PALOMA will design and test a passively actuated opening system that will allow a volume of secondary air flow to be diverted into the engine core area for cooling purposes. Being entirely passive, no external electrical, hydraulic or pneumatic power will be required to run or control the system. The system will use a heat pipe to transfer the necessary heat to a shaped memory alloy (SMA) component whose movement will, through a set of mechanical linkages, open a flap set within the nacelle inner walls. This system will permit an optimisation of the engine thermal management and performance whilst needing minimal maintenance.
The results of the tests performed on the functional prototype will be integrated into the design of a demonstrator (which may also be used for flight tests) which in turn will be manufactured and tested. Modelling activities will support the project throughout its execution.
The PALOMA solution will be fully European and will bring together: a thermal management engineering and modelling company, a heat pipe specialist, an SMA specialist with unique design and industrial manufacturing capabilities and a broad-spectrum engineering company specialised in aircraft and engine integration.
Based on an agreed set of requirements, the project partners will first perform a trade-off in terms of possible heat pipe and SMA material and geometric forms, followed by their full characterisation. This information will permit a) the design of the system to be performed after a trade-off considering the constraints (positioning, extreme temperatures and aircraft accelerations) linked to the installation of such a system in a nacelle b) the modelling of the system’s behaviour. Having completed the design, a functional prototype will be tested on a specifically design test bench to simulate operation conditions including pressure, temperature and vibration according to the requirements of the DO160, mandatory for all equipment used on aircraft.