COMPUTATIONAL FLUID DYNAMICS FOR THE ANALYSIS OF THE FLOW AROUND A SQUARE PRISM IN TURBULENT REGIME

Resumo

The use of models in Computational Fluid Dynamics (CFD) has been increasing
considerably, since the description of the phenomena in an analytical way is sometimes very complex
and wind tunnel tests can not always be used. In this research, the characteristics of the turbulent flow
around an obstacle of square section, for different Reynolds numbers, were studied, using the
computer code in CFD, OpenFoam, which is an open source program in C ++ programming language.
The choice of the OpenFoam code was due to the fact that is a free open source program and has a
great study potential. The square obstacle was chosen because it has similarities with several structures
studied by the engineering, that is to say, it is a blunt body with sharp corners and has many already
consolidated data. The beginning of the study was done by performing a mesh analysis. For this, a
value of the Reynolds number was set and analyzes were carried out with meshes of different
refinements in order to evaluate the sensitivity of the mesh. The turbulence model used was the RANS
category (Reynolds Averaged Navier-Stokes Equation) and the values of the aerodynamic coefficients
found were compared with those obtained in the literature. The most efficient mesh was defined
relating the aerodynamic coefficients with the execution time of the analysis and the level of the
refinement of the meshes. In a second instance, the Reynolds number were varied and thus the values
of the aerodynamic coefficients and their fluctuations were obtained.