The effect of upstream wake vortex on the unsteady characteristics of downstream tip leakage flow (TLF) in a high-loading counter-rotating compressor, have been revealed. For the strength of the tip leakage vortex (TLV) is stronger than that of the upstream wake vortex and the TLF spills from the leading edge (LE) of the neighbor blade under near stall (NS) condition, the wake vortex can only transport bypass the interface, formed by the TLF and main flow, just below the tip. The TLV is separated into several parts by the wake vortex such that it weakened rapidly and the dominant frequency of the static pressure fluctuation near the trailing edge (TE) is about 1 relative blade passing frequency (RBPF) under the NS condition. When the extent of TLV breakdown is enough, the TLV is responsible for the dominant frequency near the LE. Therefore, there are two dominant frequencies (one is located near LE, the other is located near TE) in the tip region of the downstream supersonic rotor under NS condition. It’s harmful for the stable operation of compressors due to lower frequency resulting from TLV. At small tip clearance size, affected by the upstream wake vortex, when the static pressure fluctuation caused by the TLV at the LE of the downstream rotor just appeared, the momentum ratio increases. And it locates above the limit line (applied to judge the static pressure fluctuation caused by the self-excitation of the TLF), this means the wake vortex is beneficial to suppress the self-excitation of the TLF.

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A thermoelastohydrodynamic (TEHD) coupling model is developed to study the static performance of a heavy-duty tilting pad thrust bearing (TPTB) under the effect of axis misalignment. To ensure the validity in calculating thermoelastic deformation, the calculation accuracy of the mechanical and thermal deformations used in the TEHD model is verified by the finite element method (FEM). The influence of the TEHD model on the flow state prediction is determined using different axial loads, and the numerical analysis of turbulence model and centrifugal inertia term on the bearing pad temperature is conducted at various operating rotation speeds. Compared with the aligned bearing performance, the characteristic distribution of each bearing pad under different misaligned angles is obtained. The effect of misalignment will cause local overheating of the thrust-bearing pads, especially for the heavy-duty TPTD. The results of this study can help to improve the prediction accuracy of heavy-duty TPTB characteristics and avoid harmful misalignment effects. Therefore, it is necessary to consider the effects of misalignment, turbulence, and thermoelastic deformation in the design and analysis of thrust bearings.