The scope for the development of the low NOx combustion technology should include the following steps:

• Development of a new innovative fuel injection system capable of creating a homogeneous fuel/air distribution, reliable and safe ignition, and flame stabilisation without autoignition and flash-back, no overheating of flame holding and combustor structures, and effective control of the NOx production across typical aero engine operating ranges;
• Demonstration of the low NOx technology in single cup tests with optical access and thermoacoustic measurement capabilities up to relevant operating pressures and temperatures (T3 = 950 Kelvin, P3 = 20 bar);
• Demonstration of the low NOx technology in multi-cup sector combustor tests with different thermoacoustic boundary conditions (open exit and exit restriction), and thermoacoustic as well as emission measurement capabilities up to relevant operating pressures and temperatures (T3 = 950 Kelvin, P3 = 40 bar);
• Demonstration of reliable and safe operation across relevant operating range (T3, P3, FAR: 950 Kelvin, 40 bar, at least 0.004 – 0.04) without flash-back, auto-ignition, blow-out, and over-heating of combustor hardware;
• Proof of thermoacoustic stability without excessive pressure amplitudes across relevant operating range;
• Contribution to development of EU competitiveness for low NOx hydrogen direct burn combustion technologies.

The project should address the following requirements and specifications:

• Reliable and safe combustor ignition at ground start conditions with 100% hydrogen;
• Lean blow-out within limits necessary for typical aero engine operation (FARLBO ≤ 0.004);
• Dry low NOx emissions across all engine operating conditions at least as low as current state-of-the-art which is around 50% below regulation in force (CAEP/8).
• Dry low NOx technology with potential to reduce NOx emissions further by no less than 30% compared to state-of-the-art.
• Operability and emission performance fulfilled for hydrogen temperatures in the range of 200 – 420 Kelvin;
• Efficient fuel/air mixing without flashback and autoignition across typical aero engine operating range;
• Temperatures of fuel injectors, dome, and combustor liners within limits for targeted engine life;
• Dynamic combustion pressures (P4) within limits for targeted engine life;
• Combustor length no longer than current state-of-the-art aero engine combustors.