Abstract:
In this article, alumina/water nanofluid (NF) flow in a heatsink (H-S) with wavy
microchannels (W-MCs) is simulated. The H-S is made of aluminum containing four
similar parts. Each part has an inlet and outlet. Constant heat flux is applied on the
bottom of the H-S. The study is based on two-phase (T-P) mixture and single-phase (S-P)
models to determine the difference between these two types of simulations. FLUENT
software and the control volume method were used for simulations. The volume control
method is employed to solve equations. The effective variables include the volume fraction
0 < φ < 5% of alumina and Reynolds number (Re) 300 < Re < 1800. The maximum H-S
bottom temperature, the required amount of pumping power (PP), the temperature
uniformity, and the heat resistance of the H-S are the outputs studied to simulate the
S-P and T-P models. The results show that the use of the T-P model has less error in
comparison with the experimental data than the S-P model. An increment in the Re and φ
reduces the maximum temperature (M-T) of the H-S. The S-P model, especially at a higher
value of φ, leads to a lower M-T value than the T-P model. The S-P model shows a 0.5%
greater decrease than the T-P model at the Reynolds number of 300 by enhancing the
volume percentage of nanoparticles (NPs) from 1 to 5%. Temperature uniformity is
improved with Re and φ. The reduction of H-S thermal resistance with Re and φ is the
result of this study. Adding NPs to water, especially at higher amounts of φ, enhances the
required PP. The T-P model predicts higher PP than the S-P one, especially at a high value
of φ. The T-P model shows 4% more PP than the S-P model at Re 30 and a volume
fraction of 4%.
