Post discharge evolution of a spark igniter kernel

Sforzo, Brandon; Lambert, Alexander; Kim, Jaecheol; Jagoda, J.; Menon, Suresh; Seitzman, Jerry M.

doi:10.1016/j.combustflame.2014.07.024

Cited by 36 publications

(18 citation statements)

References 31 publications

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“…Readers are referred to [17,18] for further details regarding the formation number of vortex rings and its implications on vortex ring dynamics. Similar observations relating to kernel entrainment, expansion, and trailing column have been documented for kernels discharged using a pulsed plasma jet igniter [13], a laser [15], and dielectric gap [11,20,39].…”

Section: Resultssupporting

confidence: 70%

“…This was a consequence of the flow being entrained into the center of the vortex. Toroidal vortices in the spark kernel literature have been shown to develop from fluid entrainment caused by either a surface (i.e., electrode) [11,20] or as a consequence of being pulsed into a fluid [13,16]. The kernels discussed in this work belong in the latter mechanism.…”

Section: Resultsmentioning

confidence: 97%

“…Not considering the kernel's trajectory and development may lead to placement in a location that reduces the ignition performance. Sforzo et al [11] studied kernels exiting into a uniform crossflow (33 m∕s) using highspeed schlieren with coupled emission imaging and computational modeling. 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].…”

Section: Introductionmentioning

confidence: 99%

“…Sforzo et al [11] studied kernels exiting into a uniform crossflow (33 m∕s) using highspeed schlieren with coupled emission imaging and computational modeling. 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.…”

Section: Introductionmentioning

confidence: 99%

“…Despite the significance, only a few studies have sought to determine the temperature of kernels after the initial plasma. Sforzo et al [11] simulated and experimentally determined the kernel temperature for a single nonreactive crossflow (33 m∕s). Kernel temperatures were assumed to be uniformly distributed and were determined from a combination of schlieren imagery and detailed energy deposition information.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Temperatures of Spark Kernels Discharging into Quiescent or Crossflow Conditions

Okhovat

Hauth

Blunck

2017

Journal of Thermophysics and Heat Transfer

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This work determines how the temperature of spark kernels changes for quiescent and crossflow conditions. Previous efforts have primarily considered kernels in quiescent conditions and typically neglected how the temperature changes with time. The latter is significant because the temperature evolution is critical for determining if reactions become self-sustaining. Kernels were generated using a gas turbine engine igniter. Temperatures were determined from radiation intensity measurements (FLIR SC6700) and by solving the radiation transfer equation. Kernels were discharged into a wind tunnel with crossflow velocities between 0 and 15.6 m∕s. Kernels developed into toroidal vortices for all conditions. The average peak temperature in quiescent conditions was near 950 K and nearly 1250 K at the highest crossflow velocity. Higher temperatures were observed at the upstream side of kernels when ejecting into a crossflow. The changes in temperatures observed with crossflow are explained by fluid mechanic literature; vortex crossflow interaction alters entrainment into kernels. The sensible energy of kernels, determined from the temperatures, decreased roughly linearly with time for all flow conditions. The highest crossflow velocity had the lowest sensible energy as a result of reduced apparent volume of the kernel. The trajectory of kernels in a crossflow matches that from pulsed jet literature.

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