Reynolds Stress Transport Modeling of Film Cooling at the Leading Edge of a Symmetrical Turbine Blade Model

Nemdili, Fadéla; Azzi, Abbès; Theodoridis, Georgios; Jubran, B. A.

doi:10.1080/01457630802186064

Cited by 24 publications

(5 citation statements)

References 18 publications

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“…Note that the convection and production terms are exact, while the remaining terms have to be modeled [27]. Detailed derivations for the closure equations can be found in references [28][29][30][31][32], among others.…”

Section: Rsm Modelmentioning

confidence: 99%

Comparative Investigation on Heated Swirling Jets Using Experimental and Numerical Computations

Khelil

Naji

Braikia

et al. 2014

Heat Transfer Engineering

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The purpose of this paper is to investigate both experimentally and numerically the influence of various parameters on the different blowing configurations of multiple swirling jets. Flow rate was adjusted at Reynolds numbers ranging from 10 4 to 3 × 10 4 . The current study is carried out under uniform heat flux condition for each diffuser, at Reynolds number of 3 × 10 4 , with air being the working fluid. Experiments concerning the fusion of several jets show that the resulting jet is clearly more homogenized under swirling influence. Afterward, numerical simulation is also carried out using the finite-volume computational fluid dynamics solver FLUENT 6.3, in which the standard k − ε and the Reynolds stress turbulence model (RSM) were used for turbulence computations. The findings of this study show that the diffuser vane angle and a balance and an imbalance in temperature between the central and peripheral jets affect the quality of the thermal homogenization of the ambiance. Overall predictions obtained with the RSM model are in better agreement with the experimental data compared to those of the standard k − ε model.

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Section: Rsm Modelmentioning

confidence: 99%

Comparative Investigation on Heated Swirling Jets Using Experimental and Numerical Computations

Khelil

Naji

Braikia

et al. 2014

Heat Transfer Engineering

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“…The eddy viscosity hypothesis has been overcome in different ways. For the lowest BR of 0.3, Nemdili et al [21] obtained quite accurate predictions of the laterally averaged effectiveness in the showerhead region of a symmetric airfoil by using a second order Reynolds Stress model, which solves a transport equation for each stress component. However, the cases at higher BR were not satisfactorily captured.…”

Section: Ravellimentioning

confidence: 99%

Comparison of RANS and Detached Eddy Simulation Modeling Against Measurements of Leading Edge Film Cooling on a First-Stage Vane

Ravelli

Barigozzi

2017

Journal of Turbomachinery

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The performance of a showerhead arrangement of film cooling in the leading edge region of a first-stage nozzle guide vane was experimentally and numerically evaluated. A six-vane linear cascade was tested at an isentropic exit Mach number of Ma2s = 0.42, with a high inlet turbulence intensity level of 9%. The showerhead cooling scheme consists of four staggered rows of cylindrical holes evenly distributed around the stagnation line, angled at 45 deg toward the tip. The blowing ratios tested are BR = 2.0, 3.0, and 4.0. Adiabatic film cooling effectiveness distributions on the vane surface around the leading edge region were measured by means of thermochromic liquid crystals (TLC) technique. Since the experimental contours of adiabatic effectiveness showed that there is no periodicity across the span, the computational fluid dynamics (CFD) calculations were conducted by simulating the whole vane. Within the Reynolds-averaged Navier–Stokes (RANS) framework, the very widely used realizable k–ε (Rke) and the shear stress transport k–ω (SST) turbulence models were chosen for simulating the effect of the BR on the surface distribution of adiabatic effectiveness. The turbulence model which provided the most accurate steady prediction, i.e., Rke, was selected for running detached eddy simulation (DES) at the intermediate value of BR = 3. Fluctuations of the local temperature were computed by DES, due to the vortex structures within the shear layers between the main flow and the coolant jets. Moreover, mixing was enhanced both in the wall-normal and spanwise directions, compared to RANS modeling. DES roughly halved the prediction error of laterally averaged film cooling effectiveness on the suction side of the leading edge. However, neither DES nor RANS provided the expected decay of effectiveness progressing downstream along the pressure side, with 15% overestimation of ηav at s/C = 0.2.

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“…and also effect of interaction between main flow and coolant is studied by Rozati et al [6]. 3D flow analysis film cooling on turbine cascade blade for variation of Cp is studied by Fottner et al [7]. Nemdili et al [8] studied the computational modeling of film cooling considering the vortex generation at the coolant and main flow interaction.…”

Section: Past Workmentioning

confidence: 99%

Behaviour of Secondary Coolant Flow on the Turbine Blade Surface

Roy¹,

Preetam²

2016

World Congress on Mechanical, Chemical, and Material Engineering

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In this paper, the fluid mechanic behaviour of secondary flows, cooling injection from inside the blade, on the turbine blades surfaces has been studied for its aerodynamic influence. A standard T-106A turbine blade profile has been chosen for study. The blades are arranged in a linear cascade with a solidity of 0.5 and aspect ratio of 1.5. It is first intended to find the most effective single blowing location, which has been found at 10% of the blade surface from the leading edge. Then the study has focussed on finding a blowing ratio at which the secondary flow boundary layer sustains itself over most part of the turbine blade surfacesboth the suction and the pressure surfaces. Further, fluid mechanic studies have been conducted at this effective blowing ratio (≈ 0.8) to explore the boundary layer behaviour of the injected cooling flow. The boundary layer development has been studied at various chord-wise locations along the blades surfaces. It is observed that at the effective blowing ratio a single row of cooling injection at approximately 8.25% of axial chord behind the leading edge may be sufficient to create sustained cooling boundary layer over the entire turbine blade surfaces. The present study has been carried out with cold flows at low speeds to accommodate experimental validation in a low speed cascade tunnel in near future. The heat transfer related issues are not part of the present study.

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Reynolds Stress Transport Modeling of Film Cooling at the Leading Edge of a Symmetrical Turbine Blade Model

Cited by 24 publications

References 18 publications

Comparative Investigation on Heated Swirling Jets Using Experimental and Numerical Computations

Comparative Investigation on Heated Swirling Jets Using Experimental and Numerical Computations

Comparison of RANS and Detached Eddy Simulation Modeling Against Measurements of Leading Edge Film Cooling on a First-Stage Vane

Behaviour of Secondary Coolant Flow on the Turbine Blade Surface

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