Optimizing of heat transfer and flow characteristics within a roughened solar air heater duct with compound turbulators

Jul 23, 2024

Journal Asian-Pacific Journal of Chemical Engineering

publisher WIlEY

DOI https://doi.org/10.1002/apj.3126

Issue 5

Volume 19

Thermal systems for solar air heating have been widely used in both industrial and residential contexts, and are essential for converting and recovering solar energy. Thermal performance in solar air heaters (SAHs) can be improved through the repetitive application of artificial roughness to the surfaces. This research work includes a numerical evaluation of SAH performance with artificial rough surfaces made up of combined transverse trapezoidal ribs and chamfered grooves. The ANSYS Fluent software version 2023 R1 was used to simulate SAH with varying relative roughness pitch ((Formula presented.)), relative roughness heights ((Formula presented.)), and Reynolds number ((Formula presented.)). The RNG (Formula presented.) model was chosen to forecast an enhancement in Nusselt number ((Formula presented.)), friction factor ((Formula presented.)), and thermohydraulic performance factor (TPF) for the proposed roughness. Out of multiple roughness parameters analyzed, it was determined that the compound turbulator with (Formula presented.) and (Formula presented.), were the most effective. The TPF for this scenario was determined to be 2.12 at (Formula presented.). Finally, a numerical based empirical correlations for (Formula presented.) and (Formula presented.) in terms of Re, (Formula presented.), and (Formula presented.) were developed. © 2024 Curtin University and John Wiley & Sons Ltd.

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CFD Analysis of Improving Air Conditioning System Performance by Adding SiO2 Nanoparticles to the Compressor Oil

Feb 1, 2025

Journal CFD Letters

publisher Semarak Ilmu Publishing

DOI 10.37934/cfdl.17.2.136147

Issue 2

Volume 17

The overall performance of air-conditioning systems is necessary to evaluate the comfort conditions and equipment life. in order not to varnish energy. The aim of this study is to improve performance of air conditioning by adding nanoparticles to oil of compressor. The research applied computational fluid dynamics CFD to simulate the use of SiO2 nanoparticles in air-conditioning systems. Silicon dioxide (SiO2) nanoparticles have better thermal properties than pure oil and can also significantly enhance the performance of compressor oils as well as heat transfer capability in HVAC systems. This research investigates the reactions between (0.1%, 0.4%, and %0.7) of SiO2 nanoparticles with compressor oil, to determine their impacts on heat dissipation, lubricant efficiency as well as performance overall. Results show that the addition of nanoparticles to the oil lubricant increases the COP of the air conditioning system.

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