Description du projet
Évaluation d’une chambre de combustion conçue pour de faibles émissions
Le projet CHAiRLIFT, financé par l’UE, prévoit d’évaluer une chambre de combustion innovante conçue pour la prochaine génération de moteurs à mélange pauvre. Dans cette nouvelle chambre de combustion, les flammes pulvérisées relevées seront caractérisées par un degré élevé de prémélange, ce qui permettra de réduire considérablement les émissions de NOx. Par rapport aux flammes conventionnelles stabilisées par tourbillon, les flammes pulvérisées relevées minimisent fortement le risque de retour de flamme de la chambre de combustion et réduisent la propension aux instabilités thermoacoustiques. Le projet proposera également une approche alternative au pilotage de flamme standard, permettant ainsi de réduire davantage les émissions de NOx. Des études expérimentales et numériques, dont le développement d’un modèle avancé d’atomisation par pulvérisation, seront menées pour évaluer les capacités de réduction des émissions de NOx de la nouvelle chambre de combustion.
Objectif
The main objective of the CHAiRLIFT project is to assess an innovative combustor concept capable to achieve an ultra-lean, low NOx, operation of future engines. With this combustion concept the requirements of ACARE Flightpath 2050 will be fully satisfied. The CHAiRLIFT combustor concept comprises two novel features: The first is to adopt “low swirl” lean lifted spray flames which feature a high degree of premixing and consequently significantly reduced NOx emissions. Inherent characteristics of such flames are the strongly reduced risk of flashback and a reduced susceptibility to thermo-acoustics instabilities compared to conventional swirl stabilized flames. However, such lifted flames bear the risk of lean blow out at some operating conditions. As second novelty of the CHAiRLIFT concept an alternative approach to standard flame piloting is proposed, enabling a a further reduction of NOx emissions. Stable and safe operations of the combustor are ensured by the interaction of adjacent flames in circumferential direction within the annular combustion chamber. This requires tilting of the axis of the flames relative to the axis of the machine. This design is called Short Helical Combustor (SHC). It has the advantage that no extra pilot flame is required which may produce additional NOx emissions. Additional benefits are the reduced length of the combustor. Most importantly, the turning angle of the NGV can be reduced resulting into a smaller number of NGV and hence reduced cooling air requirement.
Experimental and numerical investigations including the development of an advanced spray atomization model will be carried to assess the NOx reduction capabilities of the concept, by exploiting state of the art methodologies. To explore further NOx reduction capabilities of the concept, an advanced LBO active control will also be tested by combining ion sensor probe and plasma assisted combustion.
Champ scientifique
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RIA - Research and Innovation actionCoordinateur
50121 Florence
Italie