Uncertainty analysis of adiabatic wall temperature measurements in turbine experiments

Lavagnoli, Sergio; Maesschalck, C. De; Paniagua, Guillermo

doi:10.1016/j.applthermaleng.2015.02.048

Cited by 23 publications

(4 citation statements)

References 26 publications

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“…The heat flux measurement suffers from a bias error of approximately ±6-7%, mainly due to uncertainties in thermal properties. The precision error in time-resolved heat flux is of the order of ±2-3% [39].…”

Section: Tip Flow Measurementsmentioning

confidence: 97%

Experimental and Numerical Investigation of Optimized Blade Tip Shapes: Part I — Turbine Rainbow Rotor Testing and CFD Methods

Cernat

Pátý

Maesschalck

et al. 2018

Volume 5B: Heat Transfer

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Blade tip design and tip leakage flows are crucial aspects for the development of modern aero-engines. The inevitable clearance between stationary and rotating parts in turbine stages generates high-enthalpy unsteady leakage flows that strongly reduce the engine efficiency and can cause thermally induced blade failures. An improved understanding of the tip flow physics is essential to refine the current design strategies and achieve increased turbine aerothermal performance. However, while past studies have mainly focused on conventional tip shapes (flat tip or squealer geometries), the open literature suffers from a shortage of experimental and numerical data on advanced blade tip configurations of unshrouded rotors. This work presents a complete numerical and experimental investigation on the unsteady flow field of a high-pressure turbine, adopting three different blade tip profiles. The aerothermal characteristics of two novel high-performance tip geometries, one with a fully contoured shape and the other presenting a multi-cavity squealer-like tip with partially open external rims, are compared against the baseline performance of a regular squealer geometry. The turbine stage is tested at engine-representative conditions in the high-speed turbine facility of the von Karman Institute. A rainbow rotor is mounted for simultaneous aerothermal testing of multiple blade tip geometries. On the rotor disk, the blades are arranged in sectors operating at two different clearance levels. A numerical campaign of full-stage simulations was also conducted on all the investigated tip designs to model the secondary flows development and identify the tip loss and heat transfer mechanisms. In the first part of this work, we describe the experimental setup, instrumentation and data processing techniques used to measure the unsteady aerothermal field of multiple blade tip geometries using the rainbow rotor approach. We report the time-average and time-resolved static pressure and heat transfer measured on the shroud of the turbine rotor. The experimental data are compared against CFD predictions. These numerical results are then used in the second part of the paper to analyze the tip flow physics, model the tip loss mechanisms and quantify the aero-thermal performance of each tip geometry.

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Section: Tip Flow Measurementsmentioning

confidence: 97%

Experimental and Numerical Investigation of Optimized Blade Tip Shapes: Part I — Turbine Rainbow Rotor Testing and CFD Methods

Cernat

Pátý

Maesschalck

et al. 2018

Volume 5B: Heat Transfer

Self Cite

View full text Add to dashboard Cite

show abstract

“…The results from such an analysis can be fed back into the manufacturing process to implement improvements that reduce the impact of geometric variability. Other examples of uncertainty quantification and sensitivity analysis are Seshadri et al [5], Lavagnoli et al [6], Ghisu and Shahpar [7], and Fiedler et al [8]. Furthermore, these results can be used within a (robust) optimization (such as in Verstraete et al [9], Padulo et al [10], Seshadri et al [11], Dow and Wang [12], Kamenik et al [13], and Dittmann et al [14]).…”

Section: Introductionmentioning

confidence: 99%

Improvements in Probabilistic Strategies and Their Application to Turbomachinery

Prots,

Voigt,

Mailach

2024

Aerospace

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This paper discusses various strategies for probabilistic analysis, with a focus on typical engineering applications. The emphasis is on sampling methods and sensitivity analysis. A new sampling method, Latinized particle sampling, is introduced and compared to existing sampling methods. While it can increase the quality of surrogate models, an optimized Latin hypercube sampling is mostly preferable as it shows slightly better results. In sensitivity analysis, the difficulty lies in correlated input variables, which are typical in engineering applications. First, the Sobol indices and the Shapley values are explained using an intuitive example. Then, the modified coefficient of importance is introduced as a new sensitivity measure, which can be used to reliably identify input variables without functional influence. Finally, these results are applied to a turbomachinery test case. In this case, the flow field of a compressor row is investigated, where the blades are subjected to geometric variability. The profile parameters used to describe the geometric variability are correlated. It is shown that the variability of the maximum camber and the thickness of the leading edge have a decisive influence on the variability of the isentropic efficiency.

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“…Today, even fuel-efficient cars are equipped with turbocharging [4]. However, the use of turbocharging in vehicles leads to a significant increase in the operating temperature and loading modes [5,6,7]. This requires the use of more reliable operating materials and strict adherence to maintenance regulations, the violation of which significantly decreases engine durability [8,9].…”

Section: Introductionmentioning

confidence: 99%

Assessing the Sensitivity of the Rundown of a Turbocharger Rotor Shaft to Determine Its Technical Condition

Gritsenko,

Shepelev,

Burtsev

et al. 2023

Tribol. Ind.

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In response to the growing concern about environmental sustainability and natural resource depletion, car manufacturers are looking for ways to make their vehicles more efficient. One approach is to use turbocharging technology, which compresses the air entering the engine cylinder for a higher power density per unit of displacement volume. Although turbocharging can reduce carbon emissions by improving engine performance, it has several disadvantages, including reduced reliability and service life, increased maintenance frequency and cost, and reliance on high quality fuels and lubricants. This study investigates the possible continuous monitoring of the running time of the turbocharger (TCR) rotor shaft and the influence of various input parameters, such as oil pressure and oil temperature, on TCR wear. We hypothesize that the continuous monitoring of these variables could prevent breakdowns and optimize turbocharger operation. We created a test bench consisting of an internal combustion engine (ICE) combined with a turbocharging system which includes an independent lubrication and braking mechanism. Our experiments demonstrated a positive correlation between oil inlet temperature and wear sensitivity over time. We also revealed a close relationship between oil inlet pressure, thermal properties, initial rotor speed, and wear duration. These results indicate that continuous qualitative and quantitative monitoring of wear progression can predict impending failures and increase turbocharger efficiency. The evaluation of the TCR sensitivity to wear time can assess both the quality of the turbocharger assembly at the manufacturing stage and the adequacy of its preliminary adaptation in real conditions.

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Uncertainty analysis of adiabatic wall temperature measurements in turbine experiments

Cited by 23 publications

References 26 publications

Experimental and Numerical Investigation of Optimized Blade Tip Shapes: Part I — Turbine Rainbow Rotor Testing and CFD Methods

Experimental and Numerical Investigation of Optimized Blade Tip Shapes: Part I — Turbine Rainbow Rotor Testing and CFD Methods

Improvements in Probabilistic Strategies and Their Application to Turbomachinery

Assessing the Sensitivity of the Rundown of a Turbocharger Rotor Shaft to Determine Its Technical Condition

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