Numerische Untersuchung von N 2 -O 2 -Plasma-Freistrahlen als plasmatechnologische Methode zur NO x -Reduktion in synthetischen Abgasen

The attempt to use microwave induced N2-O2 plasmas to reduce NOx emissions of direct injecting gasoline and Diesel engines reaching the limits of the EURO 4 exhaust gas standards is of special interest. This work makes the attempt to explore the fundamental plasmachemical reaction paths of NOx kinetics in hot thermal and cold non-thermal plasmas. To reach this aim a numerical parameter study was done to determine theoretical possible NOx reduction potentials. The analogy of plasma jets and turbulent jet flames was the reason to choose the theory of laminar diffusion flamlets of non-premixed turbulent combustion processes for the turbulent reacting flow. The turbulent flow was modelled by a standard k-epsilon model of the commercial CFD solver FLUENT. The mechanism of chemical reactions consists reactions for all ground states and electric and vibrational excited states. The results of the studies show that thermal plasmas with an oxygen part greater than 5% are not able to reduce NOx emissions. On the one hand reduction potentials were found at temperatures greater than 6000-8000 K. On the other hand a real plasma jet always consists of a hot center and a cooler zone around the center where heavy NOx producing is taking place. The results for non-thermal plasmas show theoretical reduction potentials of about 80% at temperatures of about 2000 K. This shows a good agreement with latest experimental studies. But there are still numerical and experimental studies necessary to clear the question of NOx reducing facilities of cold non-thermal plasmas.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2000

Author dc:creator

• Mikulic, Ingo

Contributors dc:contributor

• Peters, Norbert

• info:eu-repo/classification/ddc/530
• Physik
• Verbrennungsmotor
• Stickstoffoxidemission
• Emissionsverringerung
• Mikrowellenplasma
• Freistrahl
• Numerisches Verfahren

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118239%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A56114