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f c - f m. f c. f c + f m. f c. f m. f m. Plasma Anemometer for High Enthalpy Flows. OBJECTIVE: Develop a robust, high frequency response sensor for mass-flux measurements in hypersonic and high-enthalpy flows .
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fc - fm fc fc + fm fc fm fm Plasma Anemometer forHigh Enthalpy Flows OBJECTIVE: Develop a robust, high frequency response sensor for mass-flux measurements in hypersonic and high-enthalpy flows. - Frequency response ~ 1MHz. - High enthalpy capability. - Small measurement volume. - Insensitive to temperature. - Low power: 5 Watt, 1.5 kVrms. - Wireless Transmission. Spectral Energies. Approach: A.C. Glow Discharge with Amplitude Modulated Carrier High-Speed Digitizer Real Time Graphical Display A.C. Carrier fc Amplitude Modulated Carrier Modulating disturbance fm Electrode Real Time Demodulation U Velocity Fluctuations wireless Plasma Electrode facq= 100 MHz To host PC Modulated Carrier Demodulation: Separation of Carrier and Side-Bands Spectral Domain Time Domain Amplitude Modulation Carrier Carrier Gives Mean Response Side-Band Side-Band Side-Bands Give Unsteady Response Application: High Speed Boundary Layer and /Shear Flows Mach 3.5 Shear Layer Measurement Velocity Sensor: NASA Langley Mach 3.5 Facility Carrier Gives Mean Response Side-Bands Give Unsteady Response High-speed shear-layer: 600 kHz frequency response Application: Gas Turbines – Compressor, Combustor, Turbine, and Augmentor Pressure Sensor: Full-Scale GE Gas Turbine Comparison of Kulite and Plasma in Compressor Off On