0
Research Papers

Uncertainty Quantification: A Stochastic Method for Heat Transfer Prediction Using LES

[+] Author and Article Information
M. Carnevale

Dipartimento di Energetica,
Università degli Studi di Firenze,
via di S. Marta, 3,
Firenze 50139, Italia;
Whittle Laboratory,
1 JJ Thompson Evenue,
University of Cambridge,
Cambridge CB3 0DY, UK

F. Montomoli

Whittle Laboratory,
1 JJ Thompson Evenue,
University of Cambridge,
Cambridge CB3 0DY, UK;
Division of Mechanical, Medical, and Aerospace Engineering,
University of Surrey,
Guildford GU2 7XH, UK

A. D’Ammaro

Whittle Laboratory,
1 JJ Thompson Evenue,
University of Cambridge,
Cambridge CB3 0DY, UK

F. Martelli

Dipartimento di Energetica,
Università degli Studi di Firenze,
via di S. Marta, 3,
Firenze 50139, Italia

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received August 2, 2012; final manuscript received August 31, 2012; published online June 28, 2013. Editor: David Wisler.

J. Turbomach 135(5), 051021 (Jun 28, 2013) (8 pages) Paper No: TURBO-12-1162; doi: 10.1115/1.4007836 History: Received August 02, 2012; Revised August 31, 2012

In computational fluid dynamics (CFD), it is possible to identify namely two uncertainties: epistemic, related to the turbulence model, and aleatoric, representing the random-unknown conditions such as the boundary values and or geometrical variations. In the field of epistemic uncertainty, large eddy simulation (LES and DES) is the state of the art in terms of turbulence closures to predict the heat transfer in internal channels. The problem is still unresolved for the stochastic variations and how to include these effects in the LES studies. In this paper, for the first time in literature, a stochastic approach is proposed to include these variations in LES. By using a classical uncertainty quantification approach, the probabilistic collocation method is coupled to numerical large eddy simulation (NLES) in a duct with pin fins. The Reynolds number has been chosen as a stochastic variable with a normal distribution. The Reynolds number is representative of the uncertainties associated with the operating conditions, i.e., velocity and density, and geometrical variations such as the pin fin diameter. This work shows that assuming a Gaussian distribution for the Reynolds number of ±25%, it is possible to define the probability to achieve a specified heat loading under stochastic conditions, which can affect the component life by more than 100%. The same method, applied to a steady RANS, generates a different level of uncertainty. New methods have been proposed based on the different level of aleatoric uncertainties which provides information on the epistemic uncertainty. This proves, for the first time, that the uncertainties related to the unknown conditions, aleatoric, and those related to the physical model, epistemic, are strongly interconnected. This result, which is idealized for this specific issue, can be extrapolated, and has direct consequences in uncertainty quantification science and not only in the gas turbine world.

FIGURES IN THIS ARTICLE
<>
Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 2

Mesh details: left—overall view; right—pin mesh

Grahic Jump Location
Fig. 3

Pressure coefficient pin 1, pin 2, pin 3, comparison CFD with experimental data

Grahic Jump Location
Fig. 4

Comparison of mean velocity U/Vmax in the midplane along the line (a–a) for rows 1–3

Grahic Jump Location
Fig. 5

Spectrum of velocity signal

Grahic Jump Location
Fig. 9

φ-parameter ration distribution in streamwise direction for NLES closure

Grahic Jump Location
Fig. 10

φ-parameter ration distribution in streamwise direction for RANS closure

Grahic Jump Location
Fig. 8

Statistical distribution of Nusselt number and σ: RANS calculation

Grahic Jump Location
Fig. 7

Statistical distribution of Nusselt number and σ: NLES calculation

Grahic Jump Location
Fig. 6

Nusselt average distribution

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In