Violent expiratory events: on coughing and sneezing

  title={Violent expiratory events: on coughing and sneezing},
  author={Lydia Bourouiba and {\'E}. Dehandschoewercker and John W. M. Bush},
  journal={Journal of Fluid Mechanics},
  pages={537 - 563}
Abstract Violent respiratory events such as coughs and sneezes play a key role in transferring respiratory diseases between infectious and susceptible individuals. We present the results of a combined experimental and theoretical investigation of the fluid dynamics of such violent expiratory events. Direct observation of sneezing and coughing events reveals that such flows are multiphase turbulent buoyant clouds with suspended droplets of various sizes. Our observations guide the development of… 

Multiphase large-eddy simulations of human cough jet development and expiratory droplet dispersion

Abstract Violent respiratory events play critical roles in the transmission of respiratory diseases, such as coughing and sneezing, between infectious and susceptible individuals. In this work,

Towards realistic simulations of human cough: Effect of droplet emission duration and spread angle

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  • R. DhandJie Li
  • Environmental Science
    American journal of respiratory and critical care medicine
  • 2020
Coughs and sneezes disperse a large number of droplets of varying size into the environment, and they transmit respiratory viral infections by direct or indirect physical contact, by droplets or

Direct numerical simulation of the turbulent flow generated during a violent expiratory event

The fully resolved hydrodynamics presented here can be used to inform new analytical models, leading to improved prediction of cough-induced pathogen-laden aerosol dispersion.

Transmission of airborne virus through sneezed and coughed droplets

The evolution of droplets in space and time under varying external conditions of temperature, humidity, and wind flow by using laws of statistical and fluid mechanics concludes that both temporal and geometric distance that a healthy individual should maintain from an infected one is based on the smaller droplets under flowing air, which makes the use of a mask mandatory to prevent the virus.

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

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 μm diameter, moving with a vortex string structure.

Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets

It is revealed for the first time that the breakup of the fluid into droplets continues to occur outside of the respiratory tract during violent exhalations, and the viscoelasticity of the mucosalivary fluid plays an important role in delaying fragmentation.

Transport and evaporation of virus-containing droplets exhaled by men and women in typical cough events

This work investigates the influence of the subject gender (or other physical properties providing different exhalation profiles) on both short-range and long-range airborne transmission by means of highly-resolved direct numerical simulations of the turbulent airflow and a comprehensive Lagrangian particle tracking model for the droplet motion and evaporation.

The motion of respiratory droplets produced by coughing

Coronavirus disease 2019 has become a global pandemic infectious respiratory disease with high mortality and infectiousness. This paper investigates respiratory droplet transmission, which is



A schlieren optical study of the human cough with and without wearing masks for aerosol infection control

The schlieren optical method, previously applied mostly in engineering and physics, can be effectively used here to visualize airflows around human subjects in such indoor situations, non-intrusively and without the need for either tracer gas or airborne particles.

Relation between the Airborne Diameters of Respiratory Droplets and the Diameter of the Stains left after Recovery

SEVERAL workers have investigated the numbers and sizes of droplets expelled during expiratory manoeuvres such as coughing or sneezing. When droplets are recovered by settling, by impaction or by

Flow dynamics and characterization of a cough.

The present study was designed to develop an accurate source model to define thermo-fluid boundary conditions for a cough that can aid in accurately predicting the disease transmission in various indoor environments, such as aircraft cabins, office spaces and hospitals.

Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management

Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing, and a standard human cough aerosol model was developed for Influenza Pandemic control.

Toward Understanding the Risk of Secondary Airborne Infection: Emission of Respirable Pathogens

Patients termed “superspreaders” or “dangerous disseminators” are those infrequently encountered persons with high values of cough and/or sneeze frequency, elevated pathogen concentration in respiratory fluid, and/ or increased respirable aerosol volume per expiratory event such that their pathogen emission rate is much higher than average.

The size distribution of droplets in the exhaled breath of healthy human subjects.

  • R. PapineniF. Rosenthal
  • Medicine, Environmental Science
    Journal of aerosol medicine : the official journal of the International Society for Aerosols in Medicine
  • 1997
C coughing produced the largest droplet concentrations and nose breathing the least, although considerable intersubject variability was observed, and the existence of larger sized droplets in the exhaled breath was confirmed.

The size and the duration of air-carriage of respiratory droplets and droplet-nuclei

  • J. Duguid
  • Environmental Science, Physics
    Epidemiology and Infection
  • 1946
Calculations made on the basis of the size distributions obtained in this investigation indicated that few of the smaller droplets, and thusfew of the droplet-nuclei, are likely to contain pathogenic organisms.

Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines.

Cough may be effective in individuals with mild-to-moderate degrees of respiratory muscle weakness, as only modest increases in intrathoracic pressure are needed to dynamically compress the large intrath oracic airways and increase cough flow velocity.