Simulation of inclined dense jets in stagnant environments: an LES and experimental study

Large eddy simulation of sneeze plumes and particles in a poorly ventilated outdoor air condition: A case study of the University of Houston main campus

“…The resolution of the computational grid significantly impacts the outputs of LESs, and the set of indices known as “LES indices of Resolution Quality (LES_IQk)” can be used as criteria to assess the resolution quality of the simulation. One of the indices can be mathematically defined as the ratio of the resolved portion of the turbulent kinetic energy (TKE) to the overall TKE ( Tofighian et al, 2022 ), the equation for which is described in Eq. (18) : where is the fraction of resolved kinetic energy, the resolved kinetic energy, and the modeled sub-grid scale TKE; according to ( Celik et al, 2005 ; Pope, 2004 ), is suggested to be in the range of 0.77 ≤ ≤ 0.85.…”

Venturi nozzles for desalination brine discharges

“…The model predicted the behavior of dense jets with better accuracy compared to RANS models; Nevertheless, it underestimated the impact point dilution in relation to the experiments. Tofighian et al (2022) also developed a comprehensive LES study to investigate flow behavior in 15°, 30°, 45°, 60°, and 75° inclined dense jets. They focused on the near-wall region and performed several experiments with the Planar Laser-Induced Fluorescence (PLIF) techniques to verify the LES results.…”

“…Although it has shown adequate preciseness in industrial applications, it cannot predict the flow behavior in complicated geometries and problems (Zhiyin 2015). While, previous studies have demonstrated the capacity of the LES for complex geometry and realistic problems (Tofighian et al 2022). In the LES model, eddies are sorted into two classes, large and small, by utilizing the local grid sizes as a filtering criterion.…”

“…7, the instantaneous and time-averaged contours for the normalized concentration in a simple nozzle are illustrated in a diverging color map. As previously described by Tofighian et al (2022) for showing the time evolution, time could be non-dimensionalized with the ratio of initial momentum to the buoyancy fluxes (𝑀 0 𝐵 0 ⁄ ). Comparing the contours for the Venturi and simple nozzles shows significant changes in flow trajectory and jet lateral development for the Venturi discharge (Fig.…”

“…The impact point location is site-specific since it varies based on the nozzle height and bed slope. In previous studies, both return and impact points have been examined, e.g., Shao and Law (2010), Abessi and Roberts (2015), Crowe et al (2016), Ramezani et al (2021), andTofighian et al (2022). In Venturi nozzles, due to the discharge's higher elevation, flow properties (especially dilution) may be different from each other at these points.…”