The study of droplet array combustion on TEXUS-46-preliminary scientific results of the Nitrogen Oxide production

Lean, partially premixed, swirl-stabilized spray fiames are diseussed for novel combustion concepts to allow a further abatement of the nitrogen oxides (NO _x) émissions. The relevant knowledge for those concepts is based on combustion research of manageable and observable droplet regimes. This paper initially présents the experiment setup for the combustion of a linear n-decane droplet array under microgravity conditions. After pointing out ail relevant aspects of the associated exhaust gas sampling and analysis processes, the final focus is set on the results of the exhaust gas production. A wide range of the degree of droplet prevaporization is investigated. The PHOENIX experiment ("Investigation of Partial Prevaporization Effects in High Temperature on Evolution of Droplet Array Combustion and Nitrogen Oxides Formation") on the TEXUS-46 sounding rocket mission was conducted against this background. Three successful combustion runs could be performed during this mission. Scientific quality and consistency of the results are high. The results on CO ₂ and CO are in line with combustion theory, and their absolute values are of the correct order of magnitude but not yet corrected for secondary effects. The NO _x émissions decrease with an increase of pre-vaporization rate Ψ. However, a straightforward portability of the derived NO _x production characteristics to technical applications needs to be assessed carefully on the basis of the prevailing droplet burning regime.