Speaker
Description
The roll-out of highly dissipative active antennas is now a major and critical challenge which requires efficient thermal control systems. However, the collection and transport of the dissipated power are a tough problem because of several severe constraints: high heat flux density, high number of sources, high total power and complex accommodation. Several two-phase solutions are already used or are usable to overcome this issue, for instance it is possible to have a combination of HPs and LHPs (current Telecom baseline), or heat pipes connected to a standard two-layer stacked heat pipes. Nevertheless, another promising option appears to be interesting: the two-phase heat transport equipment (TPHTE) made by additive layer manufacturing (ALM). Indeed, it presents attractive advantages: the use of additive manufacturing as advanced manufacturing technique extends the possibility both in terms of geometry (for integration and accommodation) and of performances (the equipment can be structural, mechanically speaking, and it is possible to have both grooves and a micro-porous media inside to improve the thermal behaviour).
Concretely, an engineering model (EM) of a two-phase heat transport equipment has been designed, 3D-printed and tested. The present product has been designed for compact active antenna, but the same design philosophy can be adapted for other use cases.
The evaporator side is more or less 30x35 mm in section. It includes a porous media with a pore size lower than 20 µm. The overall TPHTE length is 830 mm (evaporator + condensers on both sides). Such an important length for an ALM part has been made possible by welding. As a matter of fact, two parts of ~415 mm have been welded together. The fluidic continuity has been insured by a dedicated assembly and welding process. Furthermore, there are a total of 3 cavities so as to assess the redundancy. And last, but not least, brackets have been printed at the same time than the TPHTE itself.
The EM testing assessed the technology validity over a large range of power (up to 1000 W) and heat flux density (28 W/cm²). In terms of mechanical performances, the TPHTE underwent QS test up to 40 g, Sine test up to 24 g and random test up to 23 gRMS. During the tests the TPHTE bore additional masses to simulate the active antenna amplifiers mass.
