Suppressing complex flow fields and losses in a transonic compressor with micro-structures

• A method of flow separation control by adding a micro-vortex generator to the surface of a high-load compressor blade is proposed. • The rotor blades installed with vortex generators are divided into structured grids to make the calculation results more accurate. • The vortex generator installed at the leading edge of the rotor blade increases the compressor's overall efficiency by 0.63 %. This paper focuses on a highly-loaded compressors with microstructures that are utilized to control the flow with the aim of enhancing the compressor efficiency and elucidating its complex internal flow mechanism. To this end, numerical simulations are employed to examine the flow mechanism in the near endwall zone of the highly-loaded compressor blade and to investigate the secondary flow and corner separation of the endwall under operating conditions. The impacts of influential micro-vortex generator (MVG) mechanisms on the secondary flow, as well as corner separation and laminar flow on the blade surface of the a highly-loaded compressor are investigated in some detail. The obtained results reveal that the vortex generator (VG) is capable of effectively controlling the blade surface flow separation and corner separation. Compared with the original compressor, after installing the VG, its efficiency is effectively enhanced such that the largest increase is obtained as high as 0.63 %, and its margin increase reaches 25.1 %. As the VG is installed near the leading edge of the rotor blade, it exhibits the best effect on the efficiency improvement, and when the VG is installed in the middle of the rotor blade, the largest effect is observed on the margin. The VG will induce vortices in its wake, which alters the vortex structure within the passage. This modification enhances the mixing of low-momentum fluid with the mainstream flow in the endwall region. As a result, it helps to prevent corner separation, ultimately improving overall flow performance.