Comparison of wet and dry growth in artificial and flight icing conditions

The heat transfer behavior of accreting ice surfaces in natural (flight test) and simulated (wind tunnel) cloud icing conditions are studied. Observations of wet and dry ice growth regimes as measured by ultrasonic pulseecho techniques are made. Observed wet and dry ice growth regimes at the stagnation point of a cylinder are compared with those predicted using a quasi steady-state heat balance model. A series of heat transfer coefficients are employed by the model to infer the local heat transfer behavior of the actual ice surfaces. The heat transfer in the stagnation region is generally inferred to be higher in wind tunnel icing tests than in natural, flight icing conditions.