles with air inlet
velocity ranging from 1-30 m/sec (97 < 𝑆𝑓
𝑚𝑞
< 2917), using CFD. Selection of the
computational domain, mesh independence test and validation of the base model with
previous work was done before the investigation. First, the edge effect and then the
slant angle effect was investigated and compared with the base (inclined edge) model.
Totally 24 domain models were made. The result revealed that horizontally edged
LFCHE decreased the pressure drop up to 24.2 % with a 1.01% increase in the outlet
air temperature over the base (inclined edge) model. Thus, compared to the pressure
drop, the temperature change is slighter effective on the louver edges. Based on the
criteria for performance evaluation (PEC), the horizontally edged depicted a higher
performance as compared to other louver edges, and at 10m/sec (𝑆𝑓
𝑚𝑞
= 972.33) the
horizontal edge increases the volume goodness (jf) factor up to 21.49% over the base
model. Moreover, for all louver angles, the horizontal edge behaves best jf-factor.
Better performance was recorded for the horizontally edged fin at a louver angle of 24Β°
at low 𝑆𝑓
𝑚𝑞
and 20Β° at high 𝑆𝑓
𝑚𝑞
which increased the jf-factor by 22% and 25%,
respectively. The effect of slant angle was investigated based on the best-performed
edge and the result revealed that at a slant angle of 6Β° the jf-factor increased up to
13.89 % at a low 𝑆𝑓
𝑚𝑞
. Moreover, it was seen that the slant angle effect was less
significant on the performance at a high 𝑆𝑓
𝑚𝑞
. Generally, the horizontally edged and
slanted LFCHE has a great performance in cooling the coolant with a minimum
pressure drop on the air side.
Keywords: Compact heat exchanger, friction factor, louver edge effect, louver fin,
slant angle, volume goodness factor |
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