Propulsion Environment like Testing of Radiative- and Active Cooled Ceramic Matrix Composites by using the 'ERBURIG~K'* Test facility *Environmental Relevant Burner Rig Kerosene

摘要

Typical environments in combustion chambers are quite complex. Such atmospheres cover high gas temperatures, high gas velocities and fluctuations of gas composition due to inhomogeneous mixing or turbulences during combustion. Additionally the gas composition itself varies with the type of propellant used for the rocket engine. Therefore challenging requirements on materials for propulsion devices are their ability to withstand high thermo-mechanical as well as thermo-chemical loads during operation. A demanding task is the potential increase of combustion efficiency resulting in higher material temperatures (up to ~1900°C) which has to be verified in the harsh propulsion environment. From this the field of potential materials for suchlike propulsion devices is very limited but amongst others (e.g. noble- or refractory metallic alloys) active- as well as pure radiative-cooled ceramic-matrix-composites (CMCs) are possible candidates for such applications. Testing of combustion devices, with the baseline task of material investigation and evaluation, is a time- and effort-consuming and therefore an expensive business, while pure thermo-gravimetric analyses are much cheaper but neglect some important significances/determining factors like gas velocity and sample geometry. To keep development costs at a minimum, it is of ultimate importance to have a fast, reliable, customizable and cost-efficient way of material testing and screening. The recent established Environmental Relevant Burner Rig (ERBURIG) covers a fast material as well as small component (e.g. micro-combustion-chambers) screening with the investigation-potential of cooled and uncooled material and component behavior in combustion-like environments. During ERBURIG-testing the typical influence factors on combustion components (temperature, pressure, hot gas velocity and chemistry) can be verified and so investigated. Amongst this, the potential influence of different cooling mechanisms based on air, water, propellant, etc. can be studied and determined. Therefore the high priced and complex high temperature full-scale- or sub-scale-motor-testing can be limited to a minimum. Materials can be tested on flat specimen as well as on component level in a wide temperature range, in oxidizing and reducing atmospheres as well as in extreme gas velocities to assess their suitability for combustion relevant environments.The ERBURIG test facility exists in two different versions, one version (ERBURIG~K) used for carbon-based rocket propellants, using kerosene and oxygen as combustibles, and one version (ERBURIG~H) using hydrogen and oxygen as combustibles to create atmospheres typical for rocket engines like Ariane 5 main thruster VULCAIN Ⅱ or Space Shuttle Main Engine. Currently different radiative cooled as well as actively cooled CMC substrates like C/C, C/C-SiC, C/SiC as well as several oxide based CMCs manufactured via different production processes were investigated and evaluated in a temperature range between 1300°C and 2050°C and relevant operational environment. The materials were partially armed with Ultra-High-Temperature Coatings (UHTC's like CVD-P-SiC, CVD-HfC + CVD-p-SiC and CVD-p-SiC + plasma sprayed ZrB_2-SiC multilayer-coatings), but also uncoated/bare CMCs were exposed to the hot gas jet. Furthermore first components in micro-combustion-chamber geometries were tested in cooled and uncooled layout.