The DRL examines the physical distribution of droplets contaminated with
viruses in trains and airplanes. The study thus provides the basis for
further research, but does not provide any information about the contagion
risk of mass mobility.
according to a study by the National Institutes of Health (NIH), can release
up to 100,000 tiny liquid droplets with the new corona virus (SARS-COV-2) into
the air , which remain there for up to 14 minutes. However , the study did not
investigate the influence of different temperatures and air movements on the
aerosol particles by an air conditioning system or a ventilation system.
Experiments by the German Aerospace Center (DLR), which will investigate how
virus particles are distributed in airplanes and trains , could soon provide
answers to these open questions . In this way, the scientists at DLR want to
develop solutions for mobility during the corona pandemic and investigate
whether mass mobility, as assumed, actually promotes the spread of the
corona virus.
Institute of Aerodynamics and Flow Technology:
The study is being carried out by scientists from the Göttingen DLR
Institute of Aerodynamics and Flow Technology, which has been one of the
world's leading research centers in the field of cabin air conditioning for
aircraft and trains for years.
According to Prof. Andreas Dillmann, director of the institute, "the focus
has so far been on passenger comfort and energy consumption for air
conditioning." As Dillmann explains, "we can now use the scientific tools we
have developed to research the spread of viruses in passenger cabins."
Open-plan compartment of a full train:
In the first part of the study, the researchers simulate a Covid-19-infected
passenger who is in the open-plan compartment of a full train with six rows
of seats. The computer simulation calculates the exhalation and possible
cough to determine the distribution of viruses. A simulation of the cabin
air flow is used, which the DLR had already created for other research
purposes. The simulation also includes aerosol particles that atomize and
evaporate in the air. According to the scientists, this process, in which
strong shear forces cause the droplets to disintegrate, is comparable to the
fuel injection in the engine.
The parameters of the different scenarios were taken from studies by the US
Federal Aviation Authority (FAA). Lung volumes between 1 and 1.5 liters and
particle sizes between one and a few hundred micrometers are thus
considered, which the simulation uses to calculate the distribution and
range.
Train laboratory with 24 dummies:
In addition, the scientists simulate a similar scenario in an experiment in
the generic train laboratory in Göttingen, for which 24 dolls with measuring
devices were distributed as passenger dummies. The distribution is tested
using a dummy that emits air with added droplets and a trace gas into its
surroundings. The recording is carried out by both gas sensors and
high-speed cameras, which document the distribution in the cabin air. In
addition, a number of sensors record the particles and their concentration
at different positions in the compartment.
Aircraft cabins are closed systems:
Another computer simulation also examines the distribution of particles in
aircraft. As part of the EU project ADVENT, an experiment will soon follow
in a new aircraft laboratory in Göttingen.
Prof. Rolf Henke, Director of Aviation at DLR: “Aircraft cabins are
self-contained systems and already have a high level of air pollution
control. Our research into the spread of viruses in cabins should help
protect passengers from infections and find answers to the question: How can
flying be safe in the future? ”
No statement about the risk of infection:
The scientists note that their study will only provide information about the
physical distribution of droplets contaminated with viruses. However, the
study cannot answer how high the infectivity of these droplets and thus the
risk of infection in trains and planes is. The possible influence of air
filters, which are usually used in airplanes, cannot be determined from the
study data.
According to the DLR researchers from Göttingen, the first results will
follow in the coming weeks. However, according to the DRL, the
implementation and evaluation of some experiments will take several months.
Artical reference:https://www.forschung-und-wissen.de/nachrichten/medizin/dlr-analysiert-sars-cov-2-verbreitung-in-flugzeugen-und-zuegen-13373876
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