Investigations on the role of mixed convection and wall friction factor in single-phase natural circulation loop dynamics

Kumar, Naveen; Doshi, J. B.; Vijayan, P.K.

doi:10.1016/j.anucene.2011.06.004

Cited by 32 publications

(6 citation statements)

References 34 publications

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“…A number of applications of mixed convection involve electronic equipment cooling (Ghasemi, 2005; Radhakrishnan et al , 2009; Venkatachalapathy and Udayakumar, 2012; Ajmera and Mathur, 2015) to achieve enhanced heat transfer performance for smaller equipment size. A few recent applications also involve solar ponds, collectors and heaters (Tonui and Tripanagnostopoulos, 2008; Hobbi and Siddiqui, 2009), air cooling (Moraga and Lopez, 2004; Bianco et al , 2009; Minaei et al , 2014), heat exchangers (Voicu et al , 2007; Garoosi et al , 2015; Andrzejczyk and Muszynski, 2018; Bozor and Siavashi, 2019; Ren et al , 2019), desalination (Nasr et al , 2012; Pismenskiy et al , 2015), float glass production (Prieto et al , 2002; Antar et al , 2014) and nuclear reactors (Kumar et al , 2011; Cooper et al , 2016; Wang et al , 2017; Bieder et al , 2018). Mixed convection works may also be extended for non-Newtonian fluids (Yaseen and Ismael, 2020).…”

Section: Discussionmentioning

confidence: 99%

“…Various researchers also performed experimental works pertaining to mixed convection (Mansour and Viskanta, 1994; Chen and Cheng, 2004; Ji et al , 2007; Niu et al , 2007; Radhakrishnan et al , 2009; Venkatachalapathy and Udayakumar, 2012; Chen et al , 2012; Dogan and Sivrioglu, 2012; Ajmera and Mathur, 2015, 2016; Tian et al , 2018; Andrzejczyk and Muszynski, 2018; Contreras et al , 2019). The practical applications of mixed convection were explored in the earlier works (Prieto et al , 2002; Moraga and Lopez, 2004; Ghasemi, 2005; Voicu et al , 2007; Tonui and Tripanagnostopoulos, 2008; Bianco et al , 2009; Hobbi and Siddiqui, 2009; Kumar et al , 2011; Nasr et al , 2012; Antar et al , 2014; Minaei et al , 2014; Garoosi et al , 2015; Pismenskiy et al , 2015; Cooper et al , 2016; Wang et al , 2017; Bieder et al , 2018; Bozor and Siavashi, 2019; Ren et al , 2019).…”

Section: Introductionmentioning

confidence: 99%

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A comprehensive review on mixed convection for various patterns of kinematically and thermally induced scenarios within cavities

Lukose

Basak

2021

HFF

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Purpose The purpose of this paper is to address various works on mixed convection and proposes 10 unified models (Models 1–10) based on various thermal and kinematic conditions of the boundary walls, thermal conditions and/ or kinematics of objects embedded in the cavities and kinematics of external flow field through the ventilation ports. Experimental works on mixed convection have also been addressed. Design/methodology/approach This review is based on 10 unified models on mixed convection within cavities. Models 1–5 involve mixed convection based on the movement of single or double walls subjected to various temperature boundary conditions. Model 6 elucidates mixed convection due to the movement of single or double walls of cavities containing discrete heaters at the stationary wall(s). Model 7A focuses mixed convection based on the movement of wall(s) for cavities containing stationary solid obstacles (hot or cold or adiabatic) whereas Model 7B elucidates mixed convection based on the rotation of solid cylinders (hot or conductive or adiabatic) within the cavities enclosed by stationary or moving wall(s). Model 8 is based on mixed convection due to the flow of air through ventilation ports of cavities (with or without adiabatic baffles) subjected to hot and adiabatic walls. Models 9 and 10 elucidate mixed convection due to flow of air through ventilation ports of cavities involving discrete heaters and/or solid obstacles (conductive or hot) at various locations within cavities. Findings Mixed convection plays an important role for various processes based on convection pattern and heat transfer rate. An important dimensionless number, Richardson number (Ri) identifies various convection regimes (forced, mixed and natural convection). Generalized models also depict the role of “aiding” and “opposing” flow and combination of both on mixed convection processes. Aiding flow (interaction of buoyancy and inertial forces in the same direction) may result in the augmentation of the heat transfer rate whereas opposing flow (interaction of buoyancy and inertial forces in the opposite directions) may result in decrease of the heat transfer rate. Works involving fluid media, porous media and nanofluids (with magnetohydrodynamics) have been highlighted. Various numerical and experimental works on mixed convection have been elucidated. Flow and thermal maps associated with the heat transfer rate for a few representative cases of unified models [Models 1–10] have been elucidated involving specific dimensionless numbers. Originality/value This review paper will provide guidelines for optimal design/operation involving mixed convection processing applications.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A comprehensive review on mixed convection for various patterns of kinematically and thermally induced scenarios within cavities

