A New Alternative for Reduction of Secondary Flows in Low Pressure Turbines

Torre, Diego de la; ́zquez, Rau ́l Va; Blanco, Elena de la Rosa; Hodson, H. P.

doi:10.1115/gt2006-91002

Cited by 8 publications

(5 citation statements)

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“…Thus, helicity was introduced to discern the secondary flow vortex and study the flow field in the vane. The helicity is the scalar product of the vorticity vector and the velocity of flow, which is also used by Torre [18], Anker [19] and Natkaniec [20] in their study to analyze the complex flow field caused by the secondary flow. In order to understand the evolution of secondary flow vortex in the passage, contours of helicity and isolines of stagnation pressure recovery coefficient are showed in a set of cross section, which locate at 5% C x upstream of the blade leading edge, 30%, 60%, 90% and 120% downstream of the blade leading edge successively.…”

Section: Analysis Of Numerical Resultsmentioning

confidence: 98%

Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

Zou

Kong³

et al. 2016

International Journal of Turbo &Amp; Jet-Engines

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Supersonic turbine is widely used in the turbo pump of modern rocket. A preliminary design method for supersonic turbine has been developed considering the coupling effects of turbine and nozzle. Numerical simulation has been proceeded to validate the feasibility of the design method. As the strong shockwave reflected on the mixing plane, additional numerical simulated error would be produced by the mixing plane model in the steady CFD. So unsteady CFD is employed to investigate the aerodynamic performance of the turbine and flow field in passage. Results showed that the preliminary design method developed in this paper is suitable for designing supersonic turbine. This periodical variation of complex shockwave system influences the development of secondary flow, wake and shock-boundary layer interaction, which obviously affect the secondary loss in vane passage. The periodical variation also influences the strength of reflecting shockwave, which affects the profile loss in vane passage. Besides, high circumferential velocity at vane outlet and short blade lead to high radial pressure gradient, which makes the low kinetic energy fluid moves towards hub region and produces additional loss.

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Section: Analysis Of Numerical Resultsmentioning

confidence: 98%

Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

Zou

Kong³

et al. 2016

International Journal of Turbo &Amp; Jet-Engines

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“…Torre et al [24] generated their endwall geometry by adding perturbations to the planar surface defined through a three-term Fourier series. The perturbations were specified at six axial locations.…”

Section: Review Of Endwall Studiesmentioning

confidence: 99%

A Geometry Generation Framework for Contoured Endwalls

Wood

Jones

Pountney

et al. 2019

Journal of Engineering for Gas Turbines and Power

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The mainstream, or primary, flow in a gas turbine annulus is characteristically two-dimensional over the midspan region of the blading, where the radial flow is almost negligible. Contrastingly, the flow in the endwall and tip regions of the blading is highly three-dimensional (3D), characterized by boundary layer effects, secondary flow features, and interaction with cooling flows. Engine designers employ geometric contouring of the endwall region in order to reduce secondary flow effects and subsequently minimize their contribution to aerodynamic loss. Such is the geometric variation of vane and blade profiles—which has become a proprietary art form—the specification of an effective endwall geometry is equally unique to each blade row. Endwall design methods, which are often directly coupled to aerodynamic optimizers, are widely developed to assist with the generation of contoured surfaces. Most of these construction methods are limited to the blade row under investigation, while few demonstrate the controllability required to offer a universal platform for endwall design. This paper presents a geometry generation framework (GGF) for the generation of contoured endwalls. The framework employs an adaptable meshing strategy, capable of being applied to any vane or blade, and a versatile function-based approach to defining the endwall shape. The flexibility of this novel approach is demonstrated by recreating a selection of endwalls from the literature, which were selected for their wide range of contouring approaches.

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“…The profile extended from 25% axial chord upstream to 75% downstream of airfoil leading edge. Experimental results showed an achievement of 72% reduction in SKEH (defined as SKEH = Secondary Kinetic Energy · Helicity, where Helicity = ω · V ) and 20% in mixed-out losses as defined in [8]. The cross-passage vortex was weakened.…”

Section: Introductionmentioning

confidence: 96%

“…An alternative nonaxisymmetric endwall profiling was suggested by Torre et al [8]. In that study, besides the modulation of cross-passage flow, they tried to control the formation mechanisms of horseshoe vortex.…”

Section: Introductionmentioning

confidence: 99%

A Nonaxisymmetric Endwall Design Methodology for Turbine Nozzle Guide Vanes and its Computational Fluid Dynamics Evaluation

Turgut

Camcı

2011

Volume 1: Advances in Aerospace Technology; Energy Water Nexus; Globalization of Engineering; Posters

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Nonaxisymmetric endwall contouring has recently become one of the ways to minimize the secondary flow related losses in a turbine nozzle guide vane (NGV) passage. In this study, a specific nonaxisymmetric endwall contouring design methodology is introduced. Fourier series based splines at different axial locations are generated and combined with the help of stream-wise B-splines within solid modeling program. Eight different contoured endwalls are presented in this paper. Computational study of these designs are performed by the finite-volume flow solver. The SST k–ω turbulence model is selected and a body-fitted structured grid is used. Total pressure distribution at the NGV exit shows that contouring the endwall effectively changes the results. Among from these various designs, the most promising one is with the contouring extended in the upstream of the vane leading edge. Mass-averaged value of 3.2% total pressure loss reduction is achieved at the NGV exit plane. The current study was performed in a rotating turbine rig simulating a state of the art HP turbine stage. An NGV only simulation is performed. This approach is helpful in isolating rotor-stator influence and the possible upstream flow modifications of the rim seal cavity flow existing in the rotating turbine research rig. The investigation including the rotor-stator interaction and rim seal cavity flow is the topic of a subsequent paper currently under progress.

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A New Alternative for Reduction of Secondary Flows in Low Pressure Turbines

Cited by 8 publications

References 0 publications

Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

A Geometry Generation Framework for Contoured Endwalls

A Nonaxisymmetric Endwall Design Methodology for Turbine Nozzle Guide Vanes and its Computational Fluid Dynamics Evaluation

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