Numerical investigation of the swirling air diffuser: Parametric study and optimization

Large eddy simulation of turbulent flow and mass transfer in far-field of swirl diffusers

“…9, the first Coanda jet at ˛ = 55 • is more effective in mixing the fresh air, in comparison with other simulated jets. The complement of this swirl angle is 35 • (lead angle) that is in agreement with the efficient blade angle of 32 • reported by Sajadi et al (k-ε simulation) [2]. The small difference between these angles is mainly because of the differences in methods and diffusers' types.…”

“…Several methods and indexes are proposed in the available literature to measure the effectiveness of this process. Some definitions such as the jet decay coefficient and entrainment ratio [1,2] are based on the near-field geometry and convective properties of the jet. Nevertheless, the turbulent and molecular diffusions are also important in the far-field mixing.…”

“…Sajadi et al also performed numerical simulations to optimize the blade angle of swirl diffusers [2]. Both of these works are based on steady-state Reynolds-average Navier-Stokes equations with the k-ε model in simulations.…”

“…Swirl is usually added to the flow by means of guide vanes at the diffuser outlet [1,2], but it can also be a side effect of the flow generator mechanism. For example, the rotating blades of a ceiling fan induce swirl to the main flow stream [3].…”

Experimental analysis of mixing ventilation efficiency using a vortex diffuser: Comparison to a lobed multicone diffuser

“…The experimental studies in references [11,12] were cited or were used as a reference data in a number of numerical studies [18][19][20] dealing with CFD simulation of jets from ceiling vortex diffusers. The most recent numerical study [20] focuses on the effect of the angle between the impellers and the vertical axis, on the jet behavior and on the resulting air quality in the room (qualified by the predicted total age of the air [21,22]).…”