Ice Crystal Drag Model Extension to Snowflakes: Experimental and Numerical Investigations

Abstract

To ensure safe flight under snowy conditions, aircraft manufacturers must demonstrate that each engine and its air inlet system can operate throughout the flight power range of the engine (including idling) in both falling and blowing snow conditions. This study is part of an effort to develop models for snow accretion. The focus here is on the modeling of snowflake transport by the carrier airflow and more specifically on the modeling of the drag coefficient of snowflakes. Based on comparisons between numerical and experimental results, we show that, provided that the complex shape of the snowflakes is accounted for, the models initially developed for ice crystal icing can also be used to estimate the drag coefficient of a snowflake. We also propose a methodology to estimate the geometric parameters of the drag models from two-dimensional images of the particles, which in general are the only available experimental data.