Numerical Investigation of Rotor-Stator Interaction in a High-Bypass Ratio Fan Stage

2013 ◽  
Author(s):  
Zhong Yang ◽  
Hengliang Wang ◽  
Jiachao Yan ◽  
Xiangyang Deng
Keyword(s):  
Transient Flow ◽  
Guide Vane ◽  
Field Investigation ◽  
Inlet Guide Vane ◽  
Unsteady Pressure ◽  
Pressure Distributions ◽  
Rotor Stator Interaction ◽  
Fan Blade ◽  
Transonic Fan ◽  
Bypass Ratio

Both steady and time-accurate simulations of the flow through a high-bypass ratio fan stage consisting of transonic fan rotor blade (FAN), outlet guide vane (OGV) of bypass duct, and inlet guide vane (IGV) of low-pressure compressor (LPC) are performed at design operating point to address the fundamental questions regarding the impacts of unsteady rotor-stator interactions. The original ratios of fan blade number to OGV and IGV vane numbers are scaled to avoid the full wheel computation, thus reducing the amount of time-accurate computation effort. The comparison between time-averaged unsteady results and steady results shows minor differences in the performance of bypass and core ducts. The transient flow field investigation shows that the unsteady interaction between FAN and IGV is much stronger than that in the bypass duct. Considering aerodynamic response and excitation mechanism due to rotor-stator interaction, the unsteady pressure distributions are examined. The time traces and frequency contents of the unsteady pressure show complex rotor-stator interaction arising from the incoming wakes and potential effects of downstream blade rows.

Effect of Clocking on the Unsteady Rotor Blade Loading in a 1.5-Stage Low-Speed Axial Compressor

2007 ◽  
Author(s):  
Huixia Jia ◽  
Konrad Vogeler
Keyword(s):  
Guide Vane ◽  
Pressure Fluctuations ◽  
Suction Side ◽  
Rotor Blades ◽  
Inlet Guide Vane ◽  
Mean Values ◽  
Design Point ◽  
Low Speed ◽  
Unsteady Pressure ◽  
Pressure Distributions

This paper presents the effect of clocking on the unsteady loading of the rotor blades in the first stage with an inlet guide vane row (IGV) of the Dresden Low-Speed Research Compressor (LSRC). The unsteady flow field of the Dresden LSRC at 10 IGV clocking positions for the design point was investigated using a 3D time-accurate viscous solver. The time-averaged pressure distributions on the pressure side (PS) and the suction side (SS) of the rotor blades at midspan (MS) are presented for different clocking positions. The effect of the clocking on the time-averaged Root Mean Square-value (RMS) of the unsteady pressure fluctuations of the rotor blades at MS is investigated. The unsteady pressure fluctuations on the PS and the SS of the rotor blades at MS for different clocking positions are presented and discussed. The unsteady blade pressure forces on the rotor blades, which are calculated from the profile pressure distributions, are presented and analysed for different clocking positions. The maximal fluctuation amplitude of the unsteady pressure forces on the rotor blades, which fluctuate around the nearly identical mean values for different clocking positions, can be reduced about 60 percent with the IGV clocking for the design point in the investigated configuration. The effect of the clocking on the time-resolved inlet- and outlet flow fields of the rotor blades is investigated and discussed.

1008 Investigation on Unsteady Pressure Fluctuation in Multi-stage Centrifugal Blower with Inlet Guide Vane

2014 ◽  
Vol 2014 (0) ◽  
pp. _1008-1_-_1008-4_
Author(s):  
Kiyotaka HIRADATE ◽  
Kiyohide SAKAMOTO ◽  
Yasushi SHINKAWA ◽  
Satoshi JOUKOU ◽  
Takeshi UCHIYAMA
Keyword(s):  
Pressure Fluctuation ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Centrifugal Blower ◽  
Unsteady Pressure ◽  
Multi Stage

scholarly journals Experimental Investigation of Rotor-Stator Interaction in Axial-Flow Turbines and Compressors

1998 ◽  
Vol 4 (4) ◽  
pp. 217-231
Author(s):  
Heinz E. Gallus
Keyword(s):  
Unsteady Flow ◽  
Total Pressure ◽  
Vector Fields ◽  
Guide Vane ◽  
Axial Flow ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Rotor Stator Interaction ◽  
Flow Compressor

Detailed results of unsteady flow measurements in a stator-rotor-stator assembly of an axial-flow turbine as well as an inlet guide vane-rotor-stator formation of an axial-flow compressor are presented in this paper.The measurements include the time-dependent 3-D velocity vector fields in the axial gaps between the blade rows by means of triple-hot wire-technique, furthermore the total pressure field downstream of the blade rows by means of semiconductor total pressure probes and the unsteady flow field determination in the rotor passages by LDV-technique. Special semiconductor pressure measurements along the casing all over the rotor tip clearance permit detailed discussion of the rotor tip clearance flows.The conclusion of the measured data provides a new and very instructive view of the physics of the unsteady blade-row interaction in axial-flow turbines and compressors.

scholarly journals Measurement of Unsteady Pressure Due to Rotor-Stator Interaction in Pump Guide Vane Passage.

