Study on the Minimum Anti-Icing Energy Based on the Icing Limit State

Abstract

This investigation presents a new approach for calculating the minimum aircraft anti-icing heat load based on an icing limit state in which all of the heat fluxes on the outer surface of the skin reach equilibrium without having additional heat supplied to the skin and there is no ice formation. Different from the conventional method where the surface temperature is assumed to be a constant value (for example, 4 or 20°C), this investigation uses a surface temperature distribution in the icing limit state to calculate the anti-icing heat load of the flight conditions, which avoids the randomness of the assumed temperature value and provides a theoretical reference for the aircraft anti-icing heat load calculation. A relevant calculation code is developed using the Visual Basic .NET language. This investigation calculates the minimum anti-icing heat load of a DFVLR R-4 airfoil in numerous cases and compares the results with those for which the surface temperatures are 10 and 20°C. The results indicate that the approach in this investigation not only meets the requirements of anti-icing but also saves energy on the aircraft to a certain extent.