Development of 2D turbulent navier-stokes solver for cartesian grids

Tez Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tez Danışmanı: Mehmet Haluk Aksel; Özgür Uğraş Baran

Tezin Onay Tarihi: 2022

Tezin Dili: İngilizce

Özet:

A computer code is developed for solving two-dimensional compressible Reynolds-Averaged Navier-Stokes (RANS) equations. The compressible RANS equations are closed with the negative version of the Spalart-Allmaras (SA) turbulence model. Quad-tree-based Cartesian/Quad grids are used to discretize the solution domain. Then, a cell-centered, finite-volume approach is applied to solve turbulent flows. Solution-based mesh adaptivity is used to obtain mesh-free solutions. Since a quad-tree-based data storage is used, mesh refinement and coarsening are done efficiently. Flow variables are reconstructed by using the weighted and unweighted least squares approach. Convective fluxes are formulated with the approximate solver of Roe and limited with Venkatakrishnan's limiter. Formulation of convective terms of the turbulence model is achieved by using first-order upwinding. The gradients used in viscous calculations are obtained using a modified average of the reconstructed variables.