Plasma Sensor Measurements in Pulse Detonation Engines

Measurements have been conducted in a pulse detonation and rotating detonation engine using a newly developed plasma sensor. This sensor relies on the novel approach of using an ac-driven, weakly-ionized electrical discharge as the main sensing element. The advantages of this approach include a native high bandwidth of 1 MHz without the need for electronic frequency compensation, a dual-mode capability that provides sensitivity to multiple flow parameters, including velocity, pressure, temperature, and gas-species, and a simple and robust design making it very cost effective. The sensor design is installation-compatible with conventional sensors commonly used in gas-turbine research such as the Kulite dynamic pressure sensor while providing much better longevity. Developmental work was performed in high temperature facilities that are relevant to the propulsion and high-speed research community. This includes tests performed in a J85 augmentor at full afterburner and pulse-detonation engines at the University of Cincinnati (UC) at temperatures approaching $2760^{\circ}$C ($5000^{\circ}$F).