University of Leicester
Browse

Large Eddy Simulation and Turbulence Model Assessment for Buoyant Flow in a Thermal Energy Storage Tank

journal contribution
posted on 2025-01-23, 12:27 authored by Xiao-Wei Xu, Ali Haghiria, Richard Sandberg, Takuo Oda, Koichi Tanimoto

Single-medium thermal energy storage is widely used for heat and cooling supply. During the charging and discharging process via jet nozzles, strong transient turbulent mixing and heat transfer occurs. Hence, qualitative and quantitative understanding on the thermal mixing mechanisms are beneficial to the design and operation of the thermal storage system. In this study, we perform large eddy simulation (LES) of a three-dimensional stratified water storage tank with a single jet issuing hot water to study the long-time behaviour. The simulation data are utilised to investigate the flow and thermal characteristics of the tank, especially the formation of the buoyant jet and the thermal dispersion along the vertical direction. It is shown that the fine vortical jet shear-layer structures are responsible for most of the turbulence mixing. Furthermore, the LES results are regarded as reference data for assessing the flow predictions that result from different solver set-ups and turbulence models employed in unsteady Reynolds averaged Navier–Stokes (URANS) calculations. The results demonstrate that the realisable model can yield satisfactory predictive accuracy, once the buoyant production is correctly included in both transport equations. Finally, we examine the effect of different choices of turbulence heat flux models, including the standard/generalised gradient diffusion hypothesis (SGDH and GGDH) and algebraic heat flux model (AFM), on the numerical predictions. The results indicate that the URANS with GGDH and AFM can accurately and efficiently predict the flow and thermal fields in the turbulent flow regime.

Funding

Funding from the Australian Research Council (ARC) is acknowledged, through the linkage project LP180100712 and the future fellowship FT190100072.

History

Author affiliation

College of Science & Engineering Engineering

Version

  • AM (Accepted Manuscript)

Published in

Flow, Turbulence and Combustion

Publisher

Springer Science and Business Media LLC

issn

1386-6184

eissn

1573-1987

Copyright date

2024

Available date

2025-12-12

Language

en

Deposited by

Mr Ali Haghiri

Deposit date

2024-12-17

Usage metrics

    University of Leicester Publications

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC