Computational investigation into heat transfer coefficients of randomly packed pebbles in flowing FLiBe
| Autor: | Maolong Liu, Yacine Addad, Jeong-Ik Lee, Seong Gu Kim, Youho Lee |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Fluid Flow and Transfer Processes
Materials science business.industry Mechanical Engineering FLiBe Reynolds number 02 engineering and technology Heat transfer coefficient Mechanics Computational fluid dynamics 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 010305 fluids & plasmas Normal distribution chemistry.chemical_compound symbols.namesake chemistry 0103 physical sciences Shear stress symbols 0210 nano-technology business Reynolds-averaged Navier–Stokes equations Pebble |
| Zdroj: | International Journal of Heat and Mass Transfer. 145:118769 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2019.118769 |
| Popis: | Using CFD simulations, this study presents: (1) LES and RANS comparisons for a unit cell geometry of heat transferring pebbles in flowing FLiBe; (2) statistical distributions of pebble heat transfer coefficients due to the random packing; (3) development of a heat transfer coefficient correlation for randomly-packed heat transferring pebbles in flowing FLiBe in the representative Fluoride High-temperature Reactor (FHR) operating condition; and (4) comparison of the developed heat transfer coefficient correlation with existing ones obtained in different fluids and pebble sizes. The LES and RANS comparison has shown that the k-ω Shear Stress Transport (SST) with low Reynolds number approach performance gives the best result in comparison to the two eddy-viscosity based k-e and k-ω SST models. The statistical distribution of pebble heat transfer coefficients due to random packing has been quantified; random arrangements of pebbles result in non-negligible uncertainties in heat transfer coefficients following normal distributions. This uncertainty needs to be accounted for fuel temperature prediction in reactor design and analyses. A Nusselt number correlation for the randomly packed heat transferring pebble in flowing FLiBe has been computationally developed: Nu = 0.016Re0.72Pr0.31. |
| Databáze: | OpenAIRE |
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