Model Validation for Particle Spread and Infectiveness in Aircraft Cabins

In a flight test facility twin-aisle cabin demonstrator, a test series was conducted with the objective to investigate cleaning methods for recirculated air. Based on the data, a 3D zonal airflow simulation model of particle spread and cleaning performance was validated with the aim of extrapolating results to arbitrary aircraft cabins. For the tests, particles containing a phi6 bacteriophage, a virus only attacking a specific bacterium and with a similar structure to SARS-CoV-2, was dosed through a breathing head. The particle distribution and infectiveness of the air samples were measured. State-of-the-art HEPA filtering and cleaners based on UV-C and plasma were integrated in the recirculated air path and experimentally investigated. The test results showed the best cleaning performance for the state-of-the-art HEPA filter, while the alternatives showed lower performance levels. It was noted that infectiveness and particle count did not necessarily follow a monotonic function, making the link between these two quantities challenging. Therefore, modeling showed to be able to properly replicate particle distribution in the cabin, while an assumption of infectiveness depending on particle count had to be made. The model could successfully be applied to a single-aisle aircraft cabin geometry.