Measurement of Particle Size Distribution for Supercooled Large Drop conditions in the NRC’s Altitude Icing Wind Tunnel 2019-01-2010
As a result of new regulations pertaining to the airworthiness of aircraft exposed to in-flight icing conditions where maximum water drop size is greater than 100 microns (referred to as Supercooled Large Droplet (SLD) conditions), updates are required to the test facilities and simulations that will enable manufactures to certify their products under these new rules. While a number of facilities report achieving some of the conditions specified in the new regulations, questions remain as to the suitability of the instrumentation used to measure the drop size distributions of the SLD icing cloud. This study aims to provide baseline of the SLD drop size distribution in the AIWT using its standard MVD calibration instrumentation, i.e., Malvern Panalytical Spraytec particle size analyzer. This forms part of a collaborative effort between the NRC, NASA Glenn Icing Branch and the Italian Aerospace Research Centre (CIRA), to examine the suitability of current instruments in accurately measuring drop size distribution in clouds where SLD conditions are present.
David M. Orchard, Catherine Clark, Gislain Chevrette
National Research Council Canada
International Conference on Icing of Aircraft, Engines, and Structures