• Title/Summary/Keyword: Rotor-Stator

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Study on Unsteady Pressure due to Fan Rotor-Stator Interaction

  • Goto, S.;Kodama, H.;Tsuchiya, N.;Nakamura, Y.;Nozaki, O.;Nishizawa, T.;Yamamoto, K.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.472-478
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    • 2004
  • This paper describes the characteristics of the unsteady pressure on the stator surface induced by rotor viscous wakes. The primary object of this study is to investigate the effects of axial spacing between the rotor and the stator and three-dimensional vane geometries such as stator sweep and stator lean on the unsteady pressure fluctuations on the stator vane. To predict these fluctuations, unsteady three-dimensional Navier-Stokes analyses are performed. Furthermore, a three-dimensional analytical method using unsteady lifting-surface theory is also used to elucidate the mechanism of interaction of passing rotor wakes with downstream stator. Five different fan configurations with three sets of stator geometries, which are three radial stator configurations with different axial spacing, the swept stator and the swept and leaned stator, are used for this study. It is found that, in axial spacing between rotor and stator, the effect of radial phase skew of incoming rotor wake is important for the reduction of the induced unsteady pressure in addition to the rotor wake decay. It is also shown that incorporation of stator sweep and lean is effective to reduce this unsteady pressure.

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A Study of rotor-stator interaction in an axial fan (축류송풍기의 동익과 정익 사이 간격변화에 따른 유동간섭에 관한 연구)

  • Rim, In-Won;Seon, Ho-Su;Joo, Won-Gu;Cho, Kang-Rae
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.819-824
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    • 2000
  • The flow inside an axial turbomachinery must be unsteady. Rotor-stator interaction by two blade rows influences performance, the generation of noise and vibration. So, it will be necessary to study the rotor-stator interaction for the design of an axial fan in which the axial gap between two blade rows is small. In this study, rotor-stator interaction is investigated by experimental methods. The research fan has one stage which consists of 24 rotor blades and 22 stator blades. Three-dimensional velocities measured using $45^{\circ}$ slanted hot wire probe and total pressure is measured using Kiel total pressure probe between rotor and stator with the axial 25%, 55%, 145% of chord length,. This study describes the influence of rotor-stator gap on the flow pattern, performance and loss. The efficiency curve show that the change of the rotor-stator gap make difference in the efficiency. And, the 3-dimensional velocity distribution show that the potential interaction between the rotor and the stator have a great effect on the flow field downstream of rotor, where there are wake flow. various vortices in hub region and leakage vortex in casing region etc.

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Numerical Analysis of a Turbine Rotor Cascade with Unsteady Passing Wakes (비정상 후류를 지나는 터빈 동익 주위의 유동장 수치해석)

  • Lee, Eun-Seok
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.153-156
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    • 2006
  • A turbine stage consists of a stator and rotor. A stator provides the required inlet flow conditions so that a rotor can produce the necessary power. Passing wakes generated at the trailing edge of a stator make an interaction with a rotor. In the present study, this interaction flow mechanism is investigated using the numerical analysis. In case of the large gap distance between the stator and rotor, the stator and rotor flow analysis can be separated. First, only the stator flow field is solved. Second, the rotor flow field is solved including the passing wake information from the stator analysis. The passing wake experiences the shearing as it approaches to the rotor leading edge. And it is chopped when it strikes the rotor body. After that, the chopped wakes becomes the prolongation as it goes downstream. Also, the aerodynamic characteristics with the variation of the gap distance between a stator and rotor was investigated. Pressure jumps due to the passing wakes result in the pressure and lift loss and it gets stronger with the closer gap distance. This unsteady effect proves to be directly related to the fatigue and noise in turbomachinery and this study would be helpful to investigate such fields.

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Simplified Rotor and Stator Resistance Estimation Method Based on Direct Rotor Flux Identification

  • Wang, Mingyu;Wang, Dafang;Dong, Guanglin;Wei, Hui;Liang, Xiu;Xu, Zexu
    • Journal of Power Electronics
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    • v.19 no.3
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    • pp.751-760
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    • 2019
  • Since parameter mismatch seriously impacts the efficiency and stability of induction motor drives, it is important to accurately estimate the rotor and stator resistance. This paper introduces a method to directly calculate the rotor flux that is independent of stator and rotor resistance and electrical angle. It is based on obtaining the rotor and stator resistance using the model reference adaptive system (MRAS) method. The method has a lower computation burden and less adaptation time when compared with other rotor resistance estimation methods. This paper builds three coordinate frames to analyze the rotor flux error and rotor resistance error. A number of implementation issues are also considered.

Study on the Parameter Identification for Induction Motors (유도 전동기 파라미터 추정에 관한 연구)

  • 김규식
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.199-202
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    • 2000
  • The accurate identification of the motor parameters in crucially important to achieve high dynamic performance of induction motors. In this paper parameter auto-tuning algorithms for stator(rotor) resistance stator(rotor) leakage inductance mutual inductance and rotor inertia. Stator(rotor) resistance and stator(rotor) leakage inductance are identified based on the stationary coordinate and mutual inductance and rotor resistor on the scalar speed control and the transient motor terminal voltage. To demonstrate the practical significance of our results we present some experimented results.

