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Shape memory alloys (SMAs) are witnessing a surge in industrial applications, with NiTiHf emerging as a leading candidate for solid-state actuation. This alloy stands out due to its high transformation [...]

Knowledge of local heat transfer coefficients is essential to understanding and successful modeling of the ice accretion process on airfoils. Ice can change airfoil shape, alter the aerodynamic behavior, and impact aircraft performance and control. This paper reports measurements of local heat transfer coefficients (Frossling number) around a 28% thickness ratio airfoil covering 90% of both the top and bottom surfaces. Measurements were conducted at a constant wall temperature for angles of attack from -8.5 to 19.5 deg, freestream Math numbers from 0.055 to 0.246, and chord Reynolds numbers from 2.5 x [10.sup.5] to 10.85 x [10.sup.5]. Static pressures were measured simultaneously at the same operating conditions. The results show that the heat transfer coefficient starts high at the stagnation point, decreases with the developing laminar boundary layer, and then increases through a region of transition to a peak at the onset of the turbulent boundary layer. Thereafter, the heat transfer coefficient slowly decreases as the thickness of the turbulent boundary layer increases. The location of the onset of turbulence moves toward the leading edge on the top surface and toward the trailing edge on the bottom surface with increasing angle of attack at a constant Reynolds number. This transition is also affected by the Reynolds number. The measured surface static pressure coefficients provide additional evidence to the changing trend of the transition locations; that is, that the location where the abrupt jump in the Frossling number occurs closely coincides with the state change from a negative pressure gradient to a positive gradient. DOI: 10.2514/1.44093