Project Title:
Compact Diode-Laser-Based Inlet and Exhaust Mass-Flow Flight Instrument
92-1-03.06-0003 NAS02-13730
Compact Diode-Laser-Based Inlet and Exhaust
Mass-Flow Flight Instrument
Physical Sciences, Inc.
20 New England Business Center
Andover, MA 01810
Mark G. Allen (508-689-0003)
Abstract:
Recent advances in compact, tunable, room-temperature, diode
lasers now permit sensitive measurement of gas dynamic properties
with low-power, small-volume, low-cost instrumentation. Currently,
laboratory demonstrations of path-averaged density and velocity
measurements in flows depend on high-frequency modulation
techniques to achieve the required sensitivity for practical, in-
flight applications. This project addresses a new concept for
ultra-sensitive, mass-flux measurements using a novel detection
system that eliminates the need for complex, high-bandwidth
modulation and detection strategies. Shot-noise-limited
sensitivity is achieved using conventional detectors and
amplifiers in a novel transistor-pair combination. Inlet mass flux
is determined from simultaneous, non-intrusive O2 density and
velocity measurements. Exhaust mass flux is determined from
combined O2 and H2O measurements. The two measurements are
determined to form a real-time thrust determination. Phase I will
demonstrate the sensitivity required for typical flight conditions
with typical absorption path lengths and optical access
limitations. This data will be used to complete a preliminary
design of a prototype brassboard instrument. Phase II will develop
and test the prototype in a simulation facility at the company.
Potential Commercial Application:
Potential Commercial Applications: The mass-flux monitor is
expected to have a broad commercial application in the civilian
and defense aerospace industry. In addition, the ultra-sensitive
detection system will be applicable to a wide range of gas
emission monitoring systems.
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