Analysis of Different POD Processing Methods for SPIV-Measurements in Compressor Cascade Tip Leakage Flow

Shi, Lei; Ma, Hongwei; Wang, Lixiang

doi:10.3390/en12061021

Cited by 14 publications

(3 citation statements)

References 46 publications

(74 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Five equal space sections are extracted from 0.5c to 0.9c to conduct a detailed analysis of the wandering properties. In this section, the motion of the vortex core is identified by the Q criterion and vortex boundary fitting, and the ellipse method identifies the identity core [31,46]. In Fig.…”

Section: Tip Leakage Vortex Wandering Behaviormentioning

confidence: 99%

Analysis of Tip Leakage Vortex Instability and Blade Force in a Low-Speed Compressor Cascade

Wang,

Ma,

Yang

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Turbulence model Detached Eddy Simulation (DES) is utilized to conduct detailed research on the tip leakage flow (TLF) instability and its influence on the compressor cascade blade static pressure distribution. The objectives are to investigate the tip leakage flow instability and blade aerodynamic force oscillation at 0deg incidence design state. This research found that the trailing edge leakage vortex and the secondary leakage vortex mixed with the leakage vortex along the backflow direction and involved into the main leakage flow, which is close to the adjacent blade pressure side. The trailing edge broken tip leakage vortex has influenced the adjacent blade pressure side static pressure distribution and vorticity transformation in the tip region. More substantial convective effects are captured in 0.95span compared with 0.7span, based on the vorticity transport equation, which confirmed the tip leakage vortex caused momentum transfer in the tip region occupies a dominant role among the spanwise. The vortex core identification has revealed the tip leakage vortex wandering in the passage. The data-driven decomposition methods proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) helped clarify that the tip leakage vortex has a distinct influence on the adjacent blade pressure side static pressure spatial distribution. The frequency spectrum analysis of blade aerodynamic force indicated that some frequency components are close to the monitored tip region velocity. Then, the DMD characteristic frequency and POD time coefficient frequency corresponding with the mode vortex cohesive structure filled the gap in visualizing the vortex structure with its characteristic frequency, which caused the blade aerodynamic oscillation. Tip leakage vortex instabilities and their influence on the blade are well analyzed. Predicted tip leakage vortex instabilities and the blade force oscillation can utilized in the compressor blade vibration design and flow control.

show abstract

Section: Tip Leakage Vortex Wandering Behaviormentioning

confidence: 99%

Analysis of Tip Leakage Vortex Instability and Blade Force in a Low-Speed Compressor Cascade

Wang,

Ma,

Yang

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The POD method can decompose the main flow structure in the flow field according to the proportion of the energy, and it not only helps in analyzing a specific mode structure independently but also removes the minor structures through reconstructing the flow field with the first few modes. The POD is based on the snapshots of the instantaneous results in this paper, and the data proceeding process is listed as follows, and detailed information can be found in Shi et al (2019).…”

Section: Proper Orthogonal Decomposition and Dynamic Mode Decompositi...mentioning

confidence: 99%

Active Flow Control Based Bleed in an Axial Compressor Cascade Using Large Eddy Simulation

et al. 2022

View full text Add to dashboard Cite

The performance of the compressor is of great importance in developing advanced engine technology, and it dramatically influences the cycle efficiency and safety of the engine. The compressor bleed requires a part of the main flow extraction from the passage, and the removal of the airflow plays an essential role in the performance of the compressor. The influence of the constant suction and pulsed suction on the flow structures and the aerodynamic performance in a compressor cascade, and the control mechanisms are numerically studied using large eddy simulation. At a suction mass flow rate of 0.25% of the main flow rate, constant suction leads to a 9.36% reduction in Cpt, while pulsed suction gains 24% more benefit in Cpt reduction on the basis of the constant suction with an excitation frequency of 100 Hz. It indicates that the pulsed suction has more significant potential to control the loss generation in the compressor. Afterward, the flow field of the baseline, constant suction, and pulsed suction are compared to find out the flow control mechanisms of the constant suction and pulsed suction. Two different formation mechanisms of the passage vortex are found due to the excitation effect of the pulsed suction. Besides, the results of proper orthogonal decomposition and dynamic mode decomposition show that the pulsed suction can simplify and stabilize the compressor flow field, which could lead to a further benefit in Cpt.

show abstract

“…Lumley 17 investigated flow turbulent characteristics by using POD method. Shi et al 18 applied POD to research tip leakage flow characteristics of compressor. POD method is also applied to investigate the turbulent characteristics of the flow around a cylinder.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the relationship between turbulence characteristics and loss mechanism in the tip leakage flow of turbine blade

Chen

Yuan

2021

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

The tip leakage flow passed over the tip clearance makes the flow very complicated near the tip gap, and the interaction of the tip leakage vortex and endwall vortex enhances the instability of the flow. Accurately capturing detailed flow structures and investigating the relationship between the flow structures and loss are beneficial for understanding the flow physics and providing guidance on reducing the loss. Due to the conventional Reynolds Averaged Navier-Stokes (RANS) methods is limited to predict the complex turbulence structures of the tip clearance flow, high fidelity simulation approaches are needed. In this work, the hybrid RANS/Large Eddy Simulation (LES) is adopted to simulate the tip leakage flow in linear cascade and demonstrates its ability to capture the small-scale flow structures. With the POD method, the time-averaged flow field and the dominating modes are obtained. Based on the analysis of the POD modes, it is found that the induced vortex generated by the interaction between the leakage vortex and the endwall vortex has strong turbulence characteristics. Based on the entropy generation rates, viscous loss mechanism is further analyzed. It is found that the shear strain rates dominate the viscous dissipation losses, and the fluctuation dissipation has a strong local enhancement effect.

show abstract

Analysis of Different POD Processing Methods for SPIV-Measurements in Compressor Cascade Tip Leakage Flow

Cited by 14 publications

References 46 publications

Analysis of Tip Leakage Vortex Instability and Blade Force in a Low-Speed Compressor Cascade

Analysis of Tip Leakage Vortex Instability and Blade Force in a Low-Speed Compressor Cascade

Active Flow Control Based Bleed in an Axial Compressor Cascade Using Large Eddy Simulation

Analysis of the relationship between turbulence characteristics and loss mechanism in the tip leakage flow of turbine blade

Contact Info

Product

Resources

About