The proposal described the methodology to be used for engine installation design optimisation in heavy helicopters. Specific objectives of such activity were the following:
- to set up of a comprehensive and fully automatic optimal design tool, integrating the software suitable for engine installation analysis and in-house multi-objective optimization algorithms already developed by the applicant;
- to apply such tool for the efficiency improvement of engine installation components based on the boundary conditions given by the manufacturer, in order to achieve a significant reduction in the engine installation losses.
The HEAVYcOPTer project was aimed at improving the engine integration of a heavy helicopter, namely the AW101, by using advanced numerical optimisation methodologies. In particular, engine intake and exhaust systems were considered as components to be optimised.
The intake performance was ameliorated by reducing the total pressure losses and the inlet flow distortion at the engine interface at two relevant flight conditions, i.e. hover and forward flight. Reduction in the backpressure was instead considered as the main goal of the exhaust optimization, together with a proper balance of hot and cold flows for guaranteeing appropriate cooling of the engine bay. In addition, some further aerodynamic characteristics of the engine installation, like for instance potential tailboom heating, potential re-ingestion of hot gases in ground idle conditions, and effect of rotor inflow in some representative flight conditions were taken into account.
To this purpose, an in-house multi-objective evolutionary algorithm was used coupled with both commercial and open-source CFD solvers. The final results confirmed the achievements of substantial improvements in engine installation performance.