Валідація й верифікація моделі турбулентності та топології розрахункової сітки при моделюванні течії в дворядній компресорній решітці

The study substantiates the turbulence model and the topology of the computational grid when modeling the flow in a tandem compressor cascade. The research object is a tandem compressor cascade. This study aims to verify and validate the turbulence model and the computational grid topology when simulating the flow around a tandem compressor cascade. To achieve the goal, the following tasks were solved: a three-dimensional model of the working medium was built when simulating the flow around the tandem compressor blades; the flow around the tandem compressor blades was modeled using four models of turbulent viscosity SST, SST Gamma-Theta, LRR, k-ω was carried out; modeling of the flow around the tandem compressor blades was modeled using three topological calculation grids; and the obtained results were evaluated by comparing the results of a numerical and physical experiment. A 3D model of the stand was built to conduct a numerical experiment of flow simulation, on which 5 blades of the first row and 13 blades of the second row are placed. To create a calculation grid, a structured grid using so-called O-grid blocks is built around smooth aerodynamic profiles. Three calculation grid versions were built to carry out the research: calculation grid 1–138340, grid 2–224546, and grid 3–270633 elements. Four turbulence models were tested in the work – SST, SST Gamma-Theta, LRR, k-ω. Results: The obtained calculation results allow us to state that Ansys CFX models gas-dynamic processes occurring in a compressor with tandem blades with sufficient accuracy. In addition, the SST turbulence model gives the greatest convergence of the modeling results with the calculation results. Grid 3, which corresponds to 50 calculation cells along the blade chord, gives the greatest convergence when determining the grid’s pressure losses. Consequently, the SST turbulence model and grid size with at least 50 calculation cells along the chord are selected for further research. The scientific novelty and practical significance of the conducted research are based on the data obtained for the verification and validation of the turbulence model and the topology of the calculation grid in the simulation of the flow around a tandem compressor cascade.