Speakers
Description
Heat pipes have become key thermal management solutions for a wide range of applications where efficient and passive heat transfer is required. They are widely used in electronic cooling systems, such as computer processors and power electronics, as well as in aerospace and satellite systems, where reliability and compactness are critical. Among the different types, loop heat pipes (LHPs) are particularly attractive due to their ability to transport heat over long distances, operate against gravity, and provide high thermal performance without moving parts.
LHPs are commonly employed in space and aeronautical applications for the cooling of electronic equipment, where space constraints, weight limitations, and high heat fluxes impose stringent design requirements. Their main advantages include high effective thermal conductivity and robust operation under varying thermal loads and orientations.
In this context, the von Karman Institute (VKI) is involved in the LHP4ebox project, funded by the Skywin programme, which aims to develop a new generation of loop heat pipes integrated directly into the core of electronic equipment, using additively manufactured porous materials in the evaporator section. These advanced porous structures are expected to enhance capillary performance and improve heat transfer capabilities, while minimizing space requirements.
One aspect that remains largely unexplored is the influence of acceleration on LHP performance. In aeronautical environments, accelerations of up to several times the gravitational acceleration can occur, potentially affecting the distribution of liquid and vapor phases within the heat pipe and, consequently, its thermal behavior.
To address this challenge, the project will develop a dedicated experimental setup capable of reproducing acceleration levels representative of aeronautical conditions (up to 2g). A key feature of this setup is the integration of infrared thermography. While the most used measurement technique for such systems mostly consists in pointwise measurements using thermocouples, infrared imaging enables non-intrusive, spatially and temporally resolved measurements of surface temperature fields, providing indirect but valuable insight into phase distribution and flow regimes within the heat pipe. Its application has already demonstrated strong potential in the study of pulsating heat pipes. In this work, existing infrared methodologies developed for loop heat pipes will be adapted to consider the porous structures in the evaporator, enabling enhanced characterization of phase distribution.
The combination of controlled acceleration testing and high-resolution infrared thermography is expected to provide a deeper understanding of LHP operation under realistic conditions, ultimately supporting the development of more robust and efficient thermal management solutions for aeronautical applications.
