Author(s): Hossein Kheirkhah Gildeh; Abdolmajid Mohammadian; Ioan Nistor

Linked Author(s): Ioan Nistor, Majid Mohammadian, Hossein Kheirkhah Gildeh

Keywords: Effluent; Discharge; Turbulence; OpenFOAM; Shallow water; Plume; RANS

Abstract: Increasing numbers of seawater desalination plants are being designed and constructed around the world. This paper highlights findings from discharging effluents in shallow waters where jets plunge into the water surface. Vertical jets plunging into the water surface were investigated numerically (for the first time, to the best knowledge of authors) against the experimental results from Ahmad and Suzuki (J Water Sci & Tech, 2016). This study focuses on the worst-case scenario in terms of mixing and dilution of such jets: vertical dense effluent discharges with no ambient current and in shallow water where jet impacts the surface. Turbulent vertical discharges with Froude numbers ranging from 9 to 24 were simulated using OpenFOAM. Three flow regimes were reproduced numerically, based on the experimental data: deep, intermediate and impinging flow regimes. Five Reynolds-averaged Navier-Stokes (RANS) turbulence models were examined in a prior study (Gildeh et al., J Env. Fluid Mech., 2021): realizable k-ε and k-ω SST models (known as two-equation turbulence models), v2f (four equations to model anisotropic behavior) and LRR and SSG turbulence models (known as Reynolds stress models - six equations to model anisotropic behavior). Among those five models, it was concluded that LRR turbulence model performs the best and thus it has been selected for this study. This model performed reasonably well in replicating the experimental results.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0759-cd

Year: 2023