ENCOM 3 - Enhanced Condensers in Microgravity

Marengo, Marco and Miche, Nicolas and Georgoulas, Anastasios (2021) ENCOM 3 - Enhanced Condensers in Microgravity. [Data Collection]

Project Description

Condensation is encountered in many engineering fields (energy conversion, chemical, pharmaceutical and food industries) and, particularly, in space applications. There is, consequently, a great diversity of situations in which condensation processes are present and must be well understood. The proposed research will focus on fluid-dynamics effects in two-phase vapor/liquid based heat transfer devices with an emphasis on condensation process enhancement and overall efficiency of the two-phase systems improvement. In a reduced gravity environment the applications include the life support systems, the thermal management systems for satellites, the energy production and power managements systems for long time missions or manned space platforms, waste water treatment for long duration space exploration missions and fluid management from the storage tanks through the lines to the engine. The proper design of such systems under microgravity conditions and variable gravity conditions requires to be able to predict the flow patterns, the pressure drop and the heat transfer coefficients. Besides, the knowledge of the gravity effect can provide key information for the design and optimization of condensation devices also in ground environment. It is quite evident that the combined effects of phase change, instabilities, thermocapillarity, interface thermal resistance, gas dynamics, gravity, as well as wettability are somewhat complicated issues. In particular, the study of surface wettability opens nowadays a