The increase of reliability of high-speed electrical machines is a crucial goal in the industrial point of view. The use of electrical equipment undergoing hard operating conditions (rotational speed, heat dissipations) leads to the development of efficient, passive and reliable device, capable of extracting heat from those systems. As well as being an excellent passive system transferring large quantities of heat, the axial rotating heat pipe satisfies all requirements because of its reduced size and small working fluid loads.

First, we proposed the improvement of existing experimental set up to characterise these two phase-flow devices operating under very high radial acceleration levels. Many parameters are involved in the behaviour of such a complex system: inside geometry, nature and charge in two-phase fluid and external surroundings (transient dissipations, range of temperature of cold source...). Evaporator dissipations were provided by induction while cooling of condenser achieved by air flow in existing high security area. Temperature evolutions of wall heat pipe were measured by Infra-red cameras and heat balances were made at several levels (inductor, heat pipe, cooling air flow…). Different filling ratios and geometry heat pipes were investigated to get deep understanding of heat transfer performances from low to high rotational speed.

In the same time and after a strong state of the art of the modelling of transfer in heat pipe at high rotational speed, numerical modelling was performed at different levels: microscopic liquid/vapour level (finite volume model) then at system level by building and validate nodal networks to reach the objective of certifying the performances of each model approach versus experimental results.

Thanks to these developments, we were able to propose optimisation of high rotational heat pipes for heat transfer in motorised turbomachine context.