Scaling Law of Flow and Heat Transfer Characteristics in Turbulent Radiative Rayleigh-Bénard Convection of Optically Thick Media DOI Creative Commons

Jiajun Song,

Panxin Li,

Lu Chen

et al.

Energies, Journal Year: 2024, Volume and Issue: 17(19), P. 5009 - 5009

Published: Oct. 8, 2024

Radiative natural convection is of vital importance in the process energy storage, power generation, and thermal storage technology. As attenuation coefficients many heat transfer media these fields are high enough to be considered as optically thick media, like nanofluids or molten salts concentrated solar phase change Rosseland approximation commonly used. In this paper, we delve into impact radiation on Rayleigh-Bénard (RB) convection. Theoretical analysis has been conducted by modifying Grossmann-Lohse (GL) model. Based turbulent dissipation theory, corresponding scaling laws four main regimes proposed. Direct numerical simulation (DNS) was also performed, revealing that exerts a notable influence both flow transfer, particularly formation large-scale circulation. By comparing with DNS results, it found due presence radiation, modified Nu law small Pr range GL model more suitable for predicting transport characteristics optical large Pr. The maximum deviation between results prediction about 10%, suggesting summarized can effectively predict radiative RB

Language: Английский

Enhancing PV System Modeling Accuracy: Comparative Analysis of Radiation Models and Data Sources DOI
Delnia Sadeghi, Akbar Eslami,

Shahab Eslami

et al.

Next research., Journal Year: 2025, Volume and Issue: unknown, P. 100165 - 100165

Published: Jan. 1, 2025

Language: Английский

Citations

2
Nanofluids and engineering applications: A review DOI Open Access
Hasan Donat Yıldızay, Muhammed Bekmezci, Fatih Şen

et al.

Journal of Scientific Reports-A, Journal Year: 2025, Volume and Issue: 060, P. 126 - 149

Published: March 25, 2025

With the development of technology, search for advanced materials has accelerated. Nanomaterials have emerged as an important material group in this and found a place themselves many different areas. Nanofluids, which are formed by dispersing nanoparticles basic liquids such water, ethylene glycol, or oils, very innovative method applications nanoparticles. They also wide range applications. The improved thermophysical properties nanofluids made research area engineering. Nanofluids gained unique area, especially cooling lubrication systems due to their higher thermal conductivity, viscosity, convective heat transfer compared traditional liquids. hold promises solar energy systems, defense industry nuclear plants, biomedical applications, automotive, aviation industries where efficient is important. It been shown that use processing processes increases product quality minimizes wear. Despite these benefits, problems stability, cost, long-term performance continue. These challenges continue be investigated with focus on optimizing nanoparticle concentration, developing dispersion methods, analyzing environmental impact nanofluids. Computational experimental studies will help understand flow behavior under operating conditions. aim paper review existing nanofluid studies. provides overview current developments field engineering, focusing functions transfer, industrial processes.

Language: Английский

Citations

0
Experimental and Numerical Study on Air Cooling System Dedicated to Photovoltaic Panels DOI Creative Commons

Maksymilian Homa,

Krzysztof Sornek, Wojciech Goryl

et al.

Energies, Journal Year: 2024, Volume and Issue: 17(16), P. 3949 - 3949

Published: Aug. 9, 2024

The efficiency of solar systems, in particular photovoltaic panels, is typically low. Various environmental parameters affect including sunlight, the ambient and module surface temperatures, wind speed, humidity, shading, dust, installation height, etc. Among others, key players are indeed irradiance temperature. higher temperature is, short-circuit current lower open-circuit voltage is. negative effect lowering dominant, consequently power panels. Passive or active cooling systems can be provided to avoid This paper presents a prototype an system dedicated photovoltaics. such was developed at AGH University Kraków tested under laboratory conditions. proposed equipped with air fans mounted on plate connected rear part 70 Wp panel. Different configurations were tested, different numbers locations fans. artificial light source generated irradiation value 770 W/m2. present for every variant experiment. As observed, maximum panel conditions approx. 47.31 W. Due increase, this reduced 40.09 W (when uncooled reached 60 °C). On other hand, 44.37 same (i.e., it by 10.7% compared that one). A mathematical model based results obtained, simulations carried out using ANSYS Workbench software. After validation procedure, several analyzed. most prominent case chosen additional parametrical analysis. optimum fan orientation recognized: vertical tilt 7° horizontal 10°. For module, modification resulted cost-effective (a net increase ~3.1%).

Language: Английский

Citations

1
Scaling Law of Flow and Heat Transfer Characteristics in Turbulent Radiative Rayleigh-Bénard Convection of Optically Thick Media DOI Creative Commons

Jiajun Song,

Panxin Li,

Lu Chen

et al.

Energies, Journal Year: 2024, Volume and Issue: 17(19), P. 5009 - 5009

Published: Oct. 8, 2024

Radiative natural convection is of vital importance in the process energy storage, power generation, and thermal storage technology. As attenuation coefficients many heat transfer media these fields are high enough to be considered as optically thick media, like nanofluids or molten salts concentrated solar phase change Rosseland approximation commonly used. In this paper, we delve into impact radiation on Rayleigh-Bénard (RB) convection. Theoretical analysis has been conducted by modifying Grossmann-Lohse (GL) model. Based turbulent dissipation theory, corresponding scaling laws four main regimes proposed. Direct numerical simulation (DNS) was also performed, revealing that exerts a notable influence both flow transfer, particularly formation large-scale circulation. By comparing with DNS results, it found due presence radiation, modified Nu law small Pr range GL model more suitable for predicting transport characteristics optical large Pr. The maximum deviation between results prediction about 10%, suggesting summarized can effectively predict radiative RB

Language: Английский

Citations

0