Open Access

ARTICLE

Influences of the Fresh Air Volume on the Removal of Cough-Released Droplets in a Passenger Car of a High-Speed Train Using CFD

by Jun Xu¹, Kai Bi¹, Yibin Lu^2,*, Tiantian Wang^2,3, Hang Zhang², Zeyuan Zheng³, Fushan Shi³, Yaxin Zheng³, Xiaoying Li², Jingping Yang³

1 CRRC Changchun Railway Vehicles Co., Ltd., Changchun, 130062, China
2 Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha, 410075, China
3 College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China

* Corresponding Author: Yibin Lu. Email:

(This article belongs to the Special Issue: Computer Modeling in Vehicle Aerodynamics)

Computer Modeling in Engineering & Sciences 2024, 138(3), 2727-2748. https://doi.org/10.32604/cmes.2023.031341

Received 05 June 2023; Accepted 01 August 2023; Issue published 15 December 2023

Abstract

The spread and removal of pollution sources, namely, cough-released droplets in three different areas (front, middle, and rear areas) of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics (CFD) method. In addition, the structure of indoor flow fields was also analysed. The results show that the large eddies are more stable and flow faster in the air supply under Mode 2 (fresh air volume: 2200 m³/h) compared to Mode 1 (fresh air volume: 1100 m³/h). By analysing the spreading process of droplets sprayed at different locations in the passenger car and with different particle sizes, the removal trends for droplets are found to be similar under the two air supply modes. However, when increasing the fresh air flow volume, the droplets in the middle and front areas of the passenger car are removed faster. When the droplets had dispersed for 60 s, Mode 2 exhibited a removal rate approximately 1%–3% higher than Mode 1 for small and medium-sized droplets with diameters of 10 and 50 μm. While those in the rear area, the situation is reversed, with Mode 1 slightly surpassing Mode 2 by 1%–3%. For large droplets with a diameter of 100 μm, both modes achieved a removal rate of over 96% in all three regions at the 60 s. The results can provide guidance for air supply modes of passenger cars of high-speed trains, thus suppressing the spread of virus-carrying droplets and reducing the risk of viral infection among passengers.

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