This proposal refers to the Clean Sky 2 topic JTI-CS2-2018-CfP08-ENG-01-36 “Optimizing impingement cooling”. The objective of ACCENTO (Active Clearance Control dEsigN and characTerizatiOn) project is to carry out a series of advanced investigations on different Low-Pressure Turbine Active Clearance Control (LPTACC) system pipes and target plates.

The aim is to develop design/verification procedures and models to confidently predict the impinging system aero-thermal behaviour. This goal will be pursued by means of dedicated experimental tests and numerical simulations. The great ambition of the ACCENTO program is to design a modular test rig able to accommodate long ACC pipes (0.8 m to 1.5 m) which will be operated in engine representative conditions.

The rig will be able to provide reliable data for impingement cooling heat transfer characterization in a wide range of operating points. The radiative heat transfer impact on the system performance will be also accounted for. The rig will provide high quality data in conjunction with controlled operating conditions to validate CFD tools for the heat transfer and, more in general, for the ACC system characterization.

The expected outcomes of the project are the design, the commissioning and the testing of a modular rig for ACC heat transfer process characterization, the validation of CFD methodologies for such systems analysis and the development of design correlations for both the impingement holes discharge coefficient and for the jets Nusselt number. Moreover, thanks to the modularity of the developed rig, future and successive tests and analyses will be possible.