Spatial Development and Temperature of Spark Kernels Exiting into Quiescent Air

Temperatures of Spark Kernels Discharging into Quiescent or Crossflow Conditions

“…As a result, surrounding fluid is advected into the center of the kernel. Blunck et al [13] noted that kernels discharged from a pulsed plasma igniter had a trailing tail of fluid, which had been previously observed for toroidal vortices [16][17][18][19]. Additionally, Blunck et al concluded that buoyancy forces tended to be insignificant for this igniter.…”

“…Intensity emissions from the plate just before and after the kernel were subtracted from the measurements to only consider emissions from the kernels. This is similar to the approach used by Blunck et al [13]. A spark event was considered to be the time from when plasma was identified to the time at which the kernel was no longer detected.…”

“…The approach used is similar to the work by Blunck et al [13]. RADCAL is used to solve the radiation transfer equation for a nonscattering participating medium [23,24],…”

“…The group concluded that the kernel developed into a toroid following plasma generation and that the kernel volume increased due to entrainment of the surrounding fluid [11]. Many researchers have observed kernels developing into toroids [12][13][14][15] in quiescent conditions. As a result, surrounding fluid is advected into the center of the kernel.…”

“…This difference was attributed to the increased mixing caused by vortices induced from the electrodes. Blunck et al [13] found that the kernel temperature typically decreased by 30% over 2 cm of spark kernel movement for quiescent conditions. Relatively hot gases were contained within the torus ring, while surrounding air was entrained into the center and reduced the temperature.…”