Turbulent structures of buoyant jet in cross-flow studied through large-eddy simulation

Cintolesi, Carlo; Petronio, Andrea; Armenio, Vincenzo

doi:10.1007/s10652-018-9629-1

Cited by 22 publications

(15 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assumption has been proven to be effective in the simulation of natural convection processes [55,56].…”

Section: Large-eddy Simulation Techniquementioning

confidence: 99%

“…In addition, the value of ν SGS is compared with the molecular kinematic viscosity ν, by scrutinising the ratio γ = ν/(ν + ν SGS ). Such parameter measures the contribution of the sub-grid scale with respect to the computational mesh used: γ ∼ 1 indicates that the LES reduces to a quasi DNS, γ ∼ 0 means a high contribution of turbulent model and thus a coarse spatial resolution, while γ > 1/3 corresponds to ν/ν SGS = 2 and suggests a good mesh resolution [55,64]. In the region above the slope where the largest part of the anabatic flow is localised, γ > 0.75 indicating that the correction due to the turbulent model is limited and that the turbulent kinetic energy is dissipated mainly by the resolved scale of motion than the sub-grid scales.…”

Section: Computational Grid Initial and Boundary Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Anabatic Flow along a Uniformly Heated Slope Studied through Large-Eddy Simulation

et al. 2021

Self Cite

View full text Add to dashboard Cite

Anabatic flows are common phenomena in the presence of sloping terrains, which significantly affect the dynamics and the exchange of mass and momentum in the low-atmosphere. Despite this, very few studies in the literature have tackled this topic. The present contribution addresses this gap by utilising high-resolved large-eddy simulations for investigating an anabatic flow in a simplified configuration, commonly used in laboratory experiments. The purpose is to analyse the complex thermo-fluid dynamics and the turbulent structures arising from the anabatic flow near the slope. In such a flow, three main dynamic layers are identified and reported: the conductive layer close to the surface, the convective layer where the most energetic motion develops, and the outer region, which is almost unperturbed. The analysis of instantaneous fields reveals the presence of thermal plumes, which are stable turbulent structures enhancing vertical transport and mixing of momentum and temperature. Such structures are generated by thermal instabilities in the conductive layer that trigger the rise of the plumes above them. Their evolution along the slope is described, identifying three regions responsible for the plumes generation, stabilisation, and merging. To the best of the authors’ knowledge, this is the first numerical experiment describing the along-slope behaviour of the thermal plumes in the convective layer.

show abstract

“…This assumption has been proven to be effective in the simulation of natural convection processes [55,56].…”

Section: Large-eddy Simulation Techniquementioning

confidence: 99%

Section: Computational Grid Initial and Boundary Conditionsmentioning

confidence: 99%

Anabatic Flow along a Uniformly Heated Slope Studied through Large-Eddy Simulation

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The pimpleFoam basic code was customized to also solve pollutant concentration equations, while the dynamic Lagrangian model was implemented ex novo. Such a turbulent model has been previously tested and validated (Cintolesi et al 2019).…”

Section: Numerical Set-upmentioning

confidence: 99%

Large-Eddy Simulations of Pollutant Removal Enhancement from Urban Canyons

Cintolesi

Pulvirenti

Sabatino

2021

Boundary-Layer Meteorol

Self Cite

View full text Add to dashboard Cite

Techniques for improving the removal of pollution from urban canyons are crucial for air quality control in cities. The removal mainly occurs at the building roof level, where it is supported by turbulent mixing and hampered by roof shear, which tends to isolate the internal canyon region from the atmospheric flow. Here, a modification of roof infrastructures is proposed with the aim of increasing the former and reducing the latter, overall enhancing the removal mechanisms. The topic is investigated by numerical experiment, using large-eddy simulation to study the paradigmatic case of a periodic square urban canyon at $$ Re=2 \times 10^4$$ R e = 2 × 10 4 . Two geometries are analyzed: one with a smooth building roof, the other having a series of solid obstacles atop the upwind building roof. The pollutant is released at the street level. The simulations are successfully validated against laboratory and numerical datasets, and the primary vortex displacement detected in some laboratory experiments is discussed. The turbulence triggered by the obstacles destroys the sharp shear layer that separates the canyon and the surrounding flow, increasing the mixing. Greater vertical turbulent mass fluxes and more frequent ejection events near the upwind building (where pollution accumulates) are detected. Overall, the obstacles lead to a reduction in the pollution concentration within the canyon of about $$34\%$$ 34 % .

show abstract

“…Cintolesi et al [26] performed LES simulations of buoyant jets in a neutral crossflow. Their simulations reproduced the counter-rotating vortex pair in the entrainment region where crossflow dominates over the initial momentum and buoyancy.…”

Section: Plume Bifurcationmentioning

confidence: 99%

Cooling tower plume abatement and plume modeling: a review

Flynn

2021

Environ Fluid Mech

View full text Add to dashboard Cite

Visible plumes above wet cooling towers are of great concern due to the associated aesthetic and environmental impacts. The parallel path wet/dry cooling tower is one of the most commonly used approaches for plume abatement, however, the associated capital cost is usually high due to the addition of the dry coils. Recently, passive technologies, which make use of free solar energy or the latent heat of the hot, moist air rising through the cooling tower fill, have been proposed to minimize or abate the visible plume and/or conserve water. In this review, we contrast established versus novel technologies and give a perspective on the relative merits and demerits of each. Of course, no assessment of the severity of a visible plume can be made without first understanding its atmospheric trajectory. To this end, numerous attempts, being either theoretical or numerical or experimental, have been proposed to predict plume behavior in atmospheres that are either uniform versus density-stratified or still versus windy (whether highly-turbulent or not). Problems of particular interests are plume rise/deflection, condensation and drift deposition, the latter consideration being a concern of public health due to the possible transport and spread of Legionella bacteria.

show abstract

Turbulent structures of buoyant jet in cross-flow studied through large-eddy simulation

Cited by 22 publications

References 38 publications

Anabatic Flow along a Uniformly Heated Slope Studied through Large-Eddy Simulation

Anabatic Flow along a Uniformly Heated Slope Studied through Large-Eddy Simulation

Large-Eddy Simulations of Pollutant Removal Enhancement from Urban Canyons

Cooling tower plume abatement and plume modeling: a review

Contact Info

Product

Resources

About