1995 ◽  
Vol 61 (586) ◽  
pp. 2157-2164 ◽  
Author(s):  
Mitsuo Uno ◽  
Hiroshi Tsukamoto ◽  
Yuji Nagai ◽  
Hiroki Fukuno ◽  
Nobunari Hamafuku ◽  
...  
Keyword(s):  
Guide Vane ◽  
Unsteady Pressure ◽  
Rotor Stator Interaction

The action mechanism of rotor–stator interaction on the hydraulic and hydroacoustic characteristics of the guide vane in a jet centrifugal pump

2020 ◽  
Vol 34 (34) ◽  
pp. 2050396
Author(s):  
Rong Guo ◽  
Rennian Li ◽  
Renhui Zhang ◽  
Wei Han
Keyword(s):  
Flow Field ◽  
Transient Flow ◽  
Guide Vane ◽  
Centrifugal Pumps ◽  
Action Mechanism ◽  
Exterior Field ◽  
Outlet Angle ◽  
Rotor Stator Interaction ◽  
Wrap Angle ◽  
Hydrodynamic Noise

The aim of this study was to investigate the action mechanism of the rotor–stator interaction (RSI) in the transient flow field and hydrodynamic noise field of the guide vane in jet centrifugal pumps (JCPs). The numerical method of CFD (computational fluid dynamics), coupled with CFA (computational fluid acoustics), was used to analyze the correlation between the impeller parameters and the flow/sound characteristics of the guide vane. The results show that on the inlet surface of the guide vane, an impeller with fewer blades, a smaller wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for reducing the pressure fluctuation intensity. When the guide vane geometry is constant, the evolution processes of the transient flow field inside the static and dynamic cascades are mainly related to the blade number and speed of the impeller. An impeller with more blades, a larger wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for improving the flow field distribution in the dynamic and static cascades. The hydrodynamic noise in the interior field is mainly related to the fluctuation characteristics of the transient flow field, but that in the exterior field is related not only to the fluctuation characteristics of the transient flow field, but also to the structural properties of the JCP pump body. The hydrodynamic noise in the exterior field presents an obvious dipole symmetrical distribution on the meridional plane, and the minimum value appears in the direction of the rotation axis because of the symmetrical structural characteristics of the pump body. The modal-shaped features of the JCP lead to a sidelobe phenomenon on the sagittal plane.

Numerical analysis of hub cavity leakage

2019 ◽  
Vol 91 (8) ◽  
pp. 1086-1092
Author(s):  
Ye Xia ◽  
Yadong Xie ◽  
Danwang Li ◽  
Wenjie Wang
Keyword(s):  
Guide Vane ◽  
Suction Surface ◽  
Content Type ◽  
Tooth Structure ◽  
Aerodynamic Loss ◽  
Rotor Stator Interaction ◽  
Overall Performance ◽  
The Impact ◽  
Bypass Ratio ◽  
Practical Implications

Purpose This paper aims to predict the effect of the hub cavity leakage on the overall performance with numerical simulations in the fan/booster of a high bypass ratio turbofan engine. Design/methodology/approach Simulations are conducted for leakage at the fan, the outlet of guide vane and the three-stage booster, as well as hub leakage (contain cavities and sealing). The results obtained are compared to the corresponding simulations without hub leakage. Findings The rotor/stator interaction locations are evaluated to discover a better location. The results show that the seal tooth structure produces secondary flow and turbulence in the root of blade suction surface, which increases the aerodynamic loss. The sealing clearance should be controlled to shrink the turbulent region and decrease the leakage. Practical implications This work can provide a theoretical guidance and technical support for the compressor design, which avoid many repeated manufactures and reduce waste of resources. Originality/value This work improves the understanding of the impact mechanism of hub cavity leakage on the performance when the clearance size of seal is variable.

scholarly journals Aerodynamic and Aeroelastic Effects of Design-Based Geometry Variations on a Low-Pressure Compressor

2020 ◽  
Vol 5 (4) ◽  
pp. 26
Author(s):  
Torben Eggers ◽  
Hye Rim Kim ◽  
Simon Bittner ◽  
Jens Friedrichs ◽  
Joerg R. Seume
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Vibration Amplitude ◽  
Guide Vane ◽  
Total Pressure Loss ◽  
Inlet Guide Vane ◽  
Gap Size ◽  
Operating Points ◽  
Bypass Ratio ◽  
Pressure Compressor

