DNS of Unsteady Heat Transfer Increase on a Curved Surface Due to Wake-Induced Turbulence

Conference paper

Abstract

From experimental studies it is well established that free-stream and wake-induced turbulence can increase the heat transfer on curved surfaces such as turbine blades or cylinders even if the mean flow matches corresponding laminar velocity profiles. Here, preliminary results of an investigation using (embedded) Direct Numerical Simulation (DNS) are reported that aim at identifying the responsible physical mechanisms for this phenomenon. The setup follows an existing experiment where a heated cylinder is subjected to the turbulent wake of a smaller cylinder placed upstream. The Reynolds number based on the diameter of the heated cylinder is Re=48,000. A key parameter identified in an experimental correlation is the characteristic turbulence level Tua that includes a dependency on Re and the mean flow acceleration. For the present study, Tua is an order of magnitude higher than those reported in any previous DNS. The obtained Nusselt number is in good agreement with the experimental correlation. More and better resolved data is currently produced for further analysis.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    P.J. Magari and J.E. LaGraff. Wake-induced unsteady stagnation-region heat transfer measurements. Journal of Turbomachinery, 116:29–38, Jan. 1994. CrossRefGoogle Scholar
  2. 2.
    N. Frössling. Evaporation heat transfer and velocity distribution in two-dimensional and rotationally-symmetric laminar boundary layer flow. NACA TM-1432, 1958. Google Scholar
  3. 3.
    K. Dullenkopf and R.E. Mayle. The effects of incident turbulence and moving wakes on laminar heat transfer in gas turbines. Journal of Turbomachinery, 116:23–28, 1994. CrossRefGoogle Scholar
  4. 4.
    J. Wissink and W. Rodi. Direct numerical simulation of heat transfer from the stagnation region of a heated cylinder affected by an impinging wake. Submitted to J. Fluid Mech., 2010. Google Scholar
  5. 5.
    J.G. Wissink and W. Rodi. Large-scale computations of flow around a circular cylinder. In Michael Resch, Sabine Roller, Peter Lammers, Toshiyuki Furui, Martin Galle, and Wolfgang Bez. High Performance Computing on Vector Systems 2007. Springer-Verlag Berlin Heidelberg, 2008. Google Scholar
  6. 6.
    L. Venema, D. von Terzi, H.-J. Bauer, and W. Rodi. DNS of heat transfer increase in a cylinder stagnation region due to wake-induced turbulence. In Proceedings of ETMM-8, 9–6 June 2010, Marseille, France, 2010. Google Scholar
  7. 7.
    C. Hinterberger. Dreidimensionale und tiefengemittelte Large-Eddy Simulation von Flachwasserströmungen. PhD thesis, University of Karlsruhe, 2004. Google Scholar
  8. 8.
    J. Wissink and W. Rodi. Heat transfer from the stagnation area of a heated cylinder at Re d=140000 affected by free-stream turbulence. In Proceedings of ETMM-8, 9–6 June 2010, Marseille, France, 2010. Google Scholar
  9. 9.
    D.A. von Terzi, R.D. Sandberg, and H.F. Fasel. Identification of large coherent structures in supersonic axisymmetric wakes. Computers & Fluids, 38(8):1638–1650, 2009. CrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • D. von Terzi
    • 1
  • L. Venema
    • 1
  • H.-J. Bauer
    • 1
  • W. Rodi
    • 2
  1. 1.Institut für Thermische Strömungsmaschinen, Karlsruhe Institute of Technology (KIT)Universität KarlsruheKarlsruheGermany
  2. 2.Institut für Hydromechanik, Karlsruhe Institute of Technology (KIT)Universität KarlsruheKarlsruheGermany

Personalised recommendations