Lukose

Basak

2021

HFF

View full text Add to dashboard Cite

show abstract

“…Moreover, a benchmarking problem statement known as natural convection in a cavity to validate the numerical approach has been carried out, and these results are presented in table A1 and figure A1, appendix. Further, the effectiveness and entropy generation in the loop have been estimated using correlations equations (22) to (26) [36].…”

Section: Validationmentioning

confidence: 99%

“…Various researchers effectively implemented various numerical methods to analyse the effect of the different parameters in studying the natural circulation loop. Naveen Kumar et al [22] conducted one-dimensional model simulation studies on natural circulation loops with horizontal water heaters in the loop for nuclear reactor application. The developed model has been used to study the oscillation of direction and thermal hydraulics phenomena in relation to the experimental data.…”

mentioning

confidence: 99%

Examining the potential of sigma-thermic heat transfer fluid and its nanofluid in a natural circulation loop through CFD studies

Nagaraju,

Mohammad,

Mendu

et al. 2024

Eng. Res. Express

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This study investigates the impact of hot heat exchanger (HHX) inlet temperature on Sigma-thermic heat transfer fluid (STHF or STF) performance in a natural circulation loop. Various fluids, including STHF and STHF-based nanofluids, with volumetric concentrations ranging from 0.5% to 3%, are employed in the loop. The primary objective is to analyze the thermal performance of the loop under different conditions, focusing on temperature distribution, Nusselt number, friction factor, effectiveness, and mass flow rate. 3D numerical simulations are conducted, and the numerical model is validated against existing literature. The developed model incorporates considerations for viscous dissipation and axial conduction to predict the heat transfer potential of the loop. As the HHX inlet temperature increases, the mass flow rate rises. Notably, STHF/CuO nanofluids exhibit a more substantial enhancement than other nanofluids. At a 1 vol% concentration, the mass flow rate increases by 9.5%, 4%, and 2.7% for STHF/CuO, STHF/Al2O3, and hybrid nanofluids, respectively, compared to pure STHF. The study reveals significant improvements in mass flow rates and heat transfer efficiency with increasing HHX inlet temperatures, especially with STHF/CuO nanofluids. The total entropy generation reduction is notable, with percentages ranging from 2% to 18.5% for various nanofluids compared to pure STHF

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“…During the start-up process, the working medium is heated up gradually and the heat will be transferred into the heat sink finally. Kumar et al (2011Kumar et al ( , 2014 presented a 1-D model to simulate the start-up process of the NCLs in which the heater and cooler are located in different positions. However, all the investigations only focus on the single-phase natural circulation loop dynamics.…”

Section: Introductionmentioning

confidence: 99%

Simulating investigations on the start-up of the open natural circulation system

Guo

Sun

Wang

et al. 2015

Nuclear Engineering and Design

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Investigations on the role of mixed convection and wall friction factor in single-phase natural circulation loop dynamics

Cited by 32 publications

References 34 publications

A comprehensive review on mixed convection for various patterns of kinematically and thermally induced scenarios within cavities

A comprehensive review on mixed convection for various patterns of kinematically and thermally induced scenarios within cavities

Examining the potential of sigma-thermic heat transfer fluid and its nanofluid in a natural circulation loop through CFD studies

Simulating investigations on the start-up of the open natural circulation system

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