CFD based design and analysis of centripetal distributor system for an axial research turbine

This thesis presents the design work for the inlet guide vanes for centripetal distributor of an axial turbine. The main goal of the work is to maximize the flow uniformity at the outlet of the distributor, also providing an axial flow at the inlet of the test turbine operating the Laboratorio di Fluidodinamica delle Macchine of the Politecnico di Milano. For this purpose, firstly the complete flow region inside the distributor is modeled and simulated to the flow behavior without. Secondly simulations were conducted with a commercial CFD including in the distributor system in presence an Inlet Guide Vane, testing several blade profiles and configurations in order to find an optimum blade profile with regards to both flow behavior (yaw angle) and simplicity for manufacturing. Results from the simulations were analyzed in detail and a certain blade profile and configuration was chosen to be manufactured and to be used in the test rig. Lastly as the spanwise variation of the yaw angle couldn’t be prevented in any of the configurations it was decided to introduce a honeycomb structure at the outlet of the distributor to eliminate the residual flow angle and span-wise variation, at the expense of a slight the increase in total pressure loss.