Structure of turbulent separated flow in the neighborhood of a plate-mounted prism of square section

Comparison of RANS and scale-resolving approaches when modelling the turbulent flow behind a bluff body

“…In figures, symbols stand for experimental results. Lines 1-3 present the results of previous computations [5] with the standard k-ɛ (1), k-ω (2) turbulence models and the k-ω model with the Kato-Launder limiter ( As it can be seen in figures, DES turbulence model gives better results than results of [5] for the mean velocity profile at both sections and TKE profile at the X1 section. The classical k-ε and k-ω turbulence models yield several times overestimated turbulence levels in the separation zone before the prism.…”

“…In this paper, the calculations of the flow in the vicinity of a parallelepiped fixed on a plate are performed under the condition of the experiment [4]. Earlier, the authors calculated the same flow using various RANS-based turbulence models [5]. The vortex structure of the flow was studied.…”

Estimation of pollutant dispersion around a building within non-isothermal boundary-layer using detached eddy simulation

“…From the point of view of pollutant gas dispersion is the vortex zone -1, behind the prism, where the tracer gas injected from the ground, represents the biggest interest. The study [22] described the isothermal case of a flow around a prism with a size ratio 2:1:1 fixed on a flat plate and found that the RANS approach underestimates the TKE level in zone -1, which leads to a significant overestimation of the longitudinal size of the separation zone behind the prism. In addition, application of this approach to assess pollutant dispersion around buildings is often difficult in terms of choosing semi-empirical constants of the turbulence model [34,35].…”

“…For instance, meta-analysis of the existing data [15,19] demonstrate that the LES/DES approaches are more rarely applied to urban aerodynamics tasks with consideration for microclimatic processes if we compare them with the common RANS/URANS semi-empirical models. At the same time, RANS/URANS approaches do not allow us to calculate turbulent flow characteristics in a correct manner, for instance, when applied to predicting the size of boundarylayer separation zones and recirculation zones that appear in flows around buildings and street canyons [20][21][22].…”

Mathematical Modelling of City Aerodynamics

“…In [17], the authors carried out the numerical simulation of turbulent flows of incompressible air in the vicinity of a plate-mounted prism of a square cross-section. The comparison with experimental data [18] on the velocity and turbulent kinetic energy (TKE) profiles was performed and satisfactory agreement was obtained.…”