- Context
Current energy prospects suggest the use of hydrogen (H2) and ammonia (NH3) as carbon-free energy carriers to achieve neutrality by 2050. NH3 offers advantages like high energy density and safe storage but faces combustion challenges such as narrow flammability and high NOx emissions. Interestingly, some H2 can be obtained by partial cracking of NH3 to create blends of more favourable combustion properties, with open questions regarding pollutant emissions and unburnt NH3 content.

- Challenges
Porous burners show promise for safe and low-pollutant combustion of NH3/H2 blends. However, material durability issues and the complexity of flame stabilization pose significant hurdles. Fortunately, recent advances in additive manufacturing enable the precise tailoring of porous matrices, but the experimental characterization remains difficult due to the opacity of the solid matrix.

- Research objectives
The PhD candidate will operate an experimental bench at CEA Saclay to conduct combustion experiments with NH3/H2/N2+air mixtures in various porous burners. Key tasks will include designing new burner geometries, comparing experimental results with numerical simulations, and advancing the modelling of porous burners using 1D Volume-Averaged Models and asymptotic theory. Experimental measurements will include hotwire anemometry, infrared thermometry, output gas composition analysis, chemiluminescence, and laser diagnostics. The porous burners will be manufactured using 3D printing techniques with materials such as stainless steel, inconel, alumina, zirconia, and silicon carbide.

The research aims to develop more robust and efficient porous burners for NH3/H2 combustion, enhancing their practical application in achieving carbon neutrality. The candidate will contribute to advancing the field through experimental data, innovative designs, and improved modelling techniques.