Concert Hall Updates Air Flow System Using 3D Modeling
The current pandemic has influenced all facets of our day-to-day lives, with leisure activities taking a particularly hard hit. As strict lockdown measures are reintroduced around the world to combat the second wave of COVID-19, movie theaters, music halls, comedy clubs and other entertainment venues are the first to be shut down. Entertainment venues, after all, are not often designed to keep people distanced, and are not usually designated essential. In the face of these restrictions, software giant Dassault Systèmes teamed up with the Philharmonie de Paristo see if they can bring orchestral performances safely back to Paris.
The Philharmonie de Paris is a huge complex built for all things music. It’s got everything from large concert halls to rehearsal spaces, and regularly runs events such as mini-festivals, historical exhibitions, workshops—and, of course, concerts, concerts, concerts. The Philharmonie’s largest concert hall, named after classical music legend Pierre Boulez, has seating to accommodate 2,400 audience members and features a concave inner architecture to enhance acoustics. The intimate setting of the Grande Salle Pierre Boulez certainly seems incompatible with the pandemic.
Dassault Systèmes studied the interior of the Grande Salle Pierre Boulez to assess the risk of viral transmission within the hall when it is occupied, and to make recommendations as to how the hall could be safely reopened. The company began this process by building a detailed 3D model of the hall’s interior—complete with its unique ventilation system that includes a dedicated vent underneath each seat.
A 3D model of the concert hall. (Image courtesy of Philharmonie de Paris.)
Using this model, Dassault Systèmes was able to simulate the general flow of air through the hall. The team found that the hall’s ventilation system, with vents at each seat, allows air to flow primarily from the back of the hall to its center with very little lateral movement. Less mixing of air is great for reduced particle dispersion; it means that air exhaled by one person will not be blown sideways into other people’s faces. This system also allows for much slower airflow than usual (less than 1 km/hr), since air is constantly getting nudged toward the center at each seat, whereas in a conventional system, large airflows are needed to drive the air from a back wall all the way to the center. That’s another win for the hall. Faster airflow would allow particles to be carried farther and faster.
Once the overall airflow in the hall was simulated, Dassault Systèmes went in for a closer look. They decided to examine the effectiveness of face masks in limiting the spread of particles between audience members. They did so by focusing their model on a small group of audience members within the fully occupied hall and examining the difference when audience members were fitted with a loose face mask, a fitted mask, or no mask at all. To no one’s surprise, their results confirmed that fitted face masks play an important part in preventing viral particle transmission.
Dassault Systèmes concluded that airflow within the hall is similar to that in an open-air environment, and that by reducing ventilation airflow to 50 percent and enforcing face mask wearing, the hall could be allowed to reopen safely. Personally, I’m not so convinced. There is no mention of reducing the hall’s capacity, and the thought of 2,400 people crowding into neighboring seats indoors makes me queasy. I find myself wondering if this study is not overly academic—what about people shifting in their seats, turning sideways to speak to the person next to them? What about viral particles carried on people hands and belongings? The Grande Salle Pierre Boulez might be the safest concert hall you can visit during the pandemic, but is itsafe ?