Abstract

A particle-in-cell (PIC) model is constructed for a ∼100 μm field-emission dielectric barrier discharge (FE-DBD) actuator in atmospheric pressure mixtures of oxygen, hydrogen, and water vapor. The discharge is characterized, including the effects of gas temperature and gas composition. Quantities relevant to plasma-coupled combustion, such as Joule heating, Lorenz body force, and radical generation are estimated for gas temperatures and compositions relevant for combustion energy conversion. Due to its low ionization energy, O2 increases the magnitude of Joule heating and body forces in the discharge. However, water vapor weakens these effects because of its high ionization energy and many excitational degrees of freedom that remove energy from electrons through inelastic collisions. At higher gas temperatures the discharge becomes more diffuse on account of lower gas densities. At room temperature, and operated at an easily achieved 300 V at 10 MHz, the FE-DBD produces both intense local body forces (107 N/m3) and Joule heating (109 W/m3) at the corner of the exposed electrode. A boundary layer model provides an estimate that the FE-DBD can induce flow velocities of around 10-20 m/s and temperature increases of around 5-20 K in room temperature H2/O2/H2O mixtures. Sources based on the PIC model are applied in continuum simulations of non-premixed hydrogen combustion in a microchannel. Without the FE-DBD, the inflow of fuel and oxygen is hindered by viscous losses, thermal conduction to wall boundaries, and thermal expansion of gasses, leading to flame extinction. The FE-DBD actuators pre-heat and dissociate the fuel and produce body forces that counter viscous resistance, sustaining combustion. In another example, FE-DBD plasma coupling reduces the autoignition time of a stoichiometric, 950 K H2-O2 mixture from 117 μs to 49 μs.

Original languageEnglish (US)
Article number085007
JournalPlasma Sources Science and Technology
Volume27
Issue number8
DOIs
StatePublished - Aug 9 2018

Fingerprint

field emission
augmentation
hydrogen
Joule heating
gas composition
gas temperature
water vapor
actuators
vapors
ionization
spontaneous combustion
rarefied gases
sustaining
inelastic collisions
energy conversion
high temperature gases
room temperature
oxygen
microchannels
cells

Keywords

  • combustion
  • field-emission
  • hydrogen
  • micro-plasma
  • oxygen
  • plasma actuator
  • plasma assisted combustion

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Enhancement of hydrogen microcombustion via field-emission dielectric barrier discharge. / Mackay, Kyle K.; Freund, Jonathan; Johnson, Harley T.

In: Plasma Sources Science and Technology, Vol. 27, No. 8, 085007, 09.08.2018.

Research output: Contribution to journalArticle

@article{f52bbd721a2546e580363230169c0a28,
title = "Enhancement of hydrogen microcombustion via field-emission dielectric barrier discharge",
abstract = "A particle-in-cell (PIC) model is constructed for a ∼100 μm field-emission dielectric barrier discharge (FE-DBD) actuator in atmospheric pressure mixtures of oxygen, hydrogen, and water vapor. The discharge is characterized, including the effects of gas temperature and gas composition. Quantities relevant to plasma-coupled combustion, such as Joule heating, Lorenz body force, and radical generation are estimated for gas temperatures and compositions relevant for combustion energy conversion. Due to its low ionization energy, O2 increases the magnitude of Joule heating and body forces in the discharge. However, water vapor weakens these effects because of its high ionization energy and many excitational degrees of freedom that remove energy from electrons through inelastic collisions. At higher gas temperatures the discharge becomes more diffuse on account of lower gas densities. At room temperature, and operated at an easily achieved 300 V at 10 MHz, the FE-DBD produces both intense local body forces (107 N/m3) and Joule heating (109 W/m3) at the corner of the exposed electrode. A boundary layer model provides an estimate that the FE-DBD can induce flow velocities of around 10-20 m/s and temperature increases of around 5-20 K in room temperature H2/O2/H2O mixtures. Sources based on the PIC model are applied in continuum simulations of non-premixed hydrogen combustion in a microchannel. Without the FE-DBD, the inflow of fuel and oxygen is hindered by viscous losses, thermal conduction to wall boundaries, and thermal expansion of gasses, leading to flame extinction. The FE-DBD actuators pre-heat and dissociate the fuel and produce body forces that counter viscous resistance, sustaining combustion. In another example, FE-DBD plasma coupling reduces the autoignition time of a stoichiometric, 950 K H2-O2 mixture from 117 μs to 49 μs.",
keywords = "combustion, field-emission, hydrogen, micro-plasma, oxygen, plasma actuator, plasma assisted combustion",
author = "Mackay, {Kyle K.} and Jonathan Freund and Johnson, {Harley T}",
year = "2018",
month = "8",
day = "9",
doi = "10.1088/1361-6595/aad43c",
language = "English (US)",
volume = "27",
journal = "Plasma Sources Science and Technology",
issn = "0963-0252",
publisher = "IOP Publishing Ltd.",
number = "8",

}

TY - JOUR

T1 - Enhancement of hydrogen microcombustion via field-emission dielectric barrier discharge

AU - Mackay, Kyle K.

