Non-uniform compressor inflow is a common problem, not only when operating jet engines but also with industrial gas turbines. Some recent developments of modern high efficient airframe concepts e.g. consider installation of boundary layer ingesting engines, i.e. engines which are permanently impinged on by inhomogeneous inflow conditions. Therefore, the behavior of the engine’s compressor towards distorted inflow has to be taken into account already early in the design phase. The influence of distorted inflow on two different compressor stages is investigated in this paper by full-annulus 3D as well as by 2D blade-to-blade calculations. Unsteady full-annulus 3D computations of the whole compressor system are still very time-consuming. Hence, this paper investigates and validates the potential of 2D full-annulus blade-to-blade simulation. In how far the flow field can be validly predicted by 2D blade-to-blade simulations depends strongly on the radial deviation of the stream-tubes and on secondary flow effects. For this reason, this study includes two different transonic axial compressors. The first one has a high aspect ratio and a small tip clearance gap resulting in a weak tip clearance vortex and secondary flow influence. In contrast to this first one, the second compressor was designed for a 3D dominated passage flow with a small aspect ratio and a large tip clearance gap. Both compressors were simulated in 2D as well as in full 3D, with a total pressure distortion that was steady, constant in radial, but varying in circumferential direction. The objective of this study is to investigate the influence of a total pressure distortion on two different compressor stages in terms of flow field deviation and mechanical blade loading as well as to access the quality of the predicted flow-field of 2D bade-to-blade calculations, compared to full 3D calculations.    «

Non-uniform compressor inflow is a common problem, not only when operating jet engines but also with industrial gas turbines. Some recent developments of modern high efficient airframe concepts e.g. consider installation of boundary layer ingesting engines, i.e. engines which are permanently impinged on by inhomogeneous inflow conditions. Therefore, the behavior of the engine’s compressor towards distorted inflow has to be taken into account already early in the design phase. The influence of di...    »