Mach Number Effects on Turbine Blade Transition Length Prediction

Boyle, R. J.; Simon, F. F.

doi:10.1115/1.2836722

Cited by 20 publications

(7 citation statements)

References 26 publications

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“…Moreover, since the transition process is triggered around the shock region concurrently, an alternative reason of the temperature deviation for SST + γ-Reθ model may be that the start of full turbulent boundary layer (i.e., the end of the transition process) predicted by the γ-Reθ model is located upstream of the real one, partially due to the model's overlook of the compressible effects on the transition onset and length. The fact that the compressibility can defer the transition onset and increase its length has been realized by some researches (e.g., [30,31]), although complete experimental correlations as a function of Mach number haven't been established entirely. So both turbulence and transition models considering compressible effects are worth exploring in the future.…”

Section: Heat Transfer Featuresmentioning

confidence: 99%

The Application of Discontinuous Galerkin Methods in Conjugate Heat Transfer Simulations of Gas Turbines

Hao

Ren

2014

Energies

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Abstract:The performance of modern heavy-duty gas turbines is greatly determined by the accurate numerical predictions of thermal loading on the hot-end components. The purpose of this paper is: (1) to present an approach applying a novel numerical technique-the discontinuous Galerkin (DG) method-to conjugate heat transfer (CHT) simulations, develop the engineering-oriented numerical platform, and validate the feasibility of the methodology and tool preliminarily; and (2) to utilize the constructed platform to investigate the aerothermodynamic features of a typical transonic turbine vane with convection cooling. Fluid dynamic and solid heat conductive equations are discretized into explicit DG formulations. A centroid-expanded Taylor basis is adopted for various types of elements. The Bassi-Rebay method is used in the computation of gradients. A coupled strategy based on a data exchange process via numerical flux on interface quadrature points is simply devised. Additionally, various turbulence Reynolds-Averaged-Navier-Stokes (RANS) models and the local-variable-based transition model γ-Reθ are assimilated into the integral framework, combining sophisticated modelling with the innovative algorithm. Numerical tests exhibit good consistency between computational and analytical or experimental results, demonstrating that the presented approach and tool can handle well general CHT simulations. Application and analysis in the turbine vane, focusing on features around where OPEN ACCESSEnergies 2014, 7 7858 there in cluster exist shock, separation and transition, illustrate the effects of Bradshaw's shear stress limitation and separation-induced-transition modelling. The general overestimation of heat transfer intensity behind shock is conjectured to be associated with compressibility effects on transition modeling. This work presents an unconventional formulation in CHT problems and achieves its engineering applications in gas turbines.

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Section: Heat Transfer Featuresmentioning

confidence: 99%

The Application of Discontinuous Galerkin Methods in Conjugate Heat Transfer Simulations of Gas Turbines

Hao

Ren

2014

Energies

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“…6b). At rst glance, this contradicts the results of Narasimha [12] or Boyle and Simon [13]. They observed a delay of the onset of transition and a reduction of the turbulent spot production rate for increasing Mach numbers.…”

Section: Mach Number Effectmentioning

confidence: 74%

Effects of Reynolds and Mach numbers on the profile losses of a conventional low-pressure turbine rotor cascade with an increasing pitch-chord ratio

Coton

Arts

Lefebvre³

2001

Proceedings of the Institution of Mechanical Engineers, Part A:

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The evolution of the pressure loss coef cient and the exit ow angle has been investigated for a conventional low pressure turbine rotor blade of Snecma-Moteurs mounted in a stationary cascade arrangement at the von Karman Institute. As the boundary layers along those airfoils could exhibit laminar characteristics over a non-negligible distance, the pro le losses are directly linked to the occurrence of transition and separation. The main parameters affecting the boundary layer status are taken into account. The exit Reynolds and Mach numbers respectively range between 190 000 and 680 000 and between 0.6 and 0.9, the inlet free stream turbulence is 0.8 per cent. The pitch-chord ratio has also been varied from its nominal value. Although general tendencies for the loss coef cient variation with respect to each parameter have been found, it has been demonstrated that a better loss estimation needs to consider the conjunction of all these parameters. The present work also points out the weakness of the traditional correlation methods when the aerodynamic load of the blades is increased.

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“…C-type grids, typically 377 x 55, were used. Boyle and Simon [32] give a more detailed description of the analysis. The solutions were monitored to assure that convergence was achieved.…”

Section: Heat Transfer Modeling Assumptionsmentioning

confidence: 99%

“…The transition length model is the one detailed by Boyle and Simon [32]. It is a modification of the transition length model of Solomon et al [33] to account for Mach number effects.…”

Section: Heat Transfer Modeling Assumptionsmentioning

confidence: 99%

Simplified Approach to Predicting Rough Surface Transition

Boyle

Stripf

2009

Journal of Turbomachinery

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Turbine vane heat transfer predictions are given for smooth and rough vanes where the experimental data show transition moving forward on the vane as the surface roughness physical height increases. Consistent with smooth vane heat transfer, the transition moves forward for a fixed roughness height as the Reynolds number increases. Comparisons are presented with published experimental data. Some of the data are for a regular roughness geometry with a range of roughness heights, Reynolds numbers, and inlet turbulence intensities. The approach taken in this analysis is to treat the roughness in a statistical sense, consistent with what would be obtained from blades measured after exposure to actual engine environments. An approach is given to determine the equivalent sand grain roughness from the statistics of the regular geometry. This approach is guided by the experimental data. A roughness transition criterion is developed, and comparisons are made with experimental data over the entire range of experimental test conditions. Additional comparisons are made with experimental heat transfer data, where the roughness geometries are both regular and statistical. Using the developed analysis, heat transfer calculations are presented for the second stage vane of a high pressure turbine at hypothetical engine conditions.

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Mach Number Effects on Turbine Blade Transition Length Prediction

Cited by 20 publications

References 26 publications

The Application of Discontinuous Galerkin Methods in Conjugate Heat Transfer Simulations of Gas Turbines

The Application of Discontinuous Galerkin Methods in Conjugate Heat Transfer Simulations of Gas Turbines

Effects of Reynolds and Mach numbers on the profile losses of a conventional low-pressure turbine rotor cascade with an increasing pitch-chord ratio

Simplified Approach to Predicting Rough Surface Transition

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