A differential laser Doppler anemometer (LDA) of NLR and a laser-two-focus (L2F) anemometer of DLR were selected to be installed in a research aircraft to demonstrate their capabilities for in-flight flow investigations. A ground test with the anemometers was performed before the flight tests. Experience with parallel operation of the anemometers was gained in a free jet and properties of both systems were investigated. During the flight tests the aircraft was flown in different atmospheric conditions to investigate whether the atmospheric seeding conditions are sufficient for measurements. Measurement volumes were traversed through the flow perpendicular to the fuselage. In this manner, the anemometers measured mean velocities, turbulence levels and the flow direction. The experiment showed that laser anemometry can be applied successfully for in-flight flow measurements.
[1]
Battery-driven miniature LDA-system with semiconductor laser diode
,
1988
.
[2]
A. A. Woodfield,et al.
Using an Airborne CO2 CW Laser for Free Stream Airspeed and Windshear Measurements
,
1984
.
[3]
R. Schodl.
Laser-two-focus velocimetry
,
1986
.
[4]
M Stieglmeier,et al.
Mobile fiber-optic laser Doppler anemometer.
,
1992,
Applied optics.
[5]
Cameron Tropea,et al.
In-flight velocity measurements using laser Doppler anemometry
,
1994
.
[6]
H. Mocker,et al.
Airborne laser Doppler velocimeter.
,
1974,
Applied optics.
[7]
F. Durst,et al.
A semiconductor laser-Doppler-anemometer for applications in aerodynamic research
,
1989,
International Congress on Instrumentation in Aerospace Simulation Facilitie.