Particle deposition on HTP nozzle: full 3D investication and secondary flows effect

Gas turbines can operate in an environment dispersed with particles that, if ingested by the machine, may have a detrimental effect on the aerodynamic performances. Therefore, the aim of this work is to gather information about how particles adhesion is influenced by geometrical features of gradually growing complexity. At this scope, the particle deposition problem is investigated from the numerical standpoint. Specifically, the LS-89 transonic high pressure turbine (HPT) vane is simulated and an encounter with a volcanic ash cloud is modelled. Three simulations are carried out: a 2D simulation has been compared with the set of 3D simulations. Different levels of complexity of the geometry have been considered for the 3D case: the endwall effect has been assessed considering the presence of a variable radius fillet and comparing it with the prediction obtained by a cylindrical extrusion. The proposed analysis provides indications on the 2D and 3D prediction with regards to particle deposition problems. The sticking pattern of the particle has been investigated in relation to the different nature of secondary flows.