{"id":4353,"date":"2024-03-26T16:19:00","date_gmt":"2024-03-26T16:19:00","guid":{"rendered":"https:\/\/new.www.purdue.edu\/newsroom\/?p=4353"},"modified":"2024-08-20T12:21:22","modified_gmt":"2024-08-20T16:21:22","slug":"purdue-innovations-use-electric-fields-and-electrode-configurations-to-manipulate-a-flames-shape-heat-release","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/newsroom\/2024\/Q1\/purdue-innovations-use-electric-fields-and-electrode-configurations-to-manipulate-a-flames-shape-heat-release","title":{"rendered":"Purdue innovations use electric fields and electrode configurations to manipulate a flame\u2019s shape, heat release"},"content":{"rendered":"

WEST LAFAYETTE, Ind. —<\/p> \n

As a flame changes shape by the millisecond, its heat release and stability are affected. Purdue University researchers have created patent-pending methods to dynamically manipulate a flame \u2014 from stable to oscillating to agitated \u2014 using electric fields and electrode configurations to control its heat release.<\/p>\n<\/div>\n\n\n

The innovations could benefit companies that manufacture gas turbines for aircraft engines and electric power generation, appliances like home furnaces and water heaters, and many types of industrial burners. <\/p>\n\n\n\n

Galen King<\/a> and Dustin Cruise are among the first to conduct research on anchor points to subtly change a flame\u2019s shape and manipulate its heat release. King is a professor emeritus in the School of Mechanical Engineering<\/a>; Cruise earned his master\u2019s and doctoral degrees under King.<\/p>\n\n\n\n

The research about the electric field flame manipulation has been presented at the 2023 American Institute of Aeronautics and Astronautics SciTech Forum and Exposition and the 2023 fall meeting of the Western States Section of the Combustion Institute. <\/p>\n\n\n\n

A video showing flames being manipulated using the Purdue method<\/a> is available on the School of Mechanical Engineering\u2019s YouTube channel.<\/p>\n\n\n\n

Why flame stability matters<\/h2>\n\n\n\n

The global energy supply is predominantly met by the combustion of fossil fuels, which also is the primary source of greenhouse gas emissions. Solutions to reduce emissions can worsen flame stability.<\/p>\n\n\n\n

\u201cA lack of flame stability can lead to the flame extinguishing during operation, which has severe consequences in applications like an aircraft engine,\u201d Cruise said. \u201cIssues with flame stability also lead to a greater amount of emissions, premature burner or combustor failure, and excess noise.\u201d<\/p>\n\n\n\n

Predicting flame stability issues during the product design phase of industrial or residential products is challenging.<\/p>\n\n\n\n

\u201cDiscovering issues in preproduction testing or later is prohibitively expensive to solve through redesign, so the only solution is to avoid operating conditions that trigger stability issues,\u201d Cruise said. \u201cBut that creates a trade-off between stabilizing the flame and reducing emissions.\u201d<\/p>\n\n\n\n

The first Purdue breakthrough<\/h2>\n\n\n\n

King\u2019s and Cruise\u2019s innovations leverage the charged particles in a flame: positive and negative ions and electrons. The innovations use an applied electric field and electrodes to create multiple anchor points for a flame through the electrohydrodynamic effect. An anchor point is a location where the flame is stabilized. The electrodes are small enough not to interfere with the flame when the electric field is off.<\/p>\n\n\n\n

\u201cCreating anchor points significantly alters the flame\u2019s shape and internal volume. This allows for a novel way to affect the flame heat release,\u201d Cruise said. \u201cAffecting the heat release and having some control over it allows suppressing thermoacoustic instabilities \u2014 the uncontrolled oscillations of the flame.\u201d<\/p>\n\n\n\n

King said, \u201cIf you have multiple anchor points on the flame, as created by multiple electrodes, you can have a quasi-linear variation as you change an electric field. This allows you to implement a controller based on that electric field, which alters the flame heat release and, in turn, suppresses the thermoacoustic instability.\u201d <\/p>\n\n\n\n

The innovations also allow users to purposefully drive instabilities and oscillations to increase the flame\u2019s heat transfer, which can lead to more efficient, better heat exchangers.<\/p>\n\n\n\n

King\u2019s and Cruise\u2019s novel innovations require no moving parts, giving them greater reliability than traditional mechanical actuator designs.<\/p>\n\n\n\n

Innovations in electrode design and configurations<\/h2>\n\n\n\n

King and Cruise built upon their initial breakthrough by creating more complex electrode designs, which allow for more complicated and better control over a flame. They also created electrode pairs that remove all electrodes from within a flame. <\/p>\n\n\n\n

\u201cIn the original breakthrough, a metal electrode was physically within the flame. This would be unacceptable for many industrial applications: the electrode would erode over time and interfere with the flame and gas flow,\u201d Cruise said. \u201cThe new electrode arrangement, called the adjacent electrode configuration, builds all the electrodes into the face of the burner.\u201d <\/p>\n\n\n\n

Benefits of the adjacent electrode configuration include:<\/p>\n\n\n\n