Hot-Air Anti-Icing Heat Transfer and Surface Temperature Modeling

Abstract

An inlet strut with a hot-air anti-icing system is studied experimentally and numerically to understand the heat transfer between impinged supercooled water droplets and solid surfaces. Experiments were performed in an icing research wind tunnel for dry (without water droplets) and sprayed cases. The results show that the impinged droplets can decrease the surface temperature, even on areas without droplet impingement or a water film. Theoretically, the impinged droplets exchange heat with solid surfaces through two heat flow rate terms: , which contains the kinematic and internal energies of the impinged droplets; and the evaporation energy . Adding these two terms to the solid surface when simulating the dry case provides a method to predict the surface temperature after spraying. Calculations for depend on the film coverage that varies due to different operating conditions. However, calculating for the impinged area or over the entire surface can give the upper and lower bounds of the prediction for surface temperature. The results show that both methods can give predictions with errors that are below 5% for all cases studied. The numerical results also show that both and decrease the surface temperature, whereas the effect of is neglectable when compared with .