Injector-Head Pre-Designs Adjusted to Innovative Ceramic Rocket Thrust Chambers
- Paper number
IAC-20,C4,IP,18,x59393
- Author
Mr. Markus Ortelt, Germany, German Aerospace Center (DLR)
- Year
2020
- Abstract
DLR’s Black Engine technology is currently going to market transfer. The first challenging goal is the rocket engine development on 60 kN thrust level for flexible competitive New Space applications. Related to the expectation of comparably low cost, low weight and highly reliable long-life engines an ISP (vac) of 330 sec represents the efficiency bench mark. Promising transpiration cooled CMC (Ceramic Matrix Composites) rocket thrust chamber designs require corresponding injector function adjusted to the interaction of wall blow rate, mixing and combustion. As a reaction to the observed interaction effects in several previous high performance cryogenic (LOX/LH2) test campaigns, the preferred (cryogenic) fuel inflow through the porous CMC wall works the safest by generating injector spray as fine as possible coming from the face-plate. Driven by this requirement new injector head layouts have been pre-designed. Close to application the new thrust chambers target the use of LOX and LNG. Caused by more difficult mixing and ignition compared to LOX/LH2 operation, DLR intends on the one hand, in combination with a classical cylindrical combustion chamber geometry, the change from co-axial shear injection to tri-co-axial swirl patterns, in which the generation of a multiplicity of fine propellant jets shall be applied, enabled preferably by AM manufacturing. Here the adjustment to classical J-Numbers in the range of 2 3 should be preserved. On the other hand DLR’s new ‘cone injector’ head, targeting the new injection cooling method in combination with the innovative dual-shell-hyperboloid combustion chamber technology, the application of free jet diffusion flame combustion is in the foreground. In this case again fine LOX jet patterns, coming from the face-plate, will be injected into an established plenum of fuel, significantly supported by an extraordinary fuel inflow through two separated and nested porous combustion chamber wall sections. At least 30 % fuel injection through the wall components represents the motivating goal of extremely safe operation under highly efficient combustion conditions.
- Abstract document
- Manuscript document
(absent)