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Article
Publication date: 11 January 2022

Hamid Reza Tamaddon Jahromi, Igor Sazonov, Jason Jones, Alberto Coccarelli, Samuel Rolland, Neeraj Kavan Chakshu, Hywel Thomas and Perumal Nithiarasu

The purpose of this paper is to devise a tool based on computational fluid dynamics (CFD) and machine learning (ML), for the assessment of potential airborne microbial…

186

Abstract

Purpose

The purpose of this paper is to devise a tool based on computational fluid dynamics (CFD) and machine learning (ML), for the assessment of potential airborne microbial transmission in enclosed spaces. A gated recurrent units neural network (GRU-NN) is presented to learn and predict the behaviour of droplets expelled through breaths via particle tracking data sets.

Design/methodology/approach

A computational methodology is used for investigating how infectious particles that originated in one location are transported by air and spread throughout a room. High-fidelity prediction of indoor airflow is obtained by means of an in-house parallel CFD solver, which uses a one equation Spalart–Allmaras turbulence model. Several flow scenarios are considered by varying different ventilation conditions and source locations. The CFD model is used for computing the trajectories of the particles emitted by human breath. The numerical results are used for the ML training.

Findings

In this work, it is shown that the developed ML model, based on the GRU-NN, can accurately predict the airborne particle movement across an indoor environment for different vent operation conditions and source locations. The numerical results in this paper prove that the presented methodology is able to provide accurate predictions of the time evolution of particle distribution at different locations of the enclosed space.

Originality/value

This study paves the way for the development of efficient and reliable tools for predicting virus airborne movement under different ventilation conditions and different human positions within an indoor environment, potentially leading to the new design. A parametric study is carried out to evaluate the impact of system settings on time variation particles emitted by human breath within the space considered.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 19 May 2021

HamidReza Tamaddon Jahromi, Samuel Rolland, Jason Jones, Alberto Coccarelli, Igor Sazonov, Chris Kershaw, Chedly Tizaoui, Peter Holliman, David Worsley, Hywel Thomas and Perumal Nithiarasu

A novel modelling approach is proposed to study ozone distribution and destruction in indoor spaces. The level of ozone gas concentration in the air, confined within an indoor…

161

Abstract

Purpose

A novel modelling approach is proposed to study ozone distribution and destruction in indoor spaces. The level of ozone gas concentration in the air, confined within an indoor space during an ozone-based disinfection process, is analysed. The purpose of this work is to investigate how ozone is distributed in time within an enclosed space.

Design/methodology/approach

A computational methodology for predicting the space- and time-dependent ozone concentration within the room across the consecutive steps of the disinfection process (generation, dwelling and destruction modes) is proposed. The emission and removal of ozone from the air volume are possible by means of a generator located in the middle of the room. This model also accounts for ozone reactions and decay kinetics, and gravity effect on the air.

Finding

This work is validated against experimental measurements at different locations in the room during the disinfection cycle. The numerical results are in good agreement with the experimental data. This comparison proves that the presented methodology is able to provide accurate predictions of the time evolution of ozone concentration at different locations of the enclosed space.

Originality/value

This study introduces a novel computational methodology describing solute transport by turbulent flow for predicting the level of ozone concentration within a closed room during a COVID-19 disinfection process. A parametric study is carried out to evaluate the impact of system settings on the time variation of ozone concentration within the space considered.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 1 November 2011

Rhodri Bevan, P. Nithiarasu, Igor Sazonov, Raoul van Loon, Heyman Luckraz, Michael Collins and Andrew Garnham

The purpose of this paper is to numerically study blood flow through a subject‐specific carotid artery with a moderately severe stenosis, also to thoroughly analyse the wall shear…

261

Abstract

Purpose

The purpose of this paper is to numerically study blood flow through a subject‐specific carotid artery with a moderately severe stenosis, also to thoroughly analyse the wall shear stress (WSS), oscillatory shear index (OSI) and WSS angular deviation (WSSAD). One of the important aspects of this study is the investigation on the influence of the extensions attached to the domain outlets.

Design/methodology/approach

The segmentation of the carotid artery is carried out using a deformable model based on a level set method. A geometric potential force (GPF) is employed to deform the level set to obtain the carotid artery geometry. The initial surface meshing is generated using an advanced marching cubes (MC) method, before improving the quality of the surface mesh via a number of mesh cosmetic steps. The volume mesh generation has two parts. In the first part, a quasi‐structured, boundary layer mesh is generated in the vicinity of the geometry walls. The second part of the meshing involves unstructured tetrahedral meshing of the inner part of the geometry. After the meshing stage, the flow boundary conditions are generated by numerically solving the Helmholtz equation in both space and time. Finally, the explicit characteristic‐based split (CBS) method is employed in a parallel environment to produce a detailed analysis of wall quantities.

Findings

In general, WSS is very high in the vicinity of the carotid artery apex and in the proximity of the stenosis. From the results obtained, it is clear that the influence of outlet domain extension is marginal. While the peak instantaneous WSS differs by a maximum of 5.7 per cent, the time‐averaged WSS difference due to extended domain is only 1.3 per cent. Two other derived parameters are also examined in the paper, the oscillating shear index and the WSSAD. Both these quantities also display minor or negligible differences due to domain extension.

Originality/value

It has been perceived that domain extension is essential to avoid wrong application of boundary conditions. The results obtained, however, conclusively show that the outlet domain extension has only a moderate influence on WSS. Thus, outlet extension to the domains may not be essential for arterial blood flows. It is also observed that the dramatic values of peak WSS obtained near the stenosis is the result of high resolution mesh along with boundary layers used in this study. Both the outcomes represent the originality of this paper.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 21 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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Book part
Publication date: 29 October 2018

Svetlana V. Lobova, Igor A. Prodchenko, Tatiana M. Rogulenko, Svetlana V. Ponomareva and Victor V. Gorlov

The purpose of this chapter is to determine the basic institutes of well-balanced information economy and compile its institutional model.

Abstract

Purpose

The purpose of this chapter is to determine the basic institutes of well-balanced information economy and compile its institutional model.

Approach

The research methodology is based on the methods of the new institutional economic theory. The authors determine the most important qualitative characteristics of the innovational model of a well-balanced information economy and select social institutes that allow taking them into account and ensuring them during practical implementation of the model. The authors describe social institutes that are the basis of a well-balanced information economy and the process of their formation. The authors also use the method of modeling socio-economic phenomena and processes to compile the institutional model of a well-balanced information economy and the method of formalization of its graphic interpretation.

Findings

It is concluded that the basic institutes of the innovational model of a well-balanced information economy include the institutes of feedback collection and control and protection of information. These institutes ensure observation of the principles of implementation of this model and ensure its cyclic development and sustainability in the long-term.

Originality/Value

The presented institutional model of a well-balanced information economy harmonizes the interaction between all the participants of socio-economic relations and processes of information economy, including its state regulation, transition of new information into the category of existing (from product into resource), internal and external exchange of information, its usage, etc.

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Article
Publication date: 1 October 1988

Ernest Raiklin and Ken McCormick

The year 1988 marks a special anniversary for Russia. Exactly 1,000 years ago Christianity was officially introduced into Russia from Byzantium. This was accomplished when, in…

152

Abstract

The year 1988 marks a special anniversary for Russia. Exactly 1,000 years ago Christianity was officially introduced into Russia from Byzantium. This was accomplished when, in 988, Prince Vladimir of Kiev ordered a mass baptism of the Russian people

Details

International Journal of Social Economics, vol. 15 no. 10
Type: Research Article
ISSN: 0306-8293

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