Contents lists available at ScienceDirect International Journal of Thermal Sciences journal homepage: www.elsevier.com/locate/ijts Advanced numerical modeling of turbulent ice slurry flows in a straight pipe Aurélien Bordet a , Sébastien Poncet a,* , Michel Poirier b , Nicolas Galanis a a Université de Sherbrooke, Faculté de génie, Département de génie mécanique, 2500 Boulevard de l’Université, Sherbrooke, QC, J1K 2R1, Canada b Ressources naturelles Canada (CanmetÉnergie), 1615 Lionel Boulet, Varennes, QC, J3X 1S6, Canada ARTICLE INFO Keywords: Ice slurry Numerical modeling Isothermal flow Turbulent dispersion ABSTRACT The present work aims at developing and assessing an advanced numerical model in order to investigate the dynamic behavior of ice slurry flows under isothermal conditions. The transport equation proposed by Phillips et al. [1] for solid suspension flows is used to describe the evolution of the particle volume fraction within the flow. For turbulent flows, an original term is introduced to account for the turbulent dispersion of the particles. The model has first been favorably compared to experimental data available in the literature for three types of solid-fluid suspensions. It is also shown that it provides more accurate predictions than more complex two-phase models. The numerical model has then been used confidently to investigate ice slurry flows. Four turbulence closures have been compared in a numerical benchmark. The results obtained by the − k ω SST model have then been compared for discussion to the analytical model of Kitanovski and Poredǒs [2] for eight sets of inlet flow conditions. The present model is able to capture more complex flow features, especially the secondary flow and the near-wall boundary layers. 1. Introduction Ice slurries are a complex mixture of liquid water, ice particles and a given additive used to lower the freezing point temperature of the mixture. Progressively, they become a competitive alternative to con- ventional secondary refrigeration systems due to the recent improve- ments in ice slurry generator technology. Companies can now manu- facture generators able to produce highly concentrated ice slurries without ice agglomeration, especially using seawater (see the recent review of Melinder and Ignatowicz [3]). As other phase changing media, ice slurry allows to store and transport a very large amount of “cold energy”. Egolf and Kauffeld [4] observed that the heat capacity of ice slurries is eight times higher than the heat capacity of traditional single-phase secondary refrigerants. For a given amount of transported energy, the pumping energy consumption is then drastically reduced compared to other secondary refrigerants and smaller equipment can be used. The reduced freezing point temperature of the mixture enables to improve the quality of the produced cold and to obtain a cooling pro- cess with almost no temperature change. Ice slurries contain a very small quantity of non-polluting additives, which makes them an effi- cient refrigeration technology with a low environmental impact. They have therefore been widely applied in various industrial applications going from building cooling to food conditioning, or even in medical protective cooling applications. The reader can refer to some review papers [4–7] for more details. More surprisingly, their local and/or time-dependent hydrodynamic behavior still remains not fully understood. The thermal insulation of the heat exchangers and the opacity of ice slurries, among other para- meters, make the measurements of local velocity, temperature or ice concentration difficult. During the last two decades, experiments con- cerned mainly global measurements: pressure loss, mass flowrate, wall temperatures or density among other things, both at the inlet and the outlet of heat exchangers. Various operating conditions were con- sidered in terms of flowrate, initial concentration of the additive and of the ice particles, type of additive, geometrical configuration, thermal boundary conditions … As examples, Renaud-Boivin et al. [8] per- formed experiments in a shell and tube heat exchanger with an ethylene glycol ice slurry flowing in the tubes and hot water in the shell and Kumano et al. [9] investigated the flow and heat transfer characteristics of ethanol ice slurry in the transition region. From experimental mea- surements of the flowrate and the pressure loss, other authors deduced rheological laws for ice slurry flowing in pipes [10] or more complex geometries [11]. Reviews on the thermophysical properties of ice slurry may be found in Refs. [4,12]. The lack of reliable local experimental data has slowed down the development of innovative and dedicated numerical models. Ice slurry flows are very challenging for numerical methods: multiphase flows, non-Newtonian behavior, thermal imbalance between the different https://doi.org/10.1016/j.ijthermalsci.2018.02.004 Received 13 March 2017; Received in revised form 26 November 2017; Accepted 6 February 2018 * Corresponding author. E-mail addresses: Aurelien.Bordet@USherbrooke.ca (A. Bordet), Sebastien.Poncet@USherbrooke.ca (S. Poncet), Michel.Poirier@canada.ca (M. Poirier), Nicolas.Galanis@USherbrooke.ca (N. Galanis). International Journal of Thermal Sciences 127 (2018) 294–311 1290-0729/ Crown Copyright © 2018 Published by Elsevier Masson SAS. All rights reserved. T