Reconstructing Compressor Non-Uniform Circumferential Flow Field From Spatially Undersampled Data: Part 1 \u2014 Methodology and Sensitivity Analysis

Abstract The flow field in a compressor is circumferentially non-uniform due to the wakes from upstream stators, the potential field from both upstream and downstream stators, and blade row interactions. This non-uniform flow impacts stage performance as well as blade forced vibrations. Historically, experimental characterization of the circumferential flow variation is achieved by circumferentially traversing either a probe or the stator rows. This involves the design of complex traverse mechanisms and can be costly. To address this challenge, a novel method is proposed to reconstruct compressor nonuniform circumferential flow field using spatially under-sampled data points from a few probes at fixed circumferential locations. The paper is organized into two parts. In the present part of the paper, details of the multi-wavelet approximation for the reconstruction of circumferential flow and use of the Particle Swarm Optimization algorithm for selection of probe positions are presented. Validation of the method is performed using the total pressure field in a multi-stage compressor representative of small core compressors in aero engines. The circumferential total pressure field is reconstructed from 8 spatially distributed data points using a triple-wavelet approximation method. Results show good agreement between the reconstructed and the true total pressure fields. Also, a sensitivity analysis of the method is conducted to investigate the influence of probe spacing on the errors in the reconstructed signal.

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The Influence of Blade Lean on Straight and Annular Turbine Cascade Flow Field

Journal of Turbomachinery ◽

10.1115/1.4000536 ◽

2010 ◽

Vol 133 (1) ◽

Cited By ~ 9

Author(s):

Gabriele D’Ippolito ◽

Vincenzo Dossena ◽

Alessandro Mora

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Experimental Tests ◽

Phenomenological Approach ◽

Pressure Probe ◽

Steam Turbines ◽

Flow Angle ◽

Oil Flow ◽

Lean Angle ◽

Oil Flow Visualization

The work proposes a detailed description of the flow field throughout leaned turbine nozzles and reports a sensitivity analysis with respect to the lean angle. A phenomenological approach focuses the attention on pressure contours distribution on both inside and outside the passage. The study involves both straight and annular cascades mounting a typical intermediate reaction degree section, designed for steam turbines. Blades are built by stacking the same 2D profile along different linear axes, characterized by different angles with respect to the normal or radial direction: α=0 deg for prismatic blade and α=10 deg, 15 deg, and 20 deg for the leaned ones are considered. Experimental and numerical tests were performed at the nominal inlet flow angle in order to avoid any effect related to blade sweep. Experimental tests were carried out at the design outlet Mach number of 0.65; measurements were performed at the Laboratorio di Fluidodinamica delle Macchine of Politecnico di Milano. Only linear cascades with prismatic and 20 deg leaned blades were experimentally tested, providing data both downstream and inside the blade passage by means of pressure probe traversing, endwall pressure taps, and oil flow visualization. Experimental results were also used to validate the numerical setup, which provided a detailed computational picture of the flow field throughout the channel. The influence of the pressure contours’ shape on secondary vorticity activity downstream of the passage is highlighted and discussed, focusing the attention on secondary structures and loss distribution in this region. The resulting description of the flow field, based on the representation of pressure contours, supports the sensitivity analysis with respect to the blade lean angle, identifying the mechanism that leads the secondary vorticity to grow in regions where secondary losses and blade loading decrease.

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Adaptive Flow Field Thermal Modeling Techniques for Turbine Rotor-Stator Cavities

Volume 3C: Heat Transfer ◽

10.1115/gt2013-94845 ◽

2013 ◽

Author(s):

Jose Maria Rey Villazón ◽

Martin Berthold ◽

Arnold Kühhorn

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Boundary Conditions ◽

Thermal Modeling ◽

Turbine Rotor ◽

Special Focus ◽

Fe Model ◽

Preliminary Design ◽

Design Assessment ◽

The Impact

At preliminary design stages of the turbine discs design process, reducing uncertainty in the thermal prediction of critical parts models is decisive to bid a competitive technology in the aerospace industry. This paper describes a novel approach to develop adaptive thermal modeling methods for non-gaspath turbine components. The proposed techniques allow automated scaling of disc cavities during preliminary design assessment of turbine architectures. The research undertaken in this work begins with an overview of the past investigations on the flow field in cavities of the air system surrounding the turbine discs. A theoretical approach is followed to identify the impact of the design geometry and operation parameters of a simplistic rotor-stator cavity, with special focus on swirl and windage effects. Then, a parametric CFD process is set up to conduct sensitivity analysis of the flow field properties. The CFD sensitivity analysis confirmed the parameter influences concluded from the theoretical study. The findings from the CFD automated studies are used to enhance the boundary conditions of a thermal FE-model of an actual high pressure turbine. The new set of thermal boundary conditions adapts the flow field to changes in the cavity parameters. It was found that the deviation to experimental data of the traditional preliminary modeling technique is about 4 times higher as the deviation of the CFD-enhanced technique. When running the FE-model through a transient cycle, the results from the CFD-enhanced method are significantly closer to the test data than those from the traditional method, which suggests there is high potential for using these adaptive thermal techniques during turbine preliminary design stages.

