The impact of rotor labyrinth seal leakage flow on the loss generation in an axial turbine

Anker, Jan E.; Mayer, Jürgen F.; Casey, Michael

doi:10.1243/095765005x31081

Cited by 12 publications

(6 citation statements)

References 22 publications

(23 reference 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: 99%

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: 99%

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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“…The yþ (of the closest grid point from wall) is around 2 in the blade and endwall surfaces. Anker et al 40,41 made a comparison of unsteady and steady simulations about the interactions of the leakage flow and the main flow in the shrouded turbine. The results have shown that it is perfectly sufficient to conduct steady-state simulations in order to capture the average rotor leakage flow effects.…”

Section: Numerical Techniquementioning

confidence: 99%

Comparative investigation of tip leakage flow and its effect on stage performance in shrouded and unshrouded turbines

Gao

Zheng

Zhang

et al. 2012

Proceedings of the Institution of Mechanical Engineers, Part G:

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In order to provide reference for the choice of the turbine architecture in specific application, comparative investigation was conducted to investigate the shrouded and unshrouded rotor tip leakage flows by means of the commercial CFX software, which modeled the flow in a 1.5-stage turbine. Tip leakage loss production mechanisms as well as the effects of tip clearance and pitch–chord ratio on tip leakage and stage performances were discussed and compared in this article. Numerical results show that, the leakage flow at the shroud cavity inlet effectively removes the boundary layer at rotor leading edge, and then reduces the casing secondary flows inside rotor passage. There is a break-even tip clearance at which both the shrouded and unshrouded turbines have the same efficiency, and if tip clearance is less than it, the unshrouded turbine performs better than the shrouded turbine. Compared to the unshrouded turbine, the shrouded turbine can reduce the sensitivity of turbine performances to changes in tip clearance. Moreover, at the given relative change in leakage flow, the relative change in work is approximately twice the relative change in efficiency. Besides, pitch–chord ratio has the different impact on the tip leakage mixing processes in shrouded and unshrouded turbines. It is effective to achieve lower tip leakage losses by turning the leakage flows to reduce mixing losses in shrouded turbines, and by blade tip design or tip clearance treatment to reduce the tip leakage flow in unshrouded turbines.

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“…The influence of the one-sided shroud seal composed of two disks on the flow in axial low-speed turbine passages has been analysed in [2,3]. Among other issues, these works examined experimentally the influence of the leakages on the mixing loss and secondary flows.…”

Section: Introductionmentioning

confidence: 99%