Augmentor Screech Instability Control through Directed Plasma Discharge

Directed plasma discharge using Knite Inc.s Kinetic Spark Ignition (KSI) hardware is proposed as a means to quell augmentor screech tone. Contrary to typical plasma ignitors, where plasma discharge is between anode and cathode, the KSI can discharge plasma into the flow in a reproducible manner. This controllability was used successfully on projects to improve performance of igniters and is also key to its potential as an active combustion control (ACC) actuator. Moreover, the KSI system could potentially be the augmentor ignitor and also its ACC actuator. Tests will take place at the University of Cincinnati, in partnership with Dr. Ephraim Gutmarks research group, which has extensive experience in augmentor tests and thermoacoustic instabilities. Phase I consists of a proof-of-concept tests which evaluate the ability of the KSI system to periodically affect a flame. Two KSI actuators will run in open-loop at various frequencies and duty cycles. Plasma will act directly on the reaction zone or on secondary fuel streams to increase its impact. Phase I Option will fine-tune the setup, attempt simple closed-loop control, and begin design activity to move testing to the augmentor rig, including attempting ACC with the KSI installed at the typical ignitor location.