Countless concerts and festivals were postponed and canceled in the early days of the coronavirus pandemic. The events took place again later, but mostly with a limited number of spectators. In order to protect both the audience and the performers from infection in the best possible way, attention was also paid to how the musicians were delivered on stage; And sometimes even changed the repertoire to use more strings than winds.

A research team from the University of Pennsylvania together with the Philadelphia Orchestra—a Pennsylvania Symphony Orchestra founded in 1900—examined how many aerosols Actually produced by wind instruments and distributed in the region. the results were In the journal “Physics of Fluids” free.

Aerosols behave like speak

The researchers used the visualization to describe the flow emanating from an orchestra’s wind instruments, such as a tuba. Then they tracked the particles with a laser. They also measured the aerosol concentration with a particle counter. These two measurements were then combined to calculate the extent to which aerosol velocity decreases with increasing distance from the instrument.

Surprising results: aerosols emitted by air devices have a similar concentration and size distribution, similar to aerosols emitted during normal speaking and breathing. Flow measurements also revealed that the speed at which aerosols exit the device is much less than the rate at which they exit when coughing or sneezing.

two meters is enough

“Ideally, musicians sit next to each other while composing and making music – this became a problem during the coronavirus pandemic,” say study authors paulo aratia, Professor in the Department of Engineering at the University of Pennsylvania. “But we were surprised that the amount of aerosol produced by air instruments is about the same as the range of normal speech.”

They had “expected much higher flow velocities and aerosol concentrations”. Aerosol distribution does not rise more than two meters – measured from the opening of the instrument. As a result, musicians playing wind instruments must keep a distance of about two meters – or as it would be called in Austria: the length of a baby elephant – on the stage.

Next, the research team wants to investigate what aerosol concentration and diffusion speed arise from the interaction of the whole orchestra. The study’s author, Aratia, hopes that in the future health authorities will include it in the requirements for the safe implementation of concerts and festivals.