In modern aircraft engines, the low-pressure compressor (LPC) is subjected to a flow characterized by strong wakes and secondary flows from the upstream fan. This concerns ultra-high bypass ratio (UHBR) turbofan engines, in particular. This paper presents the aerodynamic and aeroelastic sensitivities of parametric variations on the LPC, driven by the design considerations in the upstream fan. The goal of this investigation was to determine the influence of design-based geometry parameter variations on the LPC performance under realistic inlet flow distributions and the presence of an s-duct. Aerodynamic simulations are conducted at the design and off-design operating points with the fan outflow as the inlet boundary conditions. Based on the aerodynamic results, time-linearized unsteady simulations are conducted to evaluate the vibration amplitude at the resonance operating points. First, the bypass ratio is varied by reducing the channel height of the LPC. The LPC efficiency decreases by up to 1.7% due to the increase in blockage of the core flow. The forced response amplitude of the rotor decreases with increasing bypass ratio due to increased aerodynamic damping. Secondly, the fan cavity leakage flow is considered as it directly affects the near hub fan flow and thus the inflow of the LPC. This results in an increased total-pressure loss for the s-duct due to mixing losses. The additional mixing redistributes the flow at the s-duct exit leading to a total-pressure loss reduction of 4.3% in the first rotor at design point. This effect is altered at off-design conditions. The vibration amplitude at low speed resonance points is increased by 19% for the first torsion and 26% for second bending. Thirdly, sweep and lean are applied to the inlet guide vane (IGV) upstream of the LPC. Despite the s-duct and the variable inlet guide vane (VIGV) affecting the flow, the three-dimensional blade design achieves aerodynamic and aeroelastic improvements of rotor 1 at off-design. The total-pressure loss reduces by up to 18% and the resonance amplitude more than 10%. Only negligible improvements for rotor 1 are present at the design point. In a fourth step, the influence of axial gap size between the stator and the rotor rows in the LPC is examined in the range of small variations which shows no distinct aerodynamic and aeroelastic sensitivities. This finding not only supports previous studies, but it also suggests a correlation between mode shapes and locally increased excitaion with increasing axial gap size. As a result, potential design improvements in future fan-compressor design are suggested.

scholarly journals The Action Mechanism of Rotor–Stator Interaction on Hydraulic and Hydroacoustic Characteristics of a Jet Centrifugal Pump Impeller and Performance Improvement

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 465
Author(s):  
Guo ◽  
Li ◽  
Zhang ◽  
Han
Keyword(s):  
Flow Field ◽  
Pressure Fluctuation ◽  
Transient Flow ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Action Mechanism ◽  
Optimization Scheme ◽  
Fluctuation Intensity ◽  
Blade Number ◽  
Rotor Stator Interaction

The aim of this study was to investigate the action mechanism of the rotor–stator interaction (RSI) on the transient flow field and hydrodynamic noise field inside the impeller of jet centrifugal pumps (JCPs) and optimize effects of the guide vane on the hydraulic and hydroacoustic characteristics of the impeller. The numerical method of CFD (computational fluid dynamics) coupled with CFA (computational fluid acoustics) was used to analyze the correlation between the guide vane and the flow/sound performances of the impeller. The orthogonal test method, with the hydroacoustic performance of the impeller taken as the objective, was used to optimize the structural parameters of the guide vane for the stability of the hydraulic performance of the JCP. The results show that the RSI leads to a significant increase in the hydroacoustic level of the impeller, but it is indispensable for improving the hydraulic performance of the pump. The RSI effect on the fluctuation intensity of the transient flow field inside the impeller is much more sensitive than the time-average, and the fluctuation intensity of the flow field is positively correlated with the vortex intensity inside the impeller. When the impeller geometry is constant, the evolution processes of the flow field inside the impeller are mainly related to the blade number of the guide vane; when the number of guide vanes is given, the RSI effect on the hydroacoustic characteristic of the impeller is characterized by a positive correlation between the total sound pressure level (SPL) and the fluctuation intensity of the flow field. The frequency spectrum characteristics of the hydroacoustic SPL of the impeller are not consistent with the pressure fluctuation characteristics inside the impeller. The pressure fluctuation characteristics are related not only to the blade number and speed of the impeller but also to its wake characteristics determined by the guide vane. The optimization scheme for the stable hydraulic performance of the JCP significantly reduced the total SPL of the impeller compared with the original scheme, which verifies the feasibility of using the weight matrix optimization method to obtain the global optimization scheme.

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