Super-cooled Large Droplets consideration in the droplet impingement simulation for aircraft icing

Aircraft ice accretion due to Super-cooled Large Droplets (SLD) has been widely concerned since the Roselawn accident, and the airworthiness authority has issued a new notice of proposed rulemaking aiming to the icing condition of SLD. To extend the current water droplet impingement computation code to cover the range of SLD, some typical SLD splashing models was introduced first, and the methods to integrate an empirical SLD model into current impingement code was discussed, although the code has been validated partially in both 2D and 3D conditions for the normal icing envelope defined in CCAR 25 APPENDIX C. Through the comparison of impingement results with the SLD experiment and LEWICE, it could be found that the empirical SLD model can deal with SLD impingement but still need many improvements.