A comparative analysis of potential aerosol exposure in a wide-body aircraft cabin using tracer gas and fluorescent particles

Abstract

We compare two aerosol surrogate tracers in aircraft cabins for breathing and coughing sources: tracer gas collected in the ACER Boeing 767 mock-up and fluorescent particles collected in an actual Boeing 767 aircraft by the US Transportation Command (TRANSCOM). Each source was located individually in window and middle seats. Exposure generally decreased with source distance. A window seat breathing source resulted in good agreement between datasets for exposure (as percent of release) for the TRANSCOM hangar-AFT testing mode, which corresponds to the 11-row cabin ACER laboratory space. Average tracer gas exposure for a middle seat breathing source was higher in the ACER study than the fluorescent particle tracer exposure in the TRANSCOM study. Using a coughing source in a window seat, the exposure for the TRANSCOM data was higher within the first two rows from the source before decreasing to and tracking with the ACER levels, until increasing after about 5 m away. A similar trend was recorded for a middle seat coughing source with higher overall exposure for the TRANSCOM data. Sources of exposure variation between the studies include particle deposition. This work helps optimize aerosol dispersion research in aircraft cabins and provides some validation to the existing studies.

Highlights

• Laboratory cabin tracer gas (ACER) and real aircraft tracer particle results (TRANSCOM) differed significantly due to deposition and chaotic airflow patterns.

• All individual seat measurements were below 0.3% of total released mass.

• Tracer gas measurements were higher than particle results for a breathing source.

• Particle results were higher than tracer gas results for a coughing source.

• Measurements showed large variability near sources and general decrease with distance.

Keywords:

• Aerosol
• aircraft
• covid-19
• tracer studies
• TRANSCOM
• ventilation

Disclosure statement

The authors have no conflicts of interest to report related to the current research.

Data availability statement

The TRANSCOM study data are publicly available at: https://figshare.com/articles/dataset/USTRANSCOM_767-Flight_Master_Spreadsheet/13093055. The ACER tracer gas data are publicly available through Seif Mahmoud’s dissertation at: https://krex.k-state.edu/handle/2097/41398. The data from every experimental trial, including those used in the current paper, appear as individual graphs in the dissertation. One reference (Grote) is a masters thesis publicly available at: https://krex.k-state.edu/handle/2097/43040.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Notes on contributors

Seif Mahmoud

Seif Mahmoud is currently a Lead Aerodynamics Engineer at GE Aerospace. He recently served as an Oak Ridge Institute (ORISE) Fellow at the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention (CDC), where he researched aerosol and pathogens dispersion in different environments. He holds a PhD degree in Mechanical Engineering from Kansas State University with interests in fluid dynamics, aerodynamics, and heat transfer.

James Bennett

James Bennett is a research engineer with the National Institute for Occupational Safety and Health (NIOSH), which is one the federal Centers for Disease Control and Prevention (CDC). He has over 30 years of experience in industrial hygiene, particularly in the design and evaluation of engineering controls, in exposure quantification, and in contaminant transport modeling. His research areas include application of CFD and spatial models to the built and industrial environments. Dr. Bennett obtained a Bachelor Degree in Electrical Engineering from the University of Michigan and a Masters and Ph.D. in Environmental Health Sciences from the University of South Carolina. He is an ASHRAE member, former Chair of the Indoor Environmental Modeling Technical Committee, TC 4.10. and the current Chair of the Technical Activities Committee (TAC).

Byron Jones

Byron Jones is Professor Emeritus at Kansas State University, Department of Mechanical and Nuclear Engineering, where he has served for 45 years. He served as technical director for the six-university National FAA Airliner Cabin Environment Research Center of Excellence. Professor Jones is a Life Member of the American Society of Mechanical Engineers and is a Fellow and Life Member of the American Society of Heating Refrigerating and Air Conditioning Engineers. He also served as a distinguished lecturer for both ASME and ASHRAE making presentations at more than 40 local chapters throughout the U.S. and in several other countries.

Mohammad Hosni

Mohammad Hosni is a Professor of Mechanical Engineering and the Director of the University Engineering Alliance at Kansas State University. He holds a Ph.D. in mechanical engineering and his research interest areas include Fluid Mechanics, Heat Transfer, Air Distribution, Human Thermal Comfort, Experimental Techniques and Uncertainty Analysis. He is a Fellow of ASME, ASHRAE, and ABET.