The thermal and economic characteristics of solar air collectors with different delta turbulators arrangement

Al‐damook

2019

Self Cite

Ever since the rapid increase in both the demand for the miniature electronic devices and their applications, heat dissipation in the electronic components has been a serious issue. A miniature plate‐pin heat sink model with square, circular, and elliptic pins is considered to enhance the hydrothermal performance of this kind of compact heat sink (CHS). Water and 3% of SiO2‐water nanofluids of volume fraction were used with different Reynolds number ranges (100‐1000). The findings show that the base temperature of heat sink reduces while the Nusselt number enhances by using nanofluids and increasing Reynolds number. The lowest value of the base temperature is nearly 25% for the square pins and circular pins CHSs compared with a plate–fin heat sink at 3% of nanofluids. Furthermore, the highest value of the Nusselt number is about 98% at 3% SiO2 for circular pin CHSs compared with the plate–fin heat sink. However, the pressure drop of CHSs is higher than that of plate–fin heat sink. Moreover, the most significant hydrothermal performance value is about 1.44 for water and around 1.51 for SiO2 as using the CHS with circular and elliptic pins depends on the Reynolds number. Thus, applying CHSs with nanofluids instead of the traditional heat sinks might produce a substantial enhancement in the hydrothermal performance of heat sinks.

Section: Resultsmentioning

confidence: 99%

The hydraulic‐thermal performance of miniature compact heat sinks using SiO₂‐water nanofluids

Fadhil

Al‐damook

2019

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“…The same experimental setup of the SAHs was used as in our previous publication work and is shown in Figure . A schematic diagram of the constructed single‐flow solar air heater collector with top and side views of the system is shown in Figure A and B, respectively.…”

Section: Experimental Work and Measurement Proceduresmentioning

confidence: 99%

Exergy analysis of single‐flow solar air collectors with different configurations of absorber plates

Obaid

Dawood

2019

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In the current study, an experimental analysis of exergy performance for different absorber plates is done. Three types of absorber plates are supplied with different fin arrangements with a variable air mass flow rate. The exergy analysis to evaluate the exergy performance of the solar air heaters uses experimental data for conventional and finned solar air collectors with different arrangements of fins. The main aim of the current study is to compare the exergy performance of the conventional solar air collector with those equipped with fins. The introducing of the fins in different arrangements enhances the absorber surface area, which leads to increased heat transfer. Also, fins induce air turbulence in the flow field, which improves the exergy performance of solar air collector. It is found that the exergy reduces and exergy efficiency enhances with increasing the airflow rate. The traditional flat absorber plate has undesirable exergy loss and exergy efficiency for all ranges of airflow rates. Thus, the flat plate collector presents the most substantial irreversibility, for which the exergy efficiency is the least. However, the results show that the exergy efficiency of inclined staggered turbulators is higher than that of in-line and staggered turbulators. The optimal value of exergy

“…Figure A shows no recirculation flow in the channel of heat sink due to no presence of pins, which leads to no separation fluid along the unpinned heat sink. However, recirculation flow appears due to using pins producing a proper mixing between the cold water layers itself and with the hot surface of pins and the thickness of the boundary layer diminishes over the heat sinks, as shown in Figure B‐F. Further recirculation and a substantial separation are monitored for SSPs (Figure B) and SPs (Figure C) and lead to an enlargement pressure drop.…”

Section: Resultsmentioning

confidence: 97%

Three‐dimensional computational comparison of mini pinned heat sinks using different nanofluids: Part one—the hydraulic‐thermal characteristics

Al‐damook

Alfellag

2019

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The hydraulic-thermal characteristics of 3D pinned heat sink designs have been numerically compared as the first part of a three-part investigation. Five different pin geometries (circular, square, triangular, strip, and elliptic pins) and an unpinned heat sink with three types of nanofluids (Al 2 O 3 -H 2 O, SiO 2 -H 2 O, and CuO-H 2 O) are considered for laminar forced convection. The range of Reynolds number is from 100 to 1000, and volume fractions vary between 0% and 5%.The finite volume method is employed to solve the Navier-Stokes and energy equations by employing a SIMPLE algorithm for a computational solution. Three parameters are presented-the Nusselt number, the bottom temperature, and the hydrothermal performance of the heat sink with pressure drop data. The findings indicated that the overall hydrothermal performance of elliptic-pinned (EP) heat sinks produces the most substantial value of 3.10 for pure water. For different nanofluids, the SiO 2 -water nanofluids with EPs have the most significant hydrothermal performance. Also, this factor is enhanced with an increase in nanofluid concentration up to nearly 3.34 for 5% of SiO 2 -water. Consequently, applying the elliptic-pinned heat sinks is recommended with pure water for considering an increase in the pressure drop, with 5% of SiO 2 -water nanofluids, regardless of an enlargement of pressure drop for heat-dissipation applications. K E Y W O R D Scooling rate enhancements, hydrothermal performance augmentation, pinned heat sinks, using different nanofluids 1 | INTRODUCTION Many cooling techniques have been suggested for improving the hydraulic-thermal performance of macro, mini, and micro heat sinks to overcome the main challenge of electronic cooling systems with a high density of heat generation. The improvement in the hydraulic thermal design of heat sink leads to a reduction in its size and weight and enhances the cooling rate; thereby, avoiding failure and increasing the reliability and speed performance of engineering devices. 1 Therefore, pinned heat sinks are one of the most common techniques used to improve the thermo-hydraulic performance of heat sinks because heat sinks with pins are applied in the liquid and gas processes of many engineering applications. Pinned heat sinks are proposed as a cooling technique with water and nanofluids to enhance the cooling performance of heat sinks. 1-3 Thus, many researchers have investigated different kinds of heat sinks with various fluid types to overcome the issue of rapidly developing heat generated in electronic systems and their applications for protecting these systems from damage.Many numerical studies on heat sinks with pins using liquid cooling have been performed. For example, Ambreen et al 4 reported the hydrothermal characteristics of circular micro-pinned heat sinks with Al 2 O 3 -H 2 O nanofluids (0.25%-1%) using the Lagrangian-Eulerian approach. The results showed that the hydrothermal performance was enhanced upon using nanofluids with an increase in volume fraction instead of pure wa...