AU - Freund, Jonathan

AU - Johnson, Harley T

PY - 2018/8/9

Y1 - 2018/8/9

N2 - A particle-in-cell (PIC) model is constructed for a ∼100 μm field-emission dielectric barrier discharge (FE-DBD) actuator in atmospheric pressure mixtures of oxygen, hydrogen, and water vapor. The discharge is characterized, including the effects of gas temperature and gas composition. Quantities relevant to plasma-coupled combustion, such as Joule heating, Lorenz body force, and radical generation are estimated for gas temperatures and compositions relevant for combustion energy conversion. Due to its low ionization energy, O2 increases the magnitude of Joule heating and body forces in the discharge. However, water vapor weakens these effects because of its high ionization energy and many excitational degrees of freedom that remove energy from electrons through inelastic collisions. At higher gas temperatures the discharge becomes more diffuse on account of lower gas densities. At room temperature, and operated at an easily achieved 300 V at 10 MHz, the FE-DBD produces both intense local body forces (107 N/m3) and Joule heating (109 W/m3) at the corner of the exposed electrode. A boundary layer model provides an estimate that the FE-DBD can induce flow velocities of around 10-20 m/s and temperature increases of around 5-20 K in room temperature H2/O2/H2O mixtures. Sources based on the PIC model are applied in continuum simulations of non-premixed hydrogen combustion in a microchannel. Without the FE-DBD, the inflow of fuel and oxygen is hindered by viscous losses, thermal conduction to wall boundaries, and thermal expansion of gasses, leading to flame extinction. The FE-DBD actuators pre-heat and dissociate the fuel and produce body forces that counter viscous resistance, sustaining combustion. In another example, FE-DBD plasma coupling reduces the autoignition time of a stoichiometric, 950 K H2-O2 mixture from 117 μs to 49 μs.

AB - A particle-in-cell (PIC) model is constructed for a ∼100 μm field-emission dielectric barrier discharge (FE-DBD) actuator in atmospheric pressure mixtures of oxygen, hydrogen, and water vapor. The discharge is characterized, including the effects of gas temperature and gas composition. Quantities relevant to plasma-coupled combustion, such as Joule heating, Lorenz body force, and radical generation are estimated for gas temperatures and compositions relevant for combustion energy conversion. Due to its low ionization energy, O2 increases the magnitude of Joule heating and body forces in the discharge. However, water vapor weakens these effects because of its high ionization energy and many excitational degrees of freedom that remove energy from electrons through inelastic collisions. At higher gas temperatures the discharge becomes more diffuse on account of lower gas densities. At room temperature, and operated at an easily achieved 300 V at 10 MHz, the FE-DBD produces both intense local body forces (107 N/m3) and Joule heating (109 W/m3) at the corner of the exposed electrode. A boundary layer model provides an estimate that the FE-DBD can induce flow velocities of around 10-20 m/s and temperature increases of around 5-20 K in room temperature H2/O2/H2O mixtures. Sources based on the PIC model are applied in continuum simulations of non-premixed hydrogen combustion in a microchannel. Without the FE-DBD, the inflow of fuel and oxygen is hindered by viscous losses, thermal conduction to wall boundaries, and thermal expansion of gasses, leading to flame extinction. The FE-DBD actuators pre-heat and dissociate the fuel and produce body forces that counter viscous resistance, sustaining combustion. In another example, FE-DBD plasma coupling reduces the autoignition time of a stoichiometric, 950 K H2-O2 mixture from 117 μs to 49 μs.

KW - combustion

KW - field-emission

KW - hydrogen

KW - micro-plasma

KW - oxygen

KW - plasma actuator

KW - plasma assisted combustion

UR - http://www.scopus.com/inward/record.url?scp=85053121692&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85053121692&partnerID=8YFLogxK

U2 - 10.1088/1361-6595/aad43c

DO - 10.1088/1361-6595/aad43c

M3 - Article

AN - SCOPUS:85053121692

VL - 27

JO - Plasma Sources Science and Technology

JF - Plasma Sources Science and Technology

SN - 0963-0252

IS - 8

M1 - 085007

ER -