A Numerical and Experimental Investigation of the Convective Heat Transfer on a Small Helicopter Rotor Test Setup

In-flight icing affects helicopter performance, limits its operations, and reduces safety. The convective heat transfer is an important parameter in numerical simulations state-of-the-art icing/de-icing codes utilize computing resources when calculating it. BEMT–RHT UVLM–RHT offer low- medium-fidelity approaches to estimate the rotor (RHT). They are based on a coupling between Blade element momentum theory (BEMT) or unsteady vortex lattice method (UVLM), CFD-determined correlation. latter relates Frossling number (Fr) Reynolds (Re) effective angle of attack (αEff). In series experiments carried out at Anti-icing Materials International Laboratory (AMIL), this paper serves as proof concept proposed correlations. objective propose correlations for experimentally measured data. Specifically, Frx correlated with Re αEff similar form CFD-based A fixed-wing setup first used preliminary step verify measurements wind tunnel (IWT). Tests conducted α = 0°, range 4.76 × 105 ≤ 1.36 106 10 non-dimensional surface wrap locations − 0.62 (S/c) + 0.87. Later, build novel correlation, tests two pitch angles ((θ) 0° 6°) speeds (500 RPM (Ω) 1500 RPM), three different radial positions ((r/R) 0.6, 0.75 0.95), 0 S/c 0.58. Results indicate that stagnation point was literature experimental data, within 8% fully turbulent CFD simulations. FrAvg also agrees predictions, average discrepancy 1.4%. For rotor, Ω caused increase θ those 6°. Moreover, behavior changed significantly r/R, suggesting had significant effect Frx. Finally, data Rem (at each S/c) establish correlation parameters, term then added account fit error 2.1% 14%, thus justifying use coupled approach UVLM–RHT.