Grid resolution influence on the results of three-dimensional flow calculations in turbomachine flowpaths at use RANS models

• Main Authors: Ершов, С. В., Яковлев, В. А.
• Format: Article
• Language: Russian
• Published: Journal of Mechanical Engineering 2015
• Subjects: turbomachinery cascades; CFD modeling; viscous flow; mesh convergence; shock waves; wakes; separations; losses; решетки турбомашин; CFD моделирование; вязкий поток; сеточное разрешение; скачки уплотнения; следы; отрывы; потери; УДК 621.165 621.438; решітки турбомашин; CFD моделювання; в’язкий потік; сіткове розділення; стрибки ущільнення; сліди; відривання; втрати
• Online Access: https://journals.uran.ua/jme/article/view/57503

The paper considers the question of the influence of a difference mesh refinement on a numerical solution for calculations of the three-dimensional viscous flows in turbomachinery, using the RANS flow models and the second-order accurate numerical methods. The flow computations are performed for a number of turbine and compressor cascades for which successively refined meshes were generated. The meshes are of H-type with an approximate orthogonality near the solid walls. The CFD solver F, that based on the second-order accurate ENO scheme, is used for the flow computations. The simplified multigrid algorithm and local time stepping permits a convergence acceleration. The results obtained are estimated in their ability both to resolve qualitatively the transonic flow pattern and to predict quantitatively the losses. It is concluded that for scientific researches of the 3D turbomachinery flows, it makes sense to use the difference meshes with number of cells from 106 to 108 per a single blade-to-blade passage, while for engineering calculations, a mesh of less than 106 cells per the single blade-to-blade passage could be sufficient under certain conditions.