During the start project period, the work was focused on the predesign and design phases , which, supported by detailed state-of-the-art review, provided heat sink and bay designs that fulfilled the project requirements.
The subsequent design phase assured the optimum implementation of APG and MMCs into the heat sink, considering the manufacturing limits, refining aspects to obtain improved performances, etc.
Regarding Stage A, the Project has covered the design, manufacturing and testing (thermal, salt-fog, vibration) of the heat sinks. The results accomplished the requirements for temperature level, pressure drop and weight.
Regarding the integration of APG and MMC (Stage B), some coupon samples have been investigated, confirming the correct bonding between the materials, and reporting their equivalent conductivity.
In parallel, the Stage B design has also progressed, leading to three different options, manufactured and tested (thermal, salt-fog, vibration). The obtained results are satisfactory, with similar performance to Stage A.
In relation with the bay, the design has been progressively refined, from the PEM (box enclosing the heat sinks), the duct assembly managing the air flow towards the PEMs, and to the whole bay structure containing also other electric/electronic components. The tests on the duct assembly confirm an adequate flow and velocity uniformity at each heat sink channel. From the thermal side, the heat sinks integrated in the bay show very similar temperature levels compared to the corresponding stand-alone tests.
As a final overview of the results, the project has been able to design, manufacture and test successfully four different types of innovative heat sink. One of them incorporating APG , and the other three with different combinations of APG and MMC. The tests have confirmed the units can dissipate the expected heat with surface temperatures below the given threshold, keeping the air pressure drop and the weight within the limits. This result is very important as conclusive to confirm to the TM and Clean Sky that the innovation track of combining new high temperature electronics (SiC) with innovative high-tech material heat sinks is promising. Some improvements have also been identified after the first time manufacturing of the new heat sinks during the project, thus future activities will probably enhance the current performance and robustness levels.
The final implementation into the aircraft cannot rely only in an innovative and efficient air cooled heat sink; there is the need to provide adequate air flow distribution among different units into the power management bay. In this sense, the bay results confirm the pedigree of the design developed, as showing adequate flow/velocity distribution, and temperature levels.
The consortium has disseminated the results in an aircraft related Conference paper, summarizing the activities and results obtained. Another contribution to a Workshop in the Thermal Management field has reflected the developments of Stage A heat sinks, and also the analysis of new material coupon samples.
The partners have identified future possibilities of exploitation for the heat sinks (one with only integrating APG, and a second one integrating APG and MMC inserts) and new materials generated during the project (a new MMC material with high thermal conductivity anisotropy which opens the possibility to exploit it in heat spreader applications).