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Two-Dimensional Flow Behavior Through a Stage of an Axial Compressor (축류 압축기내의 2차원 유동 특성)

  • Hong, Seong-Hun;Baek, Je-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.8
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    • pp.2561-2571
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    • 1996
  • The flow in the turbomachinery is very unsteady due to the stator-rotor interaction. It has been indicated that the stator-rotor interaction has three distinct causes of unsteadiness: that is, the viscous vortex shedding, wake rotor interaction and potential stator-rotor interaction. In this paper, the mechanism of unsteady potential interaction and wake interaction in the stator-rotor stage flow is numerically investigated in two-dimensional view point. The numerical technique used is the upwind scheme of Van Leer's Flux Vector Splitting(FVS) and cubic spline interpolation is applied on zonal interface. Then, the flow field of a compressor stage composed of NACA 65410 is analyzed. Flow fields are found to be simulated reasonably by this method and the sensitivity due to back-pressure variation is more stronger than rotor-velocity variation.

Development of a Computational Method of 3-D Unsteady Incompressible Flow in Turbomachinery (터보기계내의 3차원 비정상 비압축성 유동계산방법의 개발)

  • Kim, Bbong-Kyun;Park, Jae-In;Joo, Won-Gu;Cho, Kang-Rae
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.2 s.3
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    • pp.57-63
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    • 1999
  • The flow through multistage turbomachinery is affected by the interaction between a rotor and a stator. The interaction is due to the inviscid potential effect and viscous effect between closely spaced rotor and stator airfoils. Three-dimensional, unsteady, incompressible Navier-Stokes equations with a standard $k-{\epsilon}$ model are solved using a non-staggered grid system. This method is applied to the flow through a multistage compressor measured by Stauter et al. The results have shown strong interaction between the rotating and stationary flow field. The decay of rotor wake and the pressure profiles agree very well with experimental data. The wake produced by rotor causes unsteady pressure on the surface of a stator. The rotor/stator interaction produces the unsteady pressure force on the rotor and stator blades.

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Experimental Investigation on Separated Flows of Axial Flow Stator and Diagonal Flow Rotor

  • Kinoue, Yoichi;Shiomi, Norimasa;Setoguchi, Toshiaki;Jin, Yingzi
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.3
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    • pp.223-231
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    • 2009
  • Experimental investigations were conducted for the internal flows of the axial flow stator and diagonal flow rotor. Corner separation near the hub surface and the suction surface of stator blade are mainly focused on. For the design flow rate, the values of the axial velocity and the total pressure at stator outlet decrease between near the suction surface and near the hub surface by the influence of corner wall. For the flow rate of 80-90% of the design flow rate, the corner separation of the stator between the suction surface and the hub surface is observed, which becomes widely spread for 80% of the design flow rate. At rotor outlet for 81% of the design flow rate, the low axial velocity region grows between near the suction surface of rotor and the casing surface because of the tip leakage flow of the rotor.

Numerical Simulation of Cascade Flows with Rotor-Stator Interaction Using the Multiblocked Grid (중첩 격자계를 이용한 동익과 정익의 상호작용이 있는 익렬 유동해석)

  • Jung, Y. R.;Park, W. G.;Lee, S. W.
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.163-169
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    • 1999
  • The numerical procedure has been developed for simulating incompressible viscous flow around a turbine stage with rotor-stator interaction. This study solves 2-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system. The Marker-and-Cell concept is applied to efficiently solve continuity equation. To impose an accurate boundary condition, O-H multiblocked grid system is generated. O-type grid and H-type grid is generated near and outer rotor-stator The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. Turbulent flows have been modeled by the Baldwin- Lomax turbulent model. To validate present procedure, the time averaged pressure coefficients around the rotor and stator are compared with experiment and a good agreement obtained.

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Numerical Analysis on the Effect of High-Shear in a Rotor-Stator Mixer (Rotor-Stator Mixer 전단효과에 관한 수치 해석적 연구)

  • Yeum, Sang Hoon;Lee, Seok Soon
    • Journal of Aerospace System Engineering
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    • v.13 no.5
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    • pp.39-48
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    • 2019
  • The turbulent flow in the rotor-stator mixer is based on shear characteristics generated by the interaction of the stator with the rotor rotating at high speed. In this study, the flow characteristics analysis of the unsteady state generated by the interaction of the rotor and the stator in the prototype model of the emulsion-fuel related mixer development was performed with the MRF and SMM by applying the ANSYS FLUENT $k-{\varepsilon}$ (RKE) turbulence model. The behavior and shear characteristics of the flow particles generated at the interface between the designed rotor and stator, and trends such as velocity distribution and turbulence eddy dissipation, were predicted and verified using the CFD analysis.