Large Eddy Simulation of nanosecond plasma enhanced ignition of H2 jets injected into supersonic O2 crossflow

Sharath Nagaraja, Liwei Zhang, Vigor Yang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The ignition and combustion of H2 jets injected into a supersonic O2 crossflow is investigated using high fidelity Large Eddy Simulations. Nanosecond plasma discharges are studied for their potential to produce radicals and impact on the flame-holding process. A subsonic H2 jet is injected at an angle of 60° to the vertical axis upstream of the plasma zone, whereas a sonic jet was injected transversely downstream, with the jet momentum ratios of 0.1 and 3.0 respectively. The discharge pulses are simulated using a reduced-order plasma model. The discharge domain was assumed to be a cubic region of dimensions 10×3×4 mm3 with pre-specified constant values of E/N and electron density. It is observed that atomic oxygen is the primary radical produced by the plasma pulses through electron impact dissociation of O2. The O atoms produced by the discharge and fuel from the jet are spread by the jet vortices, which then aid in rapid ignition and heat release. Radicals generated by the discharge process result in improved ignition just upstream of the second jet near the boundary regions as well at higher z/D locations. The presence of a large combustion zone at x/D = 12 excites instabilities along the jet periphery which grow downstream resulting in folding up of the shear layer and improved fuel-oxidizer mixing and combustion. Two distinct flames are observed downstream of each of the injector with the plasma source switched on. The first flame is weaker and less spread out, and acts as a source of radicals and partial products in igniting and holding a stronger flame downstream.

Original languageEnglish
Title of host publication45th AIAA Plasmadynamics and Lasers Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
ISBN (Print)9781624102905
Publication statusPublished - 2014
Event45th AIAA Plasmadynamics and Lasers Conference 2014 - Atlanta, GA, United States
Duration: 2014 Jun 162014 Jun 20

Publication series

Name45th AIAA Plasmadynamics and Lasers Conference

Conference

Conference45th AIAA Plasmadynamics and Lasers Conference 2014
CountryUnited States
CityAtlanta, GA
Period14-06-1614-06-20

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Large Eddy Simulation of nanosecond plasma enhanced ignition of H<sub>2</sub> jets injected into supersonic O<sub>2</sub> crossflow'. Together they form a unique fingerprint.

Cite this