DEVELOPMENT OF ADVANCED INSTRUMENTATION FOR DROP SIZE AND LIQUID WATER CONTENT MEASUREMENTS IN CLOUDS

DEVELOPMENT OF ADVANCED DIAGNOSTICS FOR THE DETERMINATION OF THE LIQUID WATER (LWC) FOR FOG AND CLOUDS IS PROPOSED. SUCH DATA ARE FUNDAMENTAL TO THE RESEARCH IN CLOUD PHYSICS, ACID PRECIPITATION, ELECTROMAGNETIC WAVE PROPAGATION, AND AIRCRAFT ICING. CURRENTLY, THE METHODOLOGIES FOR MEASURING LWC ARE TIME-CONSUMING, LACK VERSATILITY, AND LACK ACCURACY. UNDER THIS PROGRAM, THE RECENTLY DEVELOPED PHASE DOPPLER PARTICLE ANALYZER (PDPA) WILL BE EVALUATED AS A MEANS OF PROVIDING ACCURATE DROP SIZE SPECTRA, AIRFLOW SPEED, AND NUMBER OF DROPS COUNTED IN A MEASURED PERIOD OF TIME. THESE RESULTS ARE NEEDED ALONG WITH THE SAMPLING CROSS SECTION TO ESTABLISH THE LWC. CRITICAL QUESTIONS ON THE SYSTEM PERFORMANCE IN LOW TEMPERATURE ENVIRONMENTS AND ON AIRCRAFT WILL BE ADDRESSED. DEMONSTRATIONS ON THE CONSISTENT LEVELS OF ACCURACY IN THE MEASUREMENT OF THE LWC WILL BE PERFORMED. EVALUATIONS WILL BE MADE BY GENERATING SPRAYS OF SIZE DISTRIBUTIONS SIMILAR TO FOG AND CLOUDS WITH KNOWN LWC. MEASUREMENTS OF THESE SPRAYS WILL BE PERFORMED WITH THE PDPA AND COMPARED TO THE KNOWN NOZZLE FLOW RATES. THESE MEASUREMENTS WILL BE MADE IN THE AEROMETRICS' TWO-PHASE FLOW WIND TUNNEL AT A RANGE OF CONVECTION VELOCITIES.