Curtis Stage Nozzle/Rotor Aerodynamic Interaction and the Effect on Stage Performance

Rashid, Stephen; Tremmel, Matthew; Waggott, J.; Moll, Randall

doi:10.1115/gt2006-91115

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…[2] showed a Curtis steam Turbine [3] presented ways of designing the Curtis stage, nozzle/rotor aerodynamic interaction and the effects on Curtis stage performance This paper for the first time presents eight variants with full and partial admission for the optimization of a Curtis stage in a 1 MW steam turbine.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Curtis stage in 1 MW steam turbine

Koprowski

Rządkowski

2019

E3S Web Conf.

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When operating at 3000 rpm, small turbines do not require a gear box and the generator does not require complex electronic software. This paper analyses the various geometries of the Curtis stage, comprising two rotor and stator blades with and without an outlet, from the efficiency point of view. Presented are 3D steady viscous flows. The results were compared with the performance of an axial turbine.

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Section: Introductionmentioning

confidence: 99%

Optimization of Curtis stage in 1 MW steam turbine

Koprowski

Rządkowski

2019

E3S Web Conf.

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“…Investigations of supersonic axial impulse turbines with axisymmetric nozzles and partial admission provided by Natalevich (1979) [3], Dorney et al (1999) [4], Tog and Tousi (2013) [5], Varma and Soundranayagam (2012) [6] show that efficiency of these turbines does not exceed 65%. Investigation of the Curtis stage with partial admission, which first row belongs to highly loaded class, provided by Rashid et al (2007) [7], showed that efficiency of such stages does not exceed 60%. Highly loaded transonic reaction cascades were investigated by Sonoda et al (2006) [8] and Wolf et al (2010) [9].…”

Section: Introductionmentioning

confidence: 99%

Design criteria for novel supersonic nozzles with high pitch-chord ratio

et al. 2018

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High pitch-chord ratio turbine stages are a novel class of high enthalpy drop impulse turbines. Significant limitation of traditional design approach for such turbines is a low partial admission rate due to low volumetric flow rates. The main idea of high pitch-chord ratio design is in increase of the stage load coefficient with decrease of the flow angles. The latter allows to provide higher partial admission rate and, hence, higher stage efficiency compared with the traditional design approach. As a consequence, efficiency of the high pitch-chord ratio stages varies between 65% and 75%, whereas partially admitted stages efficiency tend not to exceed 60%. High pitch-chord ratio nozzles have a rectangular cross section. This feature leads to a vortex pair occurrence in a nozzle flow path. An interaction of these vortices for transand supersonic stages leads to additional losses and comparably low nozzle efficiency. The present paper aimed at first, establishing the design criteria which are essential for the nozzle efficiency, and, second, finding the optimal ratios of the proposed criteria. CFD simulation approach is used for the study. The gained deliverables are helpful for increasing of the nozzle velocity ratio.

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“…In the industrial steam turbine field, hardly any literature reference can be found dealing with the kind of optimization of concern to the present work, namely highly loaded impulse type turbine stages. A relevant work for industrial steam turbine applications was published by Rashid et al (2007), mainly dealing with performance prediction variability of velocity compounded highly loaded Curtis stages, therefore focused on the supersonic aerodynamic interaction between nozzle and rotor. Conversely, other studies are available in the steam turbine literature where the methodological aspects and phenomena are similar to the present work, but the application deals with analysis and design of supersonic blade profiles used in last stages of large output steam turbines, see for instance the work of Váchová et al (2015).…”

Section: Introductionmentioning

confidence: 99%

Experimental And Numerical Analysis Of Supersonic Blade Profiles Developed For Highly Loaded Impulse Type Steam Turbine Stages

Ghio

Raffaeli

Sabattini³

et al. 2017

European Conference on Turbomachinery Fluid Dynamics and Hermodynamics

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The paper describes the results of a numerical and experimental research program addressing the aerodynamic investigation on the performance of blade profiles specifically developed for application in highly loaded impulse type turbine stages. The industrial requirements driving toward the adoption of highly loaded stage solutions are presented, along with an estimation of the profiles operating parameters. Two stator vanes and one rotor blade profile have been developed and extensively tested by means of flow field measurements and schlieren visualization in a transonic blow-down wind tunnel for linear cascades. Experimental results for the relevant operating conditions are presented, providing validation data for the CFD model used for blade design and evidencing that the main goals of the design optimization procedure have been achieved.

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Curtis Stage Nozzle/Rotor Aerodynamic Interaction and the Effect on Stage Performance

Cited by 4 publications

References 7 publications

Optimization of Curtis stage in 1 MW steam turbine

Optimization of Curtis stage in 1 MW steam turbine

Design criteria for novel supersonic nozzles with high pitch-chord ratio

Experimental And Numerical Analysis Of Supersonic Blade Profiles Developed For Highly Loaded Impulse Type Steam Turbine Stages

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