MODELLING OF THE EFFECT OF THE FOREGOING WAKE ON THE BYPASS TRANSITION ON THE AIRFOIL

A modified algebraic model of the bypass transition was used for the simulation of the flow around the symmetrical airfoil NACA 0012 in the tandem configuration. The transition model is based on local variables only to enable its application for complex flow geometry using unstructured computational grids. The attention was especially focused on the flow near the leading edge where the boundary layer is not yet fully developed while used empirical correlations were established for the boundary-layer flow. The numerical simulation was compared with experiments of Lee and Kang [1] carried out for the Reynolds number Rec = (2÷6)×105 , the zero angle of attack and various distance between both airfoils. The agreement of numerical simulation with experimental data is quite satisfactory.

[1]  Florian R. Menter,et al.  Correlation-Based Transition Modeling for Unstructured Parallelized Computational Fluid Dynamics Codes , 2009 .

[2]  W. Haase,et al.  Navier-Stokes Airfoil Computations Including Transitional Flow Regions , 1999 .

[3]  Gregory J. Walker,et al.  Transition Length Prediction for Flows With Rapidly Changing Pressure Gradients , 1995 .

[4]  D. K. Walters,et al.  A New Model for Boundary Layer Transition Using a Single-Point RANS Approach , 2004 .

[5]  Paul A. Durbin,et al.  Toward Improved Prediction of Heat Transfer on Turbine Blades , 2002 .

[6]  P. Bradshaw,et al.  Modeling of Flow Transition Using an Intermittency Transport Equation , 2000 .

[7]  Karl Hiemenz,et al.  Die Grenzschicht an einem in den gleichförmigen Flüssigkeitsstrom eingetauchten geraden Kreiszylinder , 1911 .

[8]  E. Dick,et al.  Intermittency based RANS bypass transition modelling , 2006 .

[9]  Roddam Narasimha,et al.  The laminar-turbulent transition zone in the boundary layer , 1985 .

[10]  P. Durbin.  Near-wall turbulence closure modeling without “damping functions” , 1991, Theoretical and Computational Fluid Dynamics.

[11]  Robin Blair Langtry,et al.  A correlation-based transition model using local variables for unstructured parallelized CFD codes , 2011 .

[12]  Reinhard Niehuis,et al.  Unsteady Navier-Stokes Simulation of a Transonic Flutter Cascade Near-Stall Conditions Applying Algebraic Transition Models , 2006 .

[13]  H. Lee,et al.  Flow Characteristics of Transitional Boundary Layers on an Airfoil in Wakes , 2000 .

[14]  Johan C. Kok,et al.  Resolving the Dependence on Freestream Values for the k- Turbulence Model , 2000 .