Numerical Study of Nanofluid Irreversibilities in a Heat Exchanger Used with an Aqueous Medium

Ovando-Chacon, Guillermo Efren; Ovando-Chacón, Sandy Luz; León, Abelardo Rodríguez; Díaz-González, Mario; Hernandez-Zarate, Jorge Arturo; Servin-Martinez, Alberto

doi:10.3390/e22010086

Cited by 4 publications

(2 citation statements)

References 43 publications

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“…The numerical code was developed using the Fortran programming language, in the thermofluid group of the Technological Institute of Veracruz. The numerical code has previously been used to solve various thermofluid problems [ 40 , 41 , 42 , 43 ].…”

Section: Methodsmentioning

confidence: 99%

Computational Study of Thermal Comfort and Reduction of CO2 Levels inside a Classroom

Ovando-Chacon

León

Ovando-Chacón

et al. 2022

IJERPH

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Due to the current COVID-19 pandemic, guaranteeing thermal comfort and low CO2 levels in classrooms through efficient ventilation has become vitally important. This study presents three-dimensional simulations based on computational fluid dynamics of airflow inside an air-conditioned classroom located in Veracruz, Mexico. The analysis included various positions of an air extractor, Reynolds numbers up to 3.5 × 104, four different concentrations of pollutant sources, and three different times of the day. The simulations produced velocity, air temperature, and CO2 concentrations fields, and we calculated average air temperatures, average CO2 concentrations, and overall ventilation effectiveness. Our results revealed an optimal extractor position and Reynolds number conducive to thermal comfort and low CO2 levels due to an adequate ventilation configuration. At high pollutant concentrations, it is necessary to reduce the number of students in the classroom to achieve safe CO2 levels.

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Section: Methodsmentioning

confidence: 99%

Computational Study of Thermal Comfort and Reduction of CO2 Levels inside a Classroom

Ovando-Chacon

León

Ovando-Chacón

et al. 2022

IJERPH

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“…Thus, to find this optimal performance and to be able to specify the effects of the flow control parameters on thermal performance, we define a dimensionless number called the performance evaluation criterion (PEC). It is expressed as the ratio of the average Nusselt number to the total entropy generation (Ovando-Chacon et al , 2020; Gupta and Nayak, 2018; Torabi et al , 2016): …”

Section: Physical Model and Governing Equationsmentioning

confidence: 99%

Thermal performance analysis of hybrid nanofluid natural convection in a square cavity containing an elliptical obstacle under variable magnetic field

Belhaj

Ben-Beya

2021

HFF

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Purpose This study aims to analyze entropy generation and magnetohydrodynamic (MHD) natural convection of hybrid nanofluid in a square cavity, with a heated elliptical block placed at the center, in presence of a periodic-variable magnetic field. Design/methodology/approach In this paper, simulations were performed with a FORTRAN home code. The numerical methodology used to solve Navier–Stokes, energy and entropy generation equations with corresponding boundary conditions, is essentially based on the finite volume method and full multigrid acceleration. Findings The cavity is filled with Ag–Tio2/Water hybrid nanofluid. The main objective of this investigation is to predict the effects of body’s size (6 cases), type of applied magnetic field (variable or uniform), the non-dimensional period number of the variable magnetic field (VMF) (0.2 ≤ Λ ≤ 0.8), the inclination angle of the VMF (0 ≤ χ ≤ 90), Rayleigh number (5 × 103 ≤ Ra ≥ 105) and Hartmann number (5 ≤ Ha ≥ 100) on thermal performance, heat transfer rate, entropy generation and flow patterns. Originality/value To the authors’ best knowledge, this paper is the first numerical investigation deals with the entropy generation and natural convection of hybrid nanofluid in a two-dimensional cavity, with specific thermal boundary conditions, containing an elliptical block under periodic-variable magnetic field. Different combinations between flow-governing parameters were made to find optimal thermal performance.

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Effectiveness of a Shell and Helically Coiled Tube Heat Exchanger Operated With Gold Nanofluids at Low Concentration: A Multi-Level Factorial Analysis

Fogaça

Dias

Gómez

et al. 2021

Journal of Thermal Science and Engineering Applications

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This work assesses the thermal performance of gold nanofluids as cooling liquid in a shell and helically coiled tube (SHCT) heat exchanger built in bench-scale. Tests planned under a multi-level factorial experimental design were carried out to evaluate the effects caused by the volumetric fraction of the gold nanoparticles, the volumetric flow rate of the working fluid and the inlet temperature of the hot fluid (water) on the SHCT heat exchanger effectiveness. Spherical gold nanoparticles with mean diameter of 14±2 nm were produced from the Turkevich's method to be used in two concentrations of about 10-5 %vol. The heat transfer tests were performed at volumetric flow rates of 20, 30 and 40 L/h for both working fluids using heated water at inlet temperatures of 40, 50 and 60°C. Results showed that the less concentrated nanofluid was comparatively more efficient, suggesting the presence of a range of values of the gold concentration for the existence of an improvement on the effectiveness in the heat transfer.

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Numerical Study of Nanofluid Irreversibilities in a Heat Exchanger Used with an Aqueous Medium

Cited by 4 publications

References 43 publications

Computational Study of Thermal Comfort and Reduction of CO2 Levels inside a Classroom

Computational Study of Thermal Comfort and Reduction of CO2 Levels inside a Classroom

Thermal performance analysis of hybrid nanofluid natural convection in a square cavity containing an elliptical obstacle under variable magnetic field

Effectiveness of a Shell and Helically Coiled Tube Heat Exchanger Operated With Gold Nanofluids at Low Concentration: A Multi-Level Factorial Analysis

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