Results of Holdover Time Testing of Type IV Anti-Icing Fluids With the Improved NCAR Artificial Snow Generation System
Abstract
This report discusses improvements to the National Center for Atmospheric Research (NCAR) artificial snow generation machine and the results of anti-icing fluid testing with the improved machine. The improvements include: (1) improved control of snowfall rate, (2) development of an integrated frosticator plate/snow mass measuring system, (3) automatic control and recording of the experiment, and (4) direct control of the frosticator plate temperature through an area heater controlled by an interface unit. This improved machine was used to conduct anti-icing fluid holdover time tests on several Type IV fluids. The results showed the typical inverse relationship between holdover time and snowfall rate. The results from the improved machine were compared to previous natural and artificial snow tests conducted by the University of Quebec at Chicoutimi and NCAR and showed good agreement in general. Tests with varying snowfall rates showed a factor of 1.5 to 2.0 longer holdover time for nonconstant snowfall rates. This result suggests that natural snow conditions are not as severe as the constant snowfall rate conditions tested in the laboratory. Causes for the longer holdover time were suggested to be: (1) the longer time available for the absorption of the melted snow water, and (2) the warmer temperatures experienced during the time varying rate tests as compared to the constant rate tests.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1999
- Accession Number
- ADA372713
Entities
People
- Allan Hills
- Charlie Knight
- Roy M. Rasmussen
- Scott Landolt
Organizations
- National Center for Atmospheric Research