Development and Evaluation of Trajectory-Insensitive Particle Measurement Methods for Icing Cloud Characterization

The Phase I feasibility study was successfully completed and we demonstrated that the two proposed methods for characterizing icing clouds associated with helicopter icing environments performed as expected or better and can meet all the requirements outlined in the Army's request. One of the important requirements for these probes is the ability to measure spray droplets moving over a very wide range of angles of trajectory. The methods evaluated were the phase Doppler interferometry technique that will be developed into a dedicated extended range cloud probe (PDI ExR CP) for helicopter icing research. This probe will also be commercialized for a much wider range of applications. The high-speed multi-beam imaging (HSI) probe was shown to be capable of measuring droplets and irregular-shaped particles such as ice crystals in mixed phase flows. This method also will be commercialized to cover a much broader range of applications. Under the Phase II program, the probes will be further designed, built, tested and delivered to the Army. Instrument electronics components will be incorporated onto PC boards and made ready for the probe installation. The probe will be evaluated in various icing facilities before delivering to the Army for incorporation into their helicopter icing program.