Characterization of Simulated Weather Environments In Aerospace Ground Test Cells.

Degraded performance due to surface damage of aircraft windows and antennas caused by atmospheric particle effects is currently a very serious problem. Impact testing is currently underway in ground test cells such as the wind tunnels and arc facilities located at Arnold Engineering Development Center (AEDC). For these tests, instrumentation that can determine the velocity vectors and size distribution for a wide range of particles, including irregular crystalline particles is needed. In this proposal, we describe a probe that features a combination of spatially resolved velocity vector measurement capability of an LDV with an imaging sizing method which is not restricted to spherical particles. The resulting single probe will allow simultaneous single-particle 2-dimensional velocity and irregular particle size characterization in a diameter range of 0.1 mm to 1.0 mm, with an expected accuracy of 10%, and a velocity accuracy of better than 1%. It will have an easily adjustable probe volume dimension in order to cope with the expected different number densities and will be easily moved between facilities. In addition, the probe will feature a high spatial resolution in order to asses the spatial ditribution of the particle accurately.