The problem of finding a fluid for two phase capillary pumped cooling systems is a multiobjective one, considering the numerous properties to match. Besides we can expect to find a fluid within the tens of thousands of existing molecules, which have not been tested for this application, or a fluid that could be easily synthesised from an existing fluid. The critical point is finding the fluid among databases and/ or identifying chemical functions that would enable an existing fluid to match the specifications. Finally, we can expect mixtures to be suitable as much as pure fluids.

Rather than undertaking an inefficient trial and error search, we proposed to implement a computer aided molecule and mixture design approach based on reverse engineering. Such a strategy combines bottom-up and top-down approaches to find fluids that can match a large set of specification together.

The first task (WP1) consisted in building a mathematical performance function encompassing all the property specifications and screen potentially interesting chemical families. Second, a systematic computer-based search was run to issue a list of candidate fluids (WP2). It combined two existing computer tools from the partners: a bottom-up approach to account for feasible chemical synthesis pathways, and top-down search based on group contribution property estimation methods to explore new pure compounds and mixtures. Third, the candidate list was narrowed by refining property calculations by using accurate first principle methods (WP3). They also provided an electronic signature of the ideal fluid. The fourth task concerned the fluid choice and is possible synthesis (WP4). Fifth, experimental measurements were performed to validate a few candidates (WP5).