Technological Aspects of Transpiration Cooled Composite Structures for Thrust Chamber Applications

The long-term development of transpiration cooled ceramic rocket thrust chambers at the German Aerospace Center (DLR) currently culminates in designs of self-sustaining fibre reinforced rocket engine chamber structures. This paper explains characteristic issues and potential benefits introduced by this new technology, which seem to be achievable in terms of weight and cost reduction, increased reliability and higher lifetime due to no longer existing thermal cycling sensitivity. The paper furthermore describes design and functional aspects of the chamber, the component manufacturing process and shows some experimental results of test campaigns with respect to structure and material relevance. DLR’s development road map is sketched and the technology readiness level achieved so far is discussed. Nomenclature ISP = specific impulse kd = coefficient of Darcyan permeability kf = coefficient of non-Darcyan (Forchheimer) permeability L = flow length pin = inflow pressure pout = outflow pressure T = temperature v = velocity Δp = pressure loss λ = thermal conductivity (CTC) e = porosity η = dynamic viscosity ρ = density