Comparison of Predictions From Conjugate Heat Transfer Analysis of a Film-Cooled Turbine Vane to Experimental Data

Ni, Ron-Ho; Humber, William; Fan, George; Clark, John P.; Anthony, Richard; Johnson, Jamie J.

doi:10.1115/gt2013-94716

Cited by 15 publications

(11 citation statements)

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“…The use of radiation based wall temperature measurents in hot test rigs can result in poor agreement with CHT CFD, possibly due to emissivity calibration problems, as the emissivity is a function of temperature [30,31]. When imbedded thermocouples are used as in the present work, there is a growing body of evidence, particularly for metal turbine blade studies of agreement between CHT CFD predictions and metal temperature measurements [32,33]. For flat wall effusion cooling Oguntade et al [34 -36], have shown good agreement with experimental hot test result for Nimonic-75 effusion walls with imbedded thermocouples.…”

Section: Previous Work On Cht Cfd In Gas Turbinesmentioning

confidence: 91%

Conjugate Heat Transfer Computational Fluid Dynamic Predictions of Impingement Heat Transfer: The Influence of Hole Pitch to Diameter Ratio X/D at Constant Impingement Gap Z

El-Jummah

Husain

Andrews

et al. 2014

Journal of Turbomachinery

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Conjugate heat transfer (CHT) computational fluid dynamic (CFD) predictions were carried out for a 10 × 10 square array of impingement holes, for a range of pitch to diameter ratio X/D from 1.9 to 11.0 at a constant impingement gap Z of 10 mm and pitch X of 15.24 mm. The variation of X/D changes the impingement wall pressure loss for the same coolant mass flow rate and also changes the interaction with the impingement gap cross-flow. The experimental technique to determine the surface averaged heat transfer used the lumped capacity method with Nimonic-75 metal walls with imbedded thermocouples and a step change in the hot wall cooling to determine the heat transfer coefficient h from the transient cooling of the metal wall. The test wall was electrically heated to about 80 °C and then transiently cooled by the impingement flow and the lumped capacitance method was used to measure the locally surface average heat transfer coefficient. The predictions and measurements were carried out at an impingement jet mass flux of 1.93 kg/s m2 bar, which is a typical coolant flow rate for regenerative impingement cooling of low NOx gas turbine combustor walls. The computations were conducted for a fixed hot side temperature of 353 K that was imposed at the hot face of the target wall. The wall temperatures as a function of distance along the gap were computed together with the impingement gap aerodynamics. Surface average heat transfer coefficient h and pressure loss predictions were in good agreement with the experimental measurements. However, there was less good agreement for the axial variation of the local surface averaged h for lower values of X/D. The surface averaged heat transfer to the impingement jet wall was also computed and shown to be roughly 70% of target wall impingement heat transfer.

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Section: Previous Work On Cht Cfd In Gas Turbinesmentioning

confidence: 91%

Conjugate Heat Transfer Computational Fluid Dynamic Predictions of Impingement Heat Transfer: The Influence of Hole Pitch to Diameter Ratio X/D at Constant Impingement Gap Z

El-Jummah

Husain

Andrews

et al. 2014

Journal of Turbomachinery

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“…The insufficient diffusion led to overpredicted cooling effectiveness for attached jets and underpredicted effectiveness for detached jets. Ni et al [20,21] simulated a fully film cooled vane and endwall geometry under flow conditions consistent with a dual spool engine with a pressure ratio of 40. The conjugate simulations were performed using the standard k-x turbulence model.…”

Section: Relevant Literaturementioning

confidence: 99%

Conjugate Heat Transfer Measurements and Predictions of a Blade Endwall With a Thermal Barrier Coating

Mensch

Thole

Craven

2014

Journal of Turbomachinery

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Multiple thermal protection techniques, including thermal barrier coatings (TBCs), internal cooling and external cooling, are employed for gas turbine components to reduce metal temperatures and extend component life. Understanding the interaction of these cooling methods, in particular, provides valuable information for the design stage. The current study builds upon a conjugate heat transfer model of a blade endwall to examine the impact of a TBC on the cooling performance. The experimental data with and without TBC are compared to results from conjugate computational fluid dynamics (CFD) simulations. The cases considered include internal impingement jet cooling and film cooling at different blowing ratios with and without a TBC. Experimental and computational results indicate the TBC has a profound effect, reducing scaled wall temperatures for all cases. The TBC effect is shown to be more significant than the effect of increasing blowing ratio. The computational results, which agree fairly well to the experimental results, are used to explain why the improvement with TBC increases with blowing ratio. Additionally, the computational results reveal significant temperature gradients within the endwall, and information on the flow behavior within the impingement channel.

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“…Actually, CHT analysis is in the interest of gas turbine manufacturers to optimize cooling schemes and improve turbine durability during design and before committing to hardware. 36…”

Section: Discussionmentioning

confidence: 99%

Adiabatic and conjugate simulations on the flow field in a gas turbine vane with pressure side film cooling and trailing edge cutback

Ravelli

Barigozzi

2014

Proceedings of the Institution of Mechanical Engineers, Part A:

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The present study concentrates on the numerical investigation of pressure side film cooling in a linear nozzle vane cascade typical of a high-pressure turbine in gas turbine engines. The cooling scheme features a pressure side cutback and two rows of cooling holes located upstream of the cutback. The main goal is to evaluate the applicability of a simple numerical method, i.e. the steady incompressible Reynolds-averaged Navier Stokes, in such a complex industrial application. The simulations are performed according to an adiabatic and conjugate approach. Two values of the coolant-to-mainstream mass flow ratio ( MFR = 1% and 2.8%) are simulated at exit Mach number of M2 is = 0.2. The computed flow/temperature fields in the cooled regions of the vane pressure side are presented and compared to available measurements of: holes and cutback exit velocity and discharge behavior; boundary layer along traverses at strategic axial locations, adiabatic film cooling effectiveness. In addition, distributions of overall film cooling effectiveness and heat transfer coefficients are reported for the conjugate cases. Both adiabatic and conjugate techniques provide reasonable predictions of three-dimensional aerodynamic and thermal features of the investigated cooled vane. The conjugate heat transfer is much more complicated than one-dimensional conduction within the vane material.

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Comparison of Predictions From Conjugate Heat Transfer Analysis of a Film-Cooled Turbine Vane to Experimental Data

Cited by 15 publications

References 0 publications

Conjugate Heat Transfer Computational Fluid Dynamic Predictions of Impingement Heat Transfer: The Influence of Hole Pitch to Diameter Ratio X/D at Constant Impingement Gap Z

Conjugate Heat Transfer Computational Fluid Dynamic Predictions of Impingement Heat Transfer: The Influence of Hole Pitch to Diameter Ratio X/D at Constant Impingement Gap Z

Conjugate Heat Transfer Measurements and Predictions of a Blade Endwall With a Thermal Barrier Coating

Adiabatic and conjugate simulations on the flow field in a gas turbine vane with pressure side film cooling and trailing edge cutback

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