Numerical and experimental analysis of a planar jet with heated co-flow at medium and low Prandtl-number values

Research output: Contribution to journalArticle

Standard

Numerical and experimental analysis of a planar jet with heated co-flow at medium and low Prandtl-number values. / Cascioli, Edoardo; Buckingham, Sophia; Keijers, Steven; Van Tichelen, Katrien; Kenjeres, Sasa.

In: Nuclear Engineering and Design, Vol. 361, 110570, 18.04.2020, p. 1-11.

Research output: Contribution to journalArticle

Author

Bibtex - Download

@article{3dd5ab7a11614cb1b87be0f167395b06,
title = "Numerical and experimental analysis of a planar jet with heated co-flow at medium and low Prandtl-number values",
abstract = "In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA), currently under design at SCK•CEN. The present planar jet configuration mimics a closed wind tunnel that is designed and operated at VKI to generate an experimental database for velocity and temperature fields of a turbulent forced-convection flow regime. The performed experiments combine the Particle Imaging Velocimetry (PIV) (in characteristic planes) and thermocouple (single point) measurements. In parallel with experiments, comprehensive numerical simulations have been performed within the RANS modeling framework. Next to the standard eddy-viscosity based two-equation k − ε model, an extended variant based on the low-Reynolds elliptic relaxation concept (so-called ζ − f model) has been applied too. To investigate the low-Prandtl effects on the heat transfer, series of the turbulent heat transfer models have been applied, ranging from a conventional constant turbulent Prandtl number to a more elaborate kθ − εθ model. The combination of the low-Reynolds ζ − f and kθ − εθ models was explored for the first time in the content of nuclear engineering applications. The focus of the numerical studies is to address in details the effects of low-Prandtl fluid in the strongly forced convection flow (central planar cold jet) in presence of a strong shear (hot co- flow). We demonstrate the importance of the proper specification of the inlet boundary conditions in numerical simulations to mimic correctly experimentally observed asymmetrical distributions of the cross-wise profiles of stream-wise velocity, turbulent kinetic energy and temperature. Finally, the minor differences in results between the assumed constant turbulent Prandtl number and more advanced kθ − εθ model of the turbulent heat flux confirmed the overly dominant mechanisms of the strong convection and molecular diffusion in the present configuration.",
keywords = "Planar jet, Forced convection, Low prandtl number, Two-equation heat transfer model",
author = "Edoardo Cascioli and Sophia Buckingham and Steven Keijers and {Van Tichelen}, Katrien and Sasa Kenjeres",
note = "Score=10",
year = "2020",
month = "4",
day = "18",
doi = "10.1016/j.nucengdes.2020.110570",
language = "English",
volume = "361",
pages = "1--11",
journal = "Nuclear Engineering and Design",
issn = "0029-5493",
publisher = "Elsevier",

}

RIS - Download

TY - JOUR

T1 - Numerical and experimental analysis of a planar jet with heated co-flow at medium and low Prandtl-number values

AU - Cascioli, Edoardo

AU - Buckingham, Sophia

AU - Keijers, Steven

AU - Van Tichelen, Katrien

AU - Kenjeres, Sasa

N1 - Score=10

PY - 2020/4/18

Y1 - 2020/4/18

N2 - In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA), currently under design at SCK•CEN. The present planar jet configuration mimics a closed wind tunnel that is designed and operated at VKI to generate an experimental database for velocity and temperature fields of a turbulent forced-convection flow regime. The performed experiments combine the Particle Imaging Velocimetry (PIV) (in characteristic planes) and thermocouple (single point) measurements. In parallel with experiments, comprehensive numerical simulations have been performed within the RANS modeling framework. Next to the standard eddy-viscosity based two-equation k − ε model, an extended variant based on the low-Reynolds elliptic relaxation concept (so-called ζ − f model) has been applied too. To investigate the low-Prandtl effects on the heat transfer, series of the turbulent heat transfer models have been applied, ranging from a conventional constant turbulent Prandtl number to a more elaborate kθ − εθ model. The combination of the low-Reynolds ζ − f and kθ − εθ models was explored for the first time in the content of nuclear engineering applications. The focus of the numerical studies is to address in details the effects of low-Prandtl fluid in the strongly forced convection flow (central planar cold jet) in presence of a strong shear (hot co- flow). We demonstrate the importance of the proper specification of the inlet boundary conditions in numerical simulations to mimic correctly experimentally observed asymmetrical distributions of the cross-wise profiles of stream-wise velocity, turbulent kinetic energy and temperature. Finally, the minor differences in results between the assumed constant turbulent Prandtl number and more advanced kθ − εθ model of the turbulent heat flux confirmed the overly dominant mechanisms of the strong convection and molecular diffusion in the present configuration.

AB - In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA), currently under design at SCK•CEN. The present planar jet configuration mimics a closed wind tunnel that is designed and operated at VKI to generate an experimental database for velocity and temperature fields of a turbulent forced-convection flow regime. The performed experiments combine the Particle Imaging Velocimetry (PIV) (in characteristic planes) and thermocouple (single point) measurements. In parallel with experiments, comprehensive numerical simulations have been performed within the RANS modeling framework. Next to the standard eddy-viscosity based two-equation k − ε model, an extended variant based on the low-Reynolds elliptic relaxation concept (so-called ζ − f model) has been applied too. To investigate the low-Prandtl effects on the heat transfer, series of the turbulent heat transfer models have been applied, ranging from a conventional constant turbulent Prandtl number to a more elaborate kθ − εθ model. The combination of the low-Reynolds ζ − f and kθ − εθ models was explored for the first time in the content of nuclear engineering applications. The focus of the numerical studies is to address in details the effects of low-Prandtl fluid in the strongly forced convection flow (central planar cold jet) in presence of a strong shear (hot co- flow). We demonstrate the importance of the proper specification of the inlet boundary conditions in numerical simulations to mimic correctly experimentally observed asymmetrical distributions of the cross-wise profiles of stream-wise velocity, turbulent kinetic energy and temperature. Finally, the minor differences in results between the assumed constant turbulent Prandtl number and more advanced kθ − εθ model of the turbulent heat flux confirmed the overly dominant mechanisms of the strong convection and molecular diffusion in the present configuration.

KW - Planar jet

KW - Forced convection

KW - Low prandtl number

KW - Two-equation heat transfer model

UR - https://ecm.sckcen.be/OTCS/llisapi.dll/open/38220876

U2 - 10.1016/j.nucengdes.2020.110570

DO - 10.1016/j.nucengdes.2020.110570

M3 - Article

VL - 361

SP - 1

EP - 11

JO - Nuclear Engineering and Design

JF - Nuclear Engineering and Design

SN - 0029-5493

M1 - 110570

ER -

ID: 6784100