The detrimental effects of some meteorological
phenomenon such as wind shear, thunderstorm, ice/snow etc, to aviation safety are relatively well known. But aerodynamic influences due to heavy rain are still an on-going research
subject, and needs further investigation. In the past decade there are neither experimental nor numerical researches on heavy rain aerodynamics except our numerical simulation conducted at 2003. This paper first review some research
finding of heavy rain effects on aerodynamic performance degradation. To further investigate the rain physics, CFD method and preprocessing grid generator are used as our main analytical tools, and the simulation of rain is accomplished via two-phase flow approach’s Discrete Phase Model (DPM). The current discoveries of a typical commercial airfoil show that this research successfully simulates the low speed aerodynamic
efficiency degradation under the heavy rain. The degradation rate increases with the rain rate, and the premature stall phenomenon is also reported. It is expected that the quantitative information gained in this paper will be useful to
the operational airline industry, and greater effort such as flight test should put in this direction to further improve aviation safety.
