Design of Power Turbine Flow Path of Small Aeroengine

Abstract

An approach to the design of a turbine flow part is presented. The approach is based on the analysis of design and operational constraints, on the definition of areas of engineering solutions that ensure the achievement of defined parameters with an acceptable technical risk. The considered turbine is a Power Turbine (PT) of a small aviation gas-turbine engine. The PT is an uncooled single-stage axial turbine with a shrouded rotor. Before PT there is a diffuser Inter-Turbine Duct from the high-pressure turbine. The constraints, assumptions and criterion of effective designing of the PT flow path at the stage of one-dimensional design (based on the mean diameter) are considered. They include the constraints on the Inter-Turbine Duct expansion, on the mechanical loads of rotor blades, the flow parameters at the outlet of the turbine, and others. The solution scope defined as region in a middle diameter – blade span ratio and a rotational speed coordinates. For designed flow path the blade rows was profiled and verifying 3D calculations was carried out. 1D calculations performed by in-house code. For 3D calculation CFD code FlowER used. According numerical results PT flow path ensure specified parameters. The works were carried out within the Framework Programme 7 (FP7) EU project Efficient Systems and Propulsion for Small Aircraft (ESPOSA) – under the Grant Agreement number №: ACP1-GA-2011-284859.