CFD simulation of low-emission premixed gas turbine injectors

The aim of the thesis work, developed in collaboration with EthosEnergy S.p.A, is to assess the impact of employing additive manufacturing (AM) techniques on the performance of a low emissions premixed gas turbine injector. This investigation compares fluid dynamic simulation results for two injector designs: traditional and adapted to additive manufacturing techniques. In case of particularly complex geometries, it is possible to fully exploit the advantages that additive manufacturing implies, making the production of the component more sustainable and economically advantageous. The thesis begins with an overview of Turbogas power plants and injection systems, with a brief mention of the possible use of hydrogen. In this first part, a detailed explanation about the models implemented within Ansys FLUENT® is also present. Subsequently, it proceeds with an in-depth analysis comparing the original injector design with the modifications required for the Laser Powder Bed Fusion AM technique implementation. The research then shifts its focus to the 3D CFD simulations. For both the design configurations, the numerical model is firstly validated through airflow tests and then used to examining the mixing behavior of air and methane under actual operating conditions. In conclusion, the obtained results are compared to highlight advantages and disadvantages from a fluid dynamic point of view of using AM techniques.