EFFECTS OF DIFFERENT PROPELLER MODELS ON OPEN ROTOR FUEL CONSUMPTION

Other conference contribution, 2013

In this study three different ways to represent a counter rotating propeller are evaluated. One where a map for a single rotating propeller is used, one where most of the swirl losses are excluded from the original map, and one where swirl losses are excluded and the position of the maximum efficiency is determined by the design disc loading. The two methods using the reduced swirl maps generate similar trends with similar size propellers for the optimal design and similar fuel burn figures. If the original single rotating map is used to represent counter rotating propellers the trends are significantly changed and are viewed to be unphysical. The optimal size propeller is then closer to 4.5 m rather than 3.5 meters. With the maps where a reduction in swirl losses are accounted for, the trends show a slightly decreasing fuel consumption with decreasing tip speed. If the single rotating propeller map is used there is an opposite trend and it is of higher magnitude.