2026-04-13T06:22:11Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4467392026-01-22T06:10:47Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Vera i Fernández, Jordi author Schillaci, Eugenio author Amani, Ahmad author Morozova, Nina author Rigola Serrano, Joaquim author 2025-09-25 In this work, a numerical set-up is built to perform transient numerical simulations of airflow quality, contaminant transport, andrisk of infection within enclosed spaces. In particular, the case of an urban bus is proposed by studying the probability of infectionfrom SARS CoV-2 during typical urban travel. Different air supply units are analyzed: an air-conditioning device with partial outside air recirculation and an air purification system with continuous indoor air purification and different air diffuser configurations. The infection probability is evaluated using an original methodology based on the Wells–Riley model. The generation and transport of airborne infections are considered by solving a quanta transport equation that uses empiricalvalues for quanta exhalation and inhalation rates. The flow field is solved once using URANS models. Next, different target positions for infectious and target susceptible people are simulated to build a general infection probability matrix, allowing the quantification of the risk of contagion by running a set of affordable transient simulations. Air age and PM 2.5 concentration are also employed to evaluate general air quality. The numerical model, experimentally validated in past works, is verified hereusing a mesh convergence analysis. Hence, the different air supply units and configurations are analyzed with the current methodology to quantify the risk of infection, showing a 13% risk reduction when introducing the air purification unit and a 23% reduction when using the same unit but with a more efficient grid configuration. This work has been developed in the context of the RolenPurifica Bus R&D project, partially financed by INNOTEC(ACCIÓ - Agència per la Competitivitat de l’Empresa, Gen-eralitat de Catalunya). Jordi Vera has been financially sup-ported by the Ministerio de Educación y Ciencia (MEC),Spain (FPI Grant PRE2018-084017). Nina Morozova wassupported by the Ministerio de Economía y Competitividad,Spain (FPU16/06333 predoctoral contract). Peer Reviewed Postprint (published version) Àrees temàtiques de la UPC::Física::Física de fluids::Flux de fluids HVAC in public transport RANS simulation SARS-CoV-2 infection risk Wells–Riley model Numerical simulation of contaminant transport and infection probability in public transport vehicles