Black Engine Technology

Transpiration Cooled Ceramic High Performance Rocket Engines

Motivation and Design

  • Improvement of high performance rocket engines
  • Use of high temperature resistant and porous Ceramic Matrix Composites (CMC)
  • High operation efficiency combined with transpiration cooling
  • High operational reliability and damage tolerance
  • Adaptation potential focussing several propulsion system cycles
  • Light weight at high strength combined with CFRP housing
  • Low fatigue caused by low thermal expansion structures
  • Innovation potential for porous injection
  • Optimization of the supersonic nozzle interface
  • CMC/CFRP subsonic combustion chamber
  • CMC injector: new design technology
  • CMC supersonic nozzle extension.

Operational Requirements and Technological Approach

  • Optimization of the supersonic nozzle interface
  • Suitable material selections and coolant mass flow ratio‘s
  • High temperature and thermochemical resistance at inner liner
  • Natural micro-porosity of CMCs for coolant diffusion
  • Adjustable coolant-permeability at CMCs
  • Homogeneous coolant out-blow at inner surface
  • Easy structural design and manufacturing
  • Use of miscellaneous CMC properties at inner liner 
  1. Thermochemical adaptation – stacking of mixed materials
  2. Diffusion adaptation – porosity defined by production process
  3. CMC densities: 2 – 3 g/cm3
  • CFRP load shell – CTE » 6 × 10-6 1/K; densities 1.3 – 1.8 g/cm3
  • Highly de-coupled structure principle; innovative interface technologies
  • High degree of thermomechanical compatibility
  • Established material quality management and reproducibility
  • Spray optimization at porous injection
  • Multi-shell design of the supersonic CMC nozzle extension.

Technology Demonstration and Outlook

  • Thermochemical resistant CMCs damage free operated
  • High resilient CFRP-metal-interface proven & Cryogenic sealing technology reliable
  • Extensive efforts on analytical and experimental basics
  • Multiple high performance tests at
  1. European Research and Technology Test Facility P8
  2. Technology Test Bench P6.1
  • TRL (Technology Readiness Level) of transpiration cooling: 5
  • First promising P6.1 hot runs of the new injector concept
  • First P6.1 proof tests of the partial double-shell nozzle design
  • Full-scale 60 kN LOX/Methane demonstration at TRL 5
  • Industry transfer / Licencing.

German Aerospace Center (DLR)

Institute of Structures and Design

Markus Ortelt · E-Mail: ·