Novel Hybrid Heat Pipe for space and ground applications

Marengo, Marco and Miche, Nicolas and Georgoulas, Anastasios and Andredaki, Manolia and Mangini, Daniele and Pietrasanta, Luca (2021) Novel Hybrid Heat Pipe for space and ground applications. [Data Collection]

Project Description

Industry demand for high heat transfer capability, efficient thermal control, flexibility and low cost has motivated researchers to develop a new generation of passive systems mainly based on fluid phase-change. This project proposes the modelling and the experimental characterisation of a novel wickless heat transfer device applicable both on the ground and in space. The name Hybrid Heat Pipe (HyHP) comes from the fact that the well-established loop thermosyphon (TS) is here transformed to a plain serpentine device with one evaporator for each turn, as a pulsating heat pipe (PHP). Why do we need a new wickless heat device? Two-phase heat transfer devices play an important role in a variety of engineering fields; TSs, for example, are already successfully implemented in nuclear and solar plants, while heat pipe applications range from electronics cooling to the automotive sector. But the actual systems have two major problems: 1) dissipation of high thermal powers maintaining high heat fluxes has significant limits connected to the upscale of the internal wick and the system dimensions, 2) the deployability or the flexibility of the passive two-phase systems is quite reduced. How does HyHP work? The vertical operation in gravity, as well as the distinctive location of the heating and the cooling sections, causes the fluid to circulate regularly in a preferential direction guaranteeing stable operation and homogeneous temperature distribution of the system. The combination between channel dimension and working fluid is chosen in such a way that the device will operate in thermosyphon mode on the ground and, in the case of weightless conditions, in capillary mode, i.e the liquid completely fills the tube section and therefore vapour expansion and contraction cause an oscillation of the liquid/vapour patterns. Why do we need a new project on HyHP? Because, although in 2014 a first HyHP prototype was built and the first ground and microgravity experiments were successfully carried out, we are far from understanding all the physical phenomena inside a HyHP and our ability to simulate the processes involved is still quite limited, i.e. we are not able to design a HyHP to manage heat within given boundary conditions. Numerical analyses are fundamental to understanding the possible advantages and drawbacks of the HyHP and to predict its performance. The development and the use of innovative numerical tools and theoretical approaches will provide an insight into the physical phenomena and the governing mechanisms of a HyHP, opening the route to more efficient and customised design. These numerical studies will be supported by parallel extensive experimental campaigns. A prototype with an Infrared (IR) and Visible Spectrum (VIS) window will be designed, built, equipped with several sensors and tested both on the ground and in micro-gravity conditions. ESA has already offered us partial funding and access to the parabolic flight campaigns. It is expected that the primary beneficiary of this research will be the space industry; however advantages are not confined to this specific field, as the support of two ground-based companies indicates. Since the novel design of HyHPs combines technological aspects from both TSs and PHPs, the numerical tools we develop will be relevant to all industries concerned with thermal management. The investigation will benefit the scientific and industrial sectors by providing an open-source CFD tool for the simulation of general phase-change heat transfer phenomena. Finally the project is contributing to the growing of the new Advanced Engineering Centre of the University of Brighton, which starts with a initial investment of £14M with the aim of delivering world leading research in the sectors of Internal Combustion Engines, Thermal Efficiency and System Efficiency, and Thermal Management for Ground and Space Applications.