Modeling and Validation of Transitional Flow Behavior in Two-Dimensional Geometries Via Open-Source

This study presents the development of a practical framework for predicting the laminar-to turbulent transition in two-dimensional flows with an emphasis on industrial applications. The methodology is built upon widely used open-source computational fluid dynamics (CFD) tools, including OpenFOAM for simulation, blockMesh for mesh generation, and ParaView for visualization and post-processing. The research comprehensively addresses the fundamental governing equations of fluid flow, examines appropriate boundary conditions, and evaluates turbulence models with a particular focus on transition modeling techniques. Different solver configurations are employed based on flow compressibility: simpleFoam and pimpleFoam are used for incompressible flows, while rhoSimpleFoam is adopted for compressible flow regimes. The study systematically investigates numerical stability, solution convergence, and consistency by implementing various boundary condition types and discretization schemes. Grid independence tests are performed, and the results are validated through both experimental data and analytical benchmarks. Initial test cases include canonical flow problems, followed by more complex simulations involving airfoil geometries such as NACA4412. In addition to conventional CFD modeling, a supplementary analysis inspired by the LASTRAC (Langley Stability and Transition Analysis Code) approach is carried out. This allows for a comparative assessment of transition prediction accuracy between traditional CFD solvers and linear stability-based methods. The overall framework not only demonstrates the applicability of open-source tools in solving real-world engineering problems but also contributes to a deeper understanding of transitional flow phenomena in aerodynamic configurations.