This paper demonstrates a numerical study on heat transfer characteristics of
laminar flow in a double-layered oblique finned heat sink using nanofluids
with Al2O3 nanoparticles. Microchannel heat sink with primary channel width
of 0.5 mm with aspect ratio of 3 is employed. Instead of having conventional
straight fins, oblique fins with narrow secondary channels are used. In this
numerical study, single-phase fluid model with conjugate heat transfer is
considered. The numerical modelling was first validated with existing data
for double-layered conventional microchannel heat sink having water (base
fluid) as the working fluid. Numerical investigations on oblique finned
microchannel heat sink were then conducted for flow rates ranging from
3?10-7 to 15?10-7 m3/s, equivalent to primary channel inlet velocity in
between 0.2 and 1.0 m/s. It was found that double-layered oblique finned
configuration yields better heat transfer performance, inferred by the lower
overall thermal resistance obtained as compared with that of double-layered
conventional heat sink. Employing double-layered oblique finned heat sink,
the heat transfer performance could be further enhanced, by using
nanoparticles that are added into water-based fluid. It is found that the
reduction of overall thermal resistance is proportional to the volume
fraction of nanoparticles. Using cross flow double-layered oblique finned
configuration, the largest reduction in the overall thermal resistance can
reach up to 25%, by using nanofluids with 4% volume fraction of Al2O3
nanoparticles.
Numerical assessment on heat transfer performance of double-layered oblique fins microchannel heat sink with Al2O3 nanofluid
