Vehicle Climate Control Systems

One of the most impressive features of Fraunhofer IBP's Holzkirchen site is its unique flight test facility. This comprises a low-pressure chamber housing the front section of an Airbus A310-200, which is approximately 15 meters long with space for up to 80 test subjects. This test facility enables EER researchers to study various parameters that influence cabin air quality by simulating in-flight conditions. The researchers also conduct studies of the aircraft as an overall system by investigating the energy aspects and usage requirements of areas such as the cockpit, passenger cabin, avionics and cargo bay. The team also studies thermodynamic correlations and the build-up of condensation on aircraft components, both within international projects and on behalf of manufacturers and suppliers from the aviation industry.

In the scope of the Clean Sky Joint Undertaking (European Aeronautics Research Project) IBP's flight test facilities could be extended by adding a business jet platform. Thanks to this platform it is now possible to safely perform complex on-board tests simulating in-flight and ground situations alike. Available test conditions consider the extreme temperatures and the air pressure that can occur inside an aircraft cabin during flights or on the ground. For this purpose, three demonstrators were integrated in IBP's flight test facilities: a carbon cockpit mock-up, a cabin segment and a rear segment of the airplane including baggage and instrument compartments. These test facilities were completed by the Aircraft Calorimeter (ACC), which can additionally expose a variable test space to a thermal shock (extremely rapid cooling) and rapid pressure loss.

In the last few years, this set-up was mainly used for testing heat pipes for aircraft cooling, and for validating the thermal models that were created using the 'Thermal Model Generation Tool'. The thermal models generated in this way are distinguished by an extremely high speed of calculation compared to conventional CFD calculations. The low spatial resolution achieved in this process is much more appropriate for simulating internal spaces, as high-resolution but time-consuming CFD simulations of interior spaces are representative only to a limited extent; besides, they can hardly be validated for this area of application.