Comparison of LEWICE 1.6 and LEWICE/NS with IRT experimental data from modern air foil tests

A research project is underway at NASA Lewis to produce a computer code which can accurately predict ice growth under any meteorological conditions for any aircraft surface. The most recent release of this code is LEWICE 1.6. This code is modular in design and can use flow codes other than the default potential flow code. Methods for assessing the capabilities of ice accretion prediction codes are examined by comparing geometric and aerodynamic characteristics of computationally generated and experimentally measured ice shapes. The data used in this paper comes from tests performed in the NASA Lewis Icing Research Tunnel (IRT). This paper will present comparisons with that data for both ice shape and performance results. A group of geometric characteristics for quantitatively describing ice shape profiles are introduced and used to assess the differences between profiles. An aerodynamic analysis of computational and experimental ice shapes is performed using a structured-grid, Navier-Stokes, flow code as an alternate method for assessing ice shape similarity. Results indicate that large differences in ice shape are reflected in the resulting aerodynamics but are not necessarily apparent in integrated force parameters such as lift or drag.