Low-dissipation finite element strategy for low Mach number reacting flows

Both, Ambrus; Lehmkuhl, O.; Mira, Daniel; Ortega, Marcos

doi:10.1016/j.compfluid.2020.104436

Cited by 18 publications

(13 citation statements)

References 29 publications

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“…In this study an eddy-viscosity subgrid-scale model (Vreman model) ( Vreman, 2004 ) is applied. This model provided good results in previous simulations of respiratory airways ( Calmet et al, 2020 ) or jets ( Both, Lehmkuhl, Mira, & Ortega, 2020 ) being competitive comparing with more computational demanding models like the dynamic Smagorinsky, see Koullapis et al (2017) .…”

Section: Governing Equationsmentioning

confidence: 73%

Computational modelling of an aerosol extraction device for use in COVID-19 surgical tracheotomy

Calmet

Bertomeu

McIntyre

et al. 2022

Journal of Aerosol Science

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In view of the ongoing COVID-19 pandemic and its effects on global health, understanding and accurately modelling the propagation of human biological aerosols has become crucial. Worldwide, health professionals have been one of the most affected demographics, representing approximately 20% of all cases in Spain, 10% in Italy and 4% in China and US. Methods to contain and remove potentially infected aerosols during Aerosol Generating Procedures (AGPs) near source offer advantages in reducing the contamination of protective clothing and the surrounding theatre equipment and space. In this work we describe the application of computational fluid dynamics in assessing the performance of a prototype extraction hood as a means to contain a high speed aerosol jet. Whilst the particular prototype device is intended to be used during tracheotomies, which are increasingly common in the wake of COVID-19, the underlying physics can be adapted to design similar machines for other AGPs. Computational modelling aspect of this study was largely carried out by Barcelona Supercomputing Center using the high performance computational mechanics code Alya. Based on the high fidelity LES coupled with Lagrangian frameworks the results demonstrate high containment efficiency of generated particles is feasible with achievable air extraction rates.

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Section: Governing Equationsmentioning

confidence: 73%

Computational modelling of an aerosol extraction device for use in COVID-19 surgical tracheotomy

Calmet

Bertomeu

McIntyre

et al. 2022

Journal of Aerosol Science

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“…The eddy-viscosity is obtained from the Vreman [43] model using a constant c k = 0.1. The same single-value constant has been used in previous studies and it is also retained here [3,25].…”

Section: Gas Phase 221 Governing Equationsmentioning

confidence: 99%

Analysis of local extinction of a n-heptane spray flame using large-eddy simulation with tabulated chemistry

Benajes

García-Oliver

Pastor

et al. 2022

Combustion and Flame

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“…The LES filtered governing equations in the Eulerian solver include the continuity, momentum, enthalpy, and mass fraction of water in the gas phase for the low-Mach number limit. 41 The latter is used to track the mixing fields between evaporated droplets and air. The system of equations is given by

…”

Section: Boundary Conditionsmentioning

confidence: 99%

Large eddy simulation of cough jet dynamics, droplet transport, and inhalability over a ten minute exposure

et al. 2021

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High fidelity simulations of expiratory events such as coughing provide the opportunity to predict the fate of the droplets from the turbulent jet cloud produced from a cough. It is well established that droplets carrying infectious pathogens with diameters of remain suspended in the air for several hours and transported by the air currents over considerable distances (e.g., in meters). This study used a highly resolved mesh to capture the multiphase turbulent buoyant cloud with suspended droplets produced by a cough. The cough droplets' dispersion was subjected to thermal gradients and evaporation and allowed to disperse between two humans standing 2 m apart. A nasal cavity anatomy was included inside the second human to determine the inhaled droplets. Three diameter ranges characterized the droplet cloud, , which made up 93% of all droplets by number; 5 to 100 μ m comprised 3%, and m comprising 4%. The results demonstrated the temporal evolution of the cough event, where a jet is first formed, followed by a thermally driven puff cloud with the latter primarily composed of droplets under 5 μ m diameter, moving with a vortex string structure. After the initial cough, the data were interpolated onto a more coarse mesh to allow the simulation to cover ten minutes, equivalent to 150 breathing cycles. We observe that the critical diameter size susceptible to inhalation was , although most inhaled droplets after 10 min by the second human were approximately . These observations offer insight into the risk of airborne transmission and numerical metrics for modeling and risk assessment.

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Low-dissipation finite element strategy for low Mach number reacting flows

Cited by 18 publications

References 29 publications

Computational modelling of an aerosol extraction device for use in COVID-19 surgical tracheotomy

Computational modelling of an aerosol extraction device for use in COVID-19 surgical tracheotomy

Analysis of local extinction of a n-heptane spray flame using large-eddy simulation with tabulated chemistry

Large eddy simulation of cough jet dynamics, droplet transport, and inhalability over a ten minute exposure

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