Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
A numerical study on the capability of the γ−θ turbulence
model for predicting the laminar/turbulent transition in the
boundary layer developing around a supercritical airfoil (NLR
7301) is described. The range in the Mach number explored is
[0.3, 0.825], thus covering a fully transonic flow regime. For
this purpose, a CFD solver (ANSYS CFX©) is used on a hybrid
structured-triangular grid, where an accurate mesh setup of the
wall boundary layer was performed in order to ensure (i) a
value of y+ less than 6 everywhere and (ii) a number of
boundary layer rows within the physical boundary layer no less
than 4. Results obtained are compared to the experimental data
described in the open literature and discussed in detail. Despite
the various sources of uncertainty affecting the experimental
data, the results regarding the transition location revealed a
very good model predictive capacity for low-to-medium Mach
numbers (Mach<0.6), while exhibiting a less satisfactory ability
in the transonic regime (Mach>0.6). In this case, prediction of
transition location on both sides of the airfoil is still accurate
even if the correlation on the pressure distributions gets poorer.