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Numerical Sensitivity Analysis for Supercritical CO 2 Radial Turbine Performance and Flow Field

Energy Procedia ◽

10.1016/j.egypro.2017.09.233 ◽

2017 ◽

Vol 129 ◽

pp. 1117-1124 ◽

Cited By ~ 6

Author(s):

Alireza Ameli ◽

Antti Uusitalo ◽

Teemu Turunen-Saaresti ◽

Jari Backman

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Turbine Performance ◽

Radial Turbine

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Reconstructing Compressor Non-Uniform Circumferential Flow Field From Spatially Undersampled Data: Part 1 — Methodology and Sensitivity Analysis

Volume 2A: Turbomachinery ◽

10.1115/gt2020-14867 ◽

2020 ◽

Author(s):

Fangyuan Lou ◽

Nicole L. Key

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Total Pressure ◽

Pressure Field ◽

Sampled Data ◽

Wavelet Approximation ◽

Multi Stage ◽

Reconstructed Signal ◽

Data Points ◽

Aero Engines

Abstract The flow field in a compressor is circumferentially non-uniform due to the wakes from upstream stators, the potential field from both upstream and downstream stators, and blade row interactions. This non-uniform flow impacts stage performance as well as blade forced vibrations. Historically, experimental characterization of the circumferential flow variation is achieved by circumferentially traversing either a probe or the stator rows. This involves the design of complex traverse mechanisms and can be costly. To address this challenge, a novel method is proposed to reconstruct compressor nonuniform circumferential flow field using spatially under-sampled data points from a few probes at fixed circumferential locations. The paper is organized into two parts. In the present part of the paper, details of the multi-wavelet approximation for the reconstruction of circumferential flow and use of the Particle Swarm Optimization algorithm for selection of probe positions are presented. Validation of the method is performed using the total pressure field in a multi-stage compressor representative of small core compressors in aero engines. The circumferential total pressure field is reconstructed from 8 spatially distributed data points using a triple-wavelet approximation method. Results show good agreement between the reconstructed and the true total pressure fields. Also, a sensitivity analysis of the method is conducted to investigate the influence of probe spacing on the errors in the reconstructed signal.

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Effects of Squealer Tip Geometry Deviation on Flow Field and Aerodynamic Performance Using Uncertainty Quantification Method and Sensitivity Analysis Method

10.33737/gpps19-bj-203 ◽

2019 ◽

Author(s):

Wei Shi ◽

◽

Pingting Chen ◽

Xueying Li ◽

Jing Ren ◽

...

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Uncertainty Quantification ◽

Aerodynamic Performance ◽

Analysis Method ◽

Quantification Method ◽

Sensitivity Analysis Method ◽

Geometry Deviation

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Flow field simulation of supercritical carbon dioxide jet: Comparison and sensitivity analysis*

Journal of Hydrodynamics ◽

10.1016/s1001-6058(15)60474-7 ◽

2015 ◽

Vol 27 (2) ◽

pp. 210-215 ◽

Cited By ~ 25

Author(s):

Hai-zhu Wang ◽

Gen-sheng Li ◽

Shou-ceng Tian ◽

Yu-xiong Cheng ◽

Zhen-guo He ◽

...

Keyword(s):

Carbon Dioxide ◽

Sensitivity Analysis ◽

Supercritical Carbon Dioxide ◽

Flow Field ◽

Flow Field Simulation ◽

Field Simulation ◽

Supercritical Carbon

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The Influence of Blade Lean on Straight and Annular Turbine Cascade Flow Field

Volume 6: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2008-51199 ◽

2008 ◽

Cited By ~ 1

Author(s):

Gabriele D’Ippolito ◽

Vincenzo Dossena ◽

Alessandro Mora

Keyword(s):

Sensitivity Analysis ◽

Flow Field ◽

Experimental Tests ◽

Phenomenological Approach ◽

Pressure Probe ◽

Steam Turbines ◽

Flow Angle ◽

Oil Flow ◽

Lean Angle ◽

Set Up

The paper proposes a detailed description of the flow field throughout leaned turbine nozzles and reports a sensitivity analysis with respect to the lean angle. A phenomenological approach focuses the attention on pressure contours distribution both inside and outside the passage. The study involves both straight and annular cascades mounting a typical intermediate reaction degree section, designed for steam turbines. Blades are built by stacking the same 2-D profile along different linear axis, characterized by different angles with respect to the normal or radial direction: α = 0 deg for prismatic blade and α = 10, 15 and 20 deg for the leaned ones are considered. Experimental and numerical tests were performed at the nominal inlet flow angle in order to avoid any effect related to blade sweep. Experimental tests were carried out at the design outlet Mach number of 0.65; measurements were performed at the Laboratorio di Fluidodinamica delle Macchine (LFM) of Politecnico di Milano. Only linear cascades with prismatic and 20 deg leaned blades were experimentally tested providing data both downstream and inside the blade passage by means of pressure probe traversing, endwall pressure taps and oil flow visualization. Experimental results were also used to validate the numerical set-up, which provided a detailed computational picture of the flow field throughout the channel. The influence of pressure contours shape on secondary vorticity activity downstream of the passage is highlighted and discussed, focusing the attention on secondary structures and loss distribution in this region. The resulting description of the flow field, based on the representation of pressure contours, supports the sensitivity analysis with respect to the blade lean angle, identifying the mechanism that leads the secondary vorticity to grow in regions where secondary losses and blade loading decrease.

Download Full-text