Characterization of new high heat flux test conditions in L3K

Abstract

During the last decades DLR’s arc heated facilities LBK had continuously been used for the characterization and qualification of ablative material. Test conditions, however, were restricted with respect to cold wall heat flux rates and stagnation pressures. With a new nozzle that was put into operation in 2009 and a new arc heater configuration improved test conditions could be achieved with flight relevant heat flux and pressure levels. In flow characterization tests maximal heat fluxes of 13.6 MW/m2 and stagnation pressures up to 917 hPa were obtained. After characterization of the flow field a test campaign was performed with ablative material samples made of AQ 61. In total, 9 cylindrical samples were tested in stagnation point configuration at three different test conditions. The samples’ surface temperature was measured by two pyrometers and erosion data, i.e. mass loss and surface recession, were evaluated. All samples survived the test in good shape without structural damage.