ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
CALCULATION OF HEAT TRANSFER IN TURBULENT TRANSPIRED BOUNDARY LAYERS
Abstract
Calculations have been performed to assess the
relative performance of two recently proposed near-wall
turbulence models, namely the one-equation
model of Norris and Reynolds [3] and the two-equation model of Lam and Bremhorst [4]. The testcases, to which the models have been subjected, span a wide range of transpired and non-transpired flow conditions. In particular, the heat transfer behaviour of
boundary layers in zero, adverse and favourable pressure
gradients has been explored. In addition, cases
with step changes in blowing rate were calculated.
The comparison with experimental data is mainly in
terms of skin friction coefficients and Stanton numbers
as well as velocity and temperature profiles and shows
that the one-equation model predicts the effects of
transpiration on equilibrium boundary layers correctly,
but reveals difficulties in reproducing relaminarizing
and relaxing flows. On the other hand the two-equation
model simulates these features correct. Modifications
of the latter are needed, however, in order to
improve its performance for equilibrium cases with
transpiration and for boundary layers under adverse
pressure gradients.