Mach-Number Measurement with Laser and Pressure Probes in Humid Supersonic Flow
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چکیده
Mach-Number Measurement with Laser and Pressure Probes in Humid Supersonic Flow G. C. Herring NASA Langley Research Center, M/S 493 Hampton, VA 23681-2199 Abstract Mach-number measurements using a nonintrusive optical technique, laser-induced thermal acoustics (LITA), are compared to pressure probes in humid supersonic airflow. The two techniques agree well in dry flow (-35 °C dew point), but LITA measurements show about five times larger fractional change in Mach number than that of the pressureprobe when water is purposefully introduced into the flow. Possible reasons for this discrepancy are discussed.
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