TY - GEN
T1 - DYNAMIC CHARACTERISTICS OF THE TIP CLEARANCE FLOW BASED ON THE LEAKAGE FLOW MODEL
AU - Lin, Shiyan
AU - Li, Ruiyu
AU - Gao, Limin
N1 - Publisher Copyright:
© 2024 by ASME.
PY - 2024
Y1 - 2024
N2 - Leakage flow in the tip region significantly affects the turbomachinery performance, such as the efficiency, aerodynamic stability and noise. An accurate and in-depth understanding of the dynamic characteristics of leakage flow is the premise of the flow mechanism analysis and flow control. A simplified three-dimensional multi-wall leakage flow model was employed, which characterizes the unique geometric feature of multiple walls with a tip narrow gap and aerodynamic characteristics, i.e., the shear layer between confined jet and mainstream and the tip leakage vortex (TLV). Subsequently, the wall-adapt local eddy-viscosity large-eddy (WALE LES) simulation was used for the simulation. Based on the Liutex and Spectral proper orthogonal decomposition (SPOD) method, the flow structure, main fluctuation structure and unsteady source of the leakage flow were studied. The results shows that there are TLV, secondary tip leakage vortex (STLV) and induced vortex (IV) in the tip field driven only by the leakage flow. The main fluctuation contains the shake of the TLV’s core, breakdown of the IV and generation of the STLV. Furthermore, the STLV has a crucial influence on the development of the vortex structure and unsteady characteristic of the tip field. Kelvin–Helmholtz instability induced by the strong shear layer under the influence of small disturbances is at the bottom of the explosion. However, this cannot be resolved by the Reynolds-averaged Navier-Stokes (RANS) method.
AB - Leakage flow in the tip region significantly affects the turbomachinery performance, such as the efficiency, aerodynamic stability and noise. An accurate and in-depth understanding of the dynamic characteristics of leakage flow is the premise of the flow mechanism analysis and flow control. A simplified three-dimensional multi-wall leakage flow model was employed, which characterizes the unique geometric feature of multiple walls with a tip narrow gap and aerodynamic characteristics, i.e., the shear layer between confined jet and mainstream and the tip leakage vortex (TLV). Subsequently, the wall-adapt local eddy-viscosity large-eddy (WALE LES) simulation was used for the simulation. Based on the Liutex and Spectral proper orthogonal decomposition (SPOD) method, the flow structure, main fluctuation structure and unsteady source of the leakage flow were studied. The results shows that there are TLV, secondary tip leakage vortex (STLV) and induced vortex (IV) in the tip field driven only by the leakage flow. The main fluctuation contains the shake of the TLV’s core, breakdown of the IV and generation of the STLV. Furthermore, the STLV has a crucial influence on the development of the vortex structure and unsteady characteristic of the tip field. Kelvin–Helmholtz instability induced by the strong shear layer under the influence of small disturbances is at the bottom of the explosion. However, this cannot be resolved by the Reynolds-averaged Navier-Stokes (RANS) method.
KW - Kelvin–Helmholtz instability
KW - Large eddy simulation
KW - Simplified model
KW - Spectral proper orthogonal decomposition
KW - Tip leakage flow
UR - http://www.scopus.com/inward/record.url?scp=85204295026&partnerID=8YFLogxK
U2 - 10.1115/GT2024-124529
DO - 10.1115/GT2024-124529
M3 - 会议稿件
AN - SCOPUS:85204295026
T3 - Proceedings of the ASME Turbo Expo
BT - Turbomachinery - Axial Flow Fan and Compressor Aerodynamics
PB - American Society of Mechanical Engineers (ASME)
T2 - 69th ASME Turbo Expo 2024: Turbomachinery Technical Conference and Exposition, GT 2024
Y2 - 24 June 2024 through 28 June 2024
ER -