Zonal model validation for an environmentally friendly aircraft cargo fire protection system with containerized load

Today’s cargo bays use halon as fire suppression agent. However, due to the high ozone depletion potential of this chemical, alternative solution are researched. Within this framework, the cargo bay in the Fraunhofer Flight Test Facility has been equipped with a nitrogen based fire suppression system to investigate the local distribution of oxygen and nitrogen concentrations. This paper focusses on the system performance when empty or loaded with geometrically equivalent LD3 container elements that replicate the flow blockage for the fire suppression agents in the cargo hold. Furthermore, the test data is used to validate a zonal model predicting the local distribution of agents in the cargo hold. This simulation tool has been developed within the CleanSky2 Environmentally Friendly Aircraft Cargo Fire Protection System.