Project Title:
Optical Technique to Study the Impact of Heavy Rain on Aircraft Performance
03.02-8477
Optical Technique to Study the Impact of Heavy Rain on Aircraft Performance
Spectron Development Laboratories Inc.
3303 Harbor Blvd., Suite G-3
Costa Mesa
CA
92626
Hess
Cecil F.
NAS1-18242
Amount:
LaRC
NAS1-17932
Abstract:
A technique to measure the size, velocity, and concentration of raindropsin very heavy rain is proposed. Studies conducted during Phase I show the feasibility
of this technique under simulated very heavy rain experiments. In Phase II, a working
prototype will be produced and demonstrated in the 4 x 7 m wind tunnel at NASA Langley.
The technique bases the size of the drops on the intensity of the light scattered
at a prescribed solid angle, and the velocity on the classical Doppler frequency.
The Phase I studies showed that spray interference had no significant effect on
the size distribution, and an accurate size obtained. The studies also include a
scattering model for nonspherical drops which helps establish the optical conditions
less sensitive to droplet shape.
These studies also point out that to measure the flows expected at NASA's facilities,
a more powerful laser and faster electronics are needed. These elements will be
incorporated in the advanced
prototype developed during Phase II.