Prediction of Film Cooling Effectiveness and Heat Transfer due to Streamwise and Compound Angle Injection on Flat Surfaces

Neelakantan, S.; Crawford, Michael E.

doi:10.1115/95-gt-151

Cited by 4 publications

(1 citation statement)

References 8 publications

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“…They are compared to results from the heat transfer design system code, Texstan. Texstan is a boundary layer code (Neelakantan and Crawford, 1995), that accounts for the film cooling effect in a laterally averaged sense for boundary layers on curved walls. As can be seen from the figure, agreement between the measurements and predictions is excellent and confirms the accuracy of the code.…”

Section: Lp Blade (Vki)mentioning

confidence: 99%

The GT24/26 Low Pressure Turbine

Jennions

Sommer

Aigner

1998

Volume 1: Turbomachinery

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The GT24 and GT26 are the latest in a series of gas turbines from ABB. The GT24 is a 60 Hz, 183 MW turbine, while the GT26 is its (scaled) 50 Hz equivalent, producing 265 MW. They feature a 22 stage controlled diffusion aerofoil compressor, two combustors separated by a single stage high pressure turbine with a four stage low pressure (LP) turbine following the second combustor. This arrangement permits very high efficiencies while avoiding high temperatures and the need to use new, expensive materials. The first GT24 was delivered to Jersey Central Power and Light, Gilbert, New Jersey, USA, at the end of 1995 and achieved baseload operation in May 1996. The engine was highly instrumented with some 1200 measurement points to evaluate component performance. Subsequently, a through-flow datamatch to the design point data was made for the LP turbine and is compared to a full 3D multistage analysis in this paper. The 3D analysis accounts for all the cooling and leakage flows that enter the turbine flowpath and maintains a steady flow calculation by means of interface planes between each blade row that remove any circumferential non-uniformity from the computational flow field. To complement this aerodynamic analysis, some heat transfer results from the ABB GT26 test facility in Birr, Switzerland are also shown. The paper demonstrates how component technology for the first stage was verified at four universities and research centers concurrently with the design process. This experimental data supplemented the existing databases and engendered confidence in the overall aero/thermal design approach.

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Section: Lp Blade (Vki)mentioning

confidence: 99%

The GT24/26 Low Pressure Turbine

Jennions

Sommer

Aigner

1998

Volume 1: Turbomachinery

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Convective Heat Transfer and Aerodynamics in Axial Flow Turbines

Dunn

2001

Journal of Turbomachinery

112

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The primary focus of this paper is convective heat transfer in axial flow turbines. Research activity involving heat transfer generally separates into two related areas: predictions and measurements. The problems associated with predicting heat transfer are coupled with turbine aerodynamics because proper prediction of vane and blade surface-pressure distribution is essential for predicting the corresponding heat transfer distribution. The experimental community has advanced to the point where time-averaged and time-resolved three-dimensional heat transfer data for the vanes and blades are obtained routinely by those operating full-stage rotating turbines. However, there are relatively few CFD codes capable of generating three-dimensional predictions of the heat transfer distribution, and where these codes have been applied the results suggest that additional work is required. This paper outlines the progression of work done by the heat transfer community over the last several decades as both the measurements and the predictions have improved to current levels. To frame the problem properly, the paper reviews the influence of turbine aerodynamics on heat transfer predictions. This includes a discussion of time-resolved surface-pressure measurements with predictions and the data involved in forcing function measurements. The ability of existing two-dimensional and three-dimensional Navier–Stokes codes to predict the proper trends of the time-averaged and unsteady pressure field for full-stage rotating turbines is demonstrated. Most of the codes do a reasonably good job of predicting the surface-pressure data at vane and blade midspan, but not as well near the hub or the tip region for the blade. In addition, the ability of the codes to predict surface-pressure distribution is significantly better than the corresponding heat transfer distributions. Heat transfer codes are validated against measurements of one type or another. Sometimes the measurements are performed using full rotating rigs, and other times a much simpler geometry is used. In either case, it is important to review the measurement techniques currently used. Heat transfer predictions for engine turbines are very difficult because the boundary conditions are not well known. The conditions at the exit of the combustor are generally not well known and a section of this paper discusses that problem. The majority of the discussion is devoted to external heat transfer with and without cooling, turbulence effects, and internal cooling. As the design community increases the thrust-to-weight ratio and the turbine inlet temperature, there remain many turbine-related heat transfer issues. Included are film cooling modeling, definition of combustor exit conditions, understanding of blade tip distress, definition of hot streak migration, component fatigue, loss mechanisms in the low turbine, and many others. Several suggestions are given herein for research and development areas for which there is potentially high payoff to the industry with relatively small risk.

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Aerodynamic and Heat Flux Measurements in a Single-Stage Fully Cooled Turbine—Part I: Experimental Approach

Haldeman

Mathison

Dunn

et al. 2008

Journal of Turbomachinery

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This paper describes the experimental approach utilized to perform experiments using a fully cooled rotating turbine stage to obtain film effectiveness measurements. Significant changes to the previous experimental apparatus were implemented to meet the experimental objectives. The modifications include the development of a synchronized blowdown facility to provide cooling gas to the turbine stage, installation of a heat exchanger capable of generating a uniform or patterned inlet temperature profile, novel utilization of temperature and pressure instrumentation, and development of robust double-sided heat flux gauges. With these modifications, time-averaged and time-accurate measurements of temperature, pressure, surface heat flux, and film effectiveness can be made over a wide range of operational parameters, duplicating the nondimensional parameters necessary to simulate engine conditions. Data from low Reynolds number experiments are presented to demonstrate that all appropriate scaling parameters can be satisfied and that the new components have operated correctly. Along with airfoil surface heat transfer and pressure data, temperature and pressure data from inside the coolant plenums of the vane and rotating blade airfoils are presented. Pressure measurements obtained inside the vane and blade plenum chambers illustrate passing of the wakes and shocks as a result of vane/blade interaction. Part II of this paper (Haldeman, C. W., Mathison, R. M., Dunn, M. G., Southworth, S. A., Harral, J. W., and Heltland, G., 2008, ASME J. Turbomach., 130(2), p. 021016) presents data from the low Reynolds number cooling experiments and compares these measurements to CFD predictions generated using the Numeca FINE/Turbo package at multiple spans on the vanes and blades.

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Prediction of Film Cooling Effectiveness and Heat Transfer due to Streamwise and Compound Angle Injection on Flat Surfaces

Cited by 4 publications

References 8 publications

The GT24/26 Low Pressure Turbine

The GT24/26 Low Pressure Turbine

Convective Heat Transfer and Aerodynamics in Axial Flow Turbines

Aerodynamic and Heat Flux Measurements in a Single-Stage Fully Cooled Turbine—Part I: Experimental Approach

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