The central component of the facility is the segmented arc heater, which heats the working gas to total temperatures between 4000 and 7000 K. This high thermal energy is almost fully converted into kinetic energy in the downstream nozzle so that the gas in the test chamber reaches speeds of several kilometers per second.
Together with its „little brother“ L2K, L3K plays a key role for the characterisation of heat shield componen¬ts and the qualification of hot structures for spacecraft in Europe.
In the L3K test section, stagnation point models with a diameter of up to 100 mm can be tested at cold wall heat flux to 4 MW/m2 and Pitot pressures up to 350 hPa. Under these test conditions surface temperatures of up to 2600°C can be achieved. The model size in the plate configuration is 270 mm (wide) x 330 mm (long) and 55 mm (high).
The L3K is also used for the investigation of the impact of high temperature effects on the gas-surface-interaction. With the spectroscopic test methods established at the L3K, such as laser induced fluorescence (LIF), emission spectroscopy and infrared thermography both gas parameters and surface temperatures can be captured simultaneously.
Local aerothermodynamic problems arising from thermal protection concepts often cannot be simulated satisfactorily with numeric methods and need to be investigated experimentally. For the SHEFEX flight experiment the effectiveness of seals between adjoining thermal protection panels was tested systematically in the L3K.
Apart from material characterisation and hot structure qualification, flight sensors for entry and hypersonic flights are also tested and qualified in the L3K.