A research project is underway to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the NASA Glenn Icing Research Tunnel (IRT) has been performed, including additional data taken to extend the database in the Super-cooled Large Drop (SLD) regime. The project shows the differences in ice shape between LEWICE 3.2.2, GlennICE, and experimental data.
The Icing Branch at NASA Glenn has produced several computer codes over the last 20 years for performing icing simulation. While some of these tools have been collaborative projects, most have been developed primarily by one person, with some assistance by others. The state of computing has also changed dramatically in that time period. As these codes have grown in complexity and have been accepted by users as production icing tools, there has arisen a need for the developers to adhere to standard software practices used to develop commercial software.
The project addresses the validation of the software against a recent set of ice-shape data in the SLD regime. This validation effort mirrors a similar effort undertaken for previous validations of LEWICE. Those reports quantified the ice accretion prediction capabilities of the LEWICE software. Several ice geometry features were proposed for comparing ice shapes in a quantitative manner. The resulting analysis showed that LEWICE compared well to the available experimental data.
The effects of super-cooled large droplets in icing have been researched extensively since 1994. Since then, several experimental efforts have been made to document SLD ice shapes and to investigate the underlying physics. While this project provides comparisons to standard icing conditions, the emphasis was placed on the newer data, which is predominately SLD.
This work was done by William Wright, Mark G. Potapczuk, and Laurie H. Levinson of Glenn Research Center. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Information Sciences category.
Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-18451-1.