Research Papers: Gas Turbines: Turbomachinery

An Energy-Based Method for Predicting the Additive Effect of Multiple Film Cooling Rows

[+] Author and Article Information
Benjamin Kirollos

Osney Thermofluids Laboratory,
Department of Engineering Science,
University of Oxford,
Parks Road,
Oxford OX1 3PJ, UK
e-mail: ben.kirollos@eng.ox.ac.uk

Thomas Povey

Osney Thermofluids Laboratory,
Department of Engineering Science,
University of Oxford,
Parks Road,
Oxford OX1 3PJ, UK
e-mail: thomas.povey@eng.ox.ac.uk

1Corresponding author.

Contributed by the Heat Transfer Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received March 2, 2015; final manuscript received March 14, 2015; published online July 14, 2015. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(12), 122607 (Jul 14, 2015) (7 pages) Paper No: GTP-15-1075; doi: 10.1115/1.4030907 History: Received March 02, 2015

There have been numerous studies reporting film effectiveness for film rows in isolation, which have led to correlations that are used for preliminary design. Many applications require multiple film cooling rows. Although there is some published data which deal with the combined effect of multiple rows, in most design situations the additive effect is computed using correlations for single rows. The most widely used method is the Sellers superposition method. In many applications, the method gives accurate results. Although the method is to some extent physically based, energy is not conserved within the model, and in certain situations this limitation can be shown to lead to an underprediction of the film effectiveness. In this paper, a new energy-based method for predicting the additive effect of multiple film cooling rows is outlined. The physical basis and limitations of the model are discussed. Predictions conducted using the new method are compared with computational fluid dynamics (CFD) data and contrasted with the Sellers method. In situations where energy conservation is required to avoid underprediction of effectiveness the method is shown to be advantageous.

Copyright © 2015 by Rolls-Royce plc
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 2

Control volume for a row in isolation [20]. Coolant is injected between xi-δx and xi, so for x<xi-δx, m·ei = 0.

Grahic Jump Location
Fig. 1

Layer temperatures using the Sellers [3] model

Grahic Jump Location
Fig. 3

Contol volume for the energy-based mixing model

Grahic Jump Location
Fig. 4

CFD solution domain

Grahic Jump Location
Fig. 5

CFD predictions of ηi(x). Injection locations are shown by vertical dotted lines.

Grahic Jump Location
Fig. 6

Local entrainment rate of mainstream gas for film rows in isolation (g/s per domain pitch). Results are shown only in the region dηi/dx≤0, i.e., once the film is established.

Grahic Jump Location
Fig. 7

Mass flow rate contained in each film layer m·i(x) (g/s per domain pitch)

Grahic Jump Location
Fig. 8

CFD prediction of η(x) compared to prediction using the Sellers model and the proposed energy-based mixing model

Grahic Jump Location
Fig. 9

Absolute difference between the film cooling effectiveness predicted by the Sellers model and the proposed model as a function of s/D and x/D




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