Experimental Study of Foreign Object Exclusion Characteristics of a Bifurcated Turboprop Inlet

In this study, the foreign object exclusion ability of a bifurcated turboprop inlet was first tested on a large-scale integrated experimental facility. The ingestion processes of bird, hailstone, and ice slab were captured by a high-speed imaging system to judge the exclusion result of these objects, while the mass of sand entering both the engine duct and bypass duct was collected to calculate the separation efficiency. The pressure pulsations on the inner wall of the inlet during the ingestion process were measured. The results indicate that the bird and hailstone were successfully excluded without damage to the engine duct for all the tested cases. An exclusion probability of about 72% is obtained for the ice slab under the tested conditions. The separation efficiency of sand is above 80% under all the testing conditions and is higher than 85% for most of the tested cases. Both the testing methods and results presented here are important to provide valuable references for both the academic and industrial communities to investigate foreign object exclusion characteristics of bifurcated turboprop and turboshaft engine inlets.