Evaluation of Different Turbulence Models and Different Numerical Solvers for a Transonic Turbine Blades Cascade
Dr. Amgad Mohamed Abbas
Dr. Amgad M. Abbas received his B.Sc. in Mechanical Engineering from Alexandria University, Egypt, in 2005. He earned his M.Sc. in advanced heat transfer and turbulent flow, and his Ph.D. in 2020, focusing on advanced heat transfer, turbulent flow, and nanotechnology applications through experimental and numerical studies.
With over 20 years of experience in mechanical engineering and project management, he currently serves as the Maintenance Planning General Manager at Abu Qir Fertilizers. He also maintains active research collaborations with Abu Qir Fertilizers, Alexandria University, and the Egyptian Military Technical College, bridging industry and academia.
Dr. Amgad has published several papers in high–impact Q1 international journals, with over 100 citations, including work on turbulence models and numerical solvers for transonic turbine blade cascades, enhancing the NASA model (NASA/TM-1999-209296). He has been actively publishing since 2010, with ongoing research in nanotechnology applications.
Name: Amgad Mohamed Abbas
Affiliation: Maintenance Planning General Manager
Organization: Abu Qir Fertilizers and Chemical Industries Co., Alexandria, Egypt
Abstract
The gas path over turbine blades constitutes a highly complex flow field due to variations in flow regimes and the associated heat transfer mechanisms. This investigation is devoted to studying the two- and three-dimensional predictive modeling capabilities for external airfoil heat transfer using both the Pressure-Based Solver (PBS) and the Density-Based Solver (DBS). The results demonstrate the effects of strong secondary vortices, laminar-to-turbulent transition, and the characteristics of stagnation regions.
The simulations were performed on an irregular quadrilateral grid using the Fluent 6.3 software package, which solves the Reynolds-Averaged Navier–Stokes (RANS) equations using the finite volume method with second-order accuracy. Data were obtained at exit Reynolds numbers up to the facility maximum of 2.50 × 10⁶, with a blade aspect ratio of 1.17. It was concluded that relatively fine three-dimensional computational grids are required to accurately capture local heat transfer governed by the complex three-dimensional structure of secondary flows.
Numerical simulation results for two- and three-dimensional turbulent flow heat transfer in a transonic turbine cascade are presented using several turbulence models, including the Spalart–Allmaras, RNG k–ε, and SST k–ω models.
Detailed heat transfer predictions are presented for a power-generation turbine rotor with a nominal turning angle of 127° and an axial chord length of 130 mm. The resulting blade-passage flow is highly three-dimensional due to the large flow turning and the development of three-dimensional boundary layers. Comparisons with experimental and numerical results reported by Giel et al. (2004) show good agreement, particularly when using the density-based solver in conjunction with the Spalart–Allmaras turbulence model.
