Boundary Layer and Loss Measurements on the Rotor of an Axial-Flow Turbine

Hodson, H. P.

doi:10.1115/1.3239576

Cited by 59 publications

(30 citation statements)

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“…It is possible to calibrate hot films, but this is a difficult and time consuming process see Hodson [15] and Davies and O'Donnell [16]. Also, errors of 20% or more arise when hot films calibrated in a laminar flow are used to measure a turbulent flow.…”

Section: Methodsmentioning

confidence: 98%

Boundary Layer Development in the BR710 and BR715 LP Turbines—The Implementation of High-Lift and Ultra-High-Lift Concepts

Howell

Hodson

Schulte

et al. 2002

Journal of Turbomachinery

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This paper describes a detailed study into the unsteady boundary layer behaviour in two high lift and one ultra high lift Rolls-Royce Deutschland LP turbines. The objectives of the paper are to show that high lift and ultra high-lift concepts have been successfully incorporated into the design of these new LP turbine profiles.Measurements from surface mounted hot film sensors were made in full size, cold flow test rigs at the altitude test facility at Stuttgart University. The LP turbine blade profiles are thought to be state of the art in terms of their lift and design philosophy. The two high lift profiles represent slightly different styles of velocity distribution. The first high-lift profile comes from a two stage LP turbine (the BR710 cold-flow, high-lift demonstrator rig). The second high-lift profile tested is from a three-stage machine (the BR715 LPT rig). The ultra-high lift profile measurements come from a redesign of the BR715 LP turbine: this is designated the BR715UHL LP turbine. This ultra high-lift profile represents a 12% reduction in blade numbers compared to the original BR715 turbine.The results from NGV2 on all of the turbines show "classical" unsteady boundary layer behaviour. The measurements from NGV3 (of both the BR715 and BR715UHL turbines) are more complicated, but can still be broken down into classical regions of wake-induced transition, natural transition and calming. The wakes from both upstream rotors and NGVs interact in a complicated manner, affecting the suction surface boundary layer of NGV3. This has important implications for the prediction of the flows on blade rows in multistage environments.

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Section: Methodsmentioning

confidence: 98%

Boundary Layer Development in the BR710 and BR715 LP Turbines—The Implementation of High-Lift and Ultra-High-Lift Concepts

Howell

Hodson

Schulte

et al. 2002

Journal of Turbomachinery

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“…Evans (1978) carried out a similar study but, because the effect of wakes was not separated from the three-dimensional flow influence, the results were not conclusive. Work on a turbine rotor by Hodson (1984) had shown the significant impact of wakes on the increase of profile loss compared with that in a no-wake flow. More understanding of the wake interaction with a laminar boundary layer has been gained by the results obtained in the experimental work of Pfeil, et al (1983) on a flat plate and Doorly and Oldfield (1986) on a turbine blade.…”

Section: Introductionmentioning

confidence: 97%

“…A phase-locked data-logging technique was used and 100 samples were used to derive ensemble-averaged quantities; it was found that there was little improvement in using more samples. The data acquisition facilities and the techniques were similar to those used by Hodson (1984) and were described in detail by Dong (1988).…”

Section: Introductionmentioning

confidence: 99%

Compressor Blade Boundary Layers: Part 1—Test Facility and Measurements With No Incident Wakes

Yan¹,

Cumpsty

1990

Journal of Turbomachinery

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The boundary layers on compressor blades are sensitive to the conditions at which transition occurs and transition can be affected by the convection of wakes from upstream blade rows. This paper and its companion, Part 2 by the same authors, describes an experiment to study the effect of the moving wakes on the boundary layer of a compressor blade. This paper describes the background and facility devised to introduce wakes together with results obtained on the blades in tests without the wakes present. Part 2 describes the measurements made with the wakes present and presents conclusions for the whole project. Further details of all aspects of the work can be found in Dong {1988).

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“…The interactions have been studied using turbomachines 4 and simulations. 5 Much of this research has concluded that the most significant effect is the periodic forcing of the transition of the blade surface boundary layers and the influence this has upon the aerodynamic and thermodynamic performance of the blade row.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Interactions in the Rotor of an Axial Turbine

Hodson

Banieghbal

Dailey

1995

Journal of Propulsion and Power

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This article presents a study of the development of the three-dimensional flowfield within the rotor blades of a low-speed, large-scale axial flow turbine. Measurements have been performed in the rotating and stationary frames of reference. Time-mean data have been obtained using miniature five-hole pneumatic probes, whereas the unsteady development of the flow has been determined using three-axis subminiature hot-wire anemometers. Additional information is provided by the results of blade-surface flow-visualization experiments and surfacemounted hot-film anemometers. The development of the stator exit flow, as it passes through the rotor blades, is described. Unsteady data suggest that the presence of the rotor secondary and tip leakage flows restricts the region of unsteady interaction to near midspan when the stator wakes and secondary flows are adjacent to the suction surface. Surface-mounted hot-film data show that this affects the suction-side laminar-turbulent transition process. Nomenclature C v = axial chord E = anemometer voltage E () = anemometer voltage under zero-flow conditions H = boundary-layer shape factor 8*19 P () = stagnation pressure Re = Reynolds number s = surface distance s* = fractional surface distance, s/s m . M T,, = intensity of random velocity fluctuations, rms/F re , t = time measured from once-per-revolution trigger t* = fractional time, tlr U m = mean blade velocity V = velocity V rcf = stator midspan mean exit velocity 8* = boundary-layer displacement thickness 0 = boundary-layer momentum thickness p = density T = periodic time r u . = wall shear stress, (E 2 IE^ -I) 3 , arbitrary units a) = stagnation pressure loss coefficient, AP () /ipV 2 ef = time-mean {( )} = ensemble-variance of ... ( ) = ensemble-mean of ...

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Boundary Layer and Loss Measurements on the Rotor of an Axial-Flow Turbine

Cited by 59 publications

References 0 publications

Boundary Layer Development in the BR710 and BR715 LP Turbines—The Implementation of High-Lift and Ultra-High-Lift Concepts

Boundary Layer Development in the BR710 and BR715 LP Turbines—The Implementation of High-Lift and Ultra-High-Lift Concepts

Compressor Blade Boundary Layers: Part 1—Test Facility and Measurements With No Incident Wakes

Three-Dimensional Interactions in the Rotor of an Axial Turbine

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