Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) - 09.19.18

Overview | Description | Applications | Operations | Results | Publications | Imagery

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The Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) experiment is conducted in the Combustion Integrated Rack (CIR) on the International Space Station, as part of the Advanced Combustion via Microgravity Experiments (ACME) project. In this experiment, an electric field with voltages as high as 10,000 volts is established between the burner and a mesh electrode. The motion of the charged ions, which are naturally produced within the flame, are strongly affected by a high-voltage electric field. The resulting ion-driven wind can dramatically influence the stability and sooting behavior of the flame. Measurements are made of electric-field strength, the ion current passing through the flame, and flame characteristics such as the size, structure, temperature, soot, and stability. Conducting the tests in microgravity allows for great simplifications in the analysis, enabling new understanding and the development of less polluting and more efficient combustion technology for use on Earth.
Science Results for Everyone
Information Pending

The following content was provided by Derek Dunn-Rankin, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom:

Principal Investigator(s)
Derek Dunn-Rankin, Ph.D., University of California, Irvine, Irvine, CA, United States

Co-Investigator(s)/Collaborator(s)
Sunny Karnani, Ph.D., U.S Army Research Laboratory, Adelphi, MD, United States
Sergey Minaev, Ph.D., Far Eastern Federal University, Vladivostok, Russia

Developer(s)
NASA Glenn Research Center, Cleveland, OH, United States
ZIN Technologies Incorporated, Cleveland, OH, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
NASA Research Office - Space Life and Physical Sciences (NASA Research-SLPS)

Research Benefits
Earth Benefits, Scientific Discovery

ISS Expedition Duration
September 2017 - October 2018

Expeditions Assigned
53/54,55/56

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • This work is based on prior foundational research including ground-based normal-gravity and microgravity studies of small gas-jet diffusion flames, with and without electric field control of the flame electrodynamics. In these studies, the gaseous fuel, which issues from the burner, is separated from the air (i.e., oxygen/inert mixture) by the flame.
  • The source of the electric-field influences resides in ion wind effects. In microgravity, where there are no density-driven buoyant effects, ion winds represent an important (and perhaps the only) body force that can be applied to manipulate combustion systems.
  • The Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) investigation uses the extended-duration microgravity environment to further understanding of electric fields in combustion processes and their potential applications. As such, this project includes both the academic study of electric field effects and consideration of the practical utilization of electrical control of combustion processes.

Description
An electric field can strongly influence flames because of its effect on the ions present as a result of the combustion reactions. The induced ion wind can modify the flame shape, alter the soot and stability limits, and direct the heat transfer. The purpose of the Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) experiment is to gain an improved understanding of flame ion production and learn how the electric field can be used to control non-premixed flames. For example, electric fields can enable stable burner operation at fuel-lean conditions with reduced pollutant emission, i.e., where the flame is not reliably sustained without the electric field. The experiment contributes to our critical understanding of combustion processes in the presence of electric fields. The experiment is conducted with gas-fueled flames, both with and without a coflow of air. In the former case, the tests are conducted using the same coflow burner used by the Coflow Laminar Diffusion (CLD) Flame experiment. An electric field is generated by creating a high voltage (up to 10 kV) differential between the burner and a flat circular mesh suspended above (i.e., downstream of) the burner. Measurements, as a function of the field strength and fuel, are taken of the ion current through the flame and the flame’s response time to electric forcing.

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Applications

Space Applications
The E-FIELD Flames research is not being conducted to serve any space applications, but it is possible that its findings could aid the development of future space-based combustion devices (e.g., for solid waste processing).

Earth Applications
The use of electric fields to control flames can reduce the production of harmful pollutants in practical terrestrial combustion. The combustion of fossil fuel is the primary human source of greenhouse gas and acid rain and furthermore creates soot, which can be beneficial but is also a health hazard. Combustion using electrical fields may also allow for more efficient combustion, reducing fuel consumption in addition to unwanted emissions.

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Operations

Operational Requirements and Protocols
The research is conducted in the Combustion Integrated Rack (CIR). The tests are configured, but not conducted, by the International Space Station (ISS) crew. The crew’s role is to set up the hardware, gas bottles, etc. for each set of tests. The most common changes include the gas bottles on the CIR and the mass flow controllers on the modular ACME chamber insert. All ACME testing is commanded from the ground, specifically from the Glenn ISS Payload Operations Center (GIPOC). The science portion of the testing is typically conducted in a nominally automated mode using pre-programmed scripts. However, it may alternately be conducted in a ‘manual’ mode, where changes are made to a control parameter in response to the analog video downlink and the numerical data available in the telemetry stream. For example, the electric field voltage can be adjusted to approach a flame’s soot or stability limit. ACME testing must not be conducted when thrusters fire or spacecraft dock or undock from ISS to ensure an acceptable acceleration environment. Data are downlinked between each set of tests, i.e., day of testing, to allow for preliminary analysis and requisite planning for subsequent testing.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites
Lasers, Flames, and Aerosols (LFA) Research Group – University of California, Irvine
ZIN Technologies, Inc.
Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) Experiment – NASA Glenn Research Center ISS Payload Operations Center
Advanced Combustion via Microgravity Experiments (ACME) – NASA Glenn Research Center
Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames) Experiment – NASA Glenn Research Center
Space Flames – social media site for news, etc. on ACME and related research

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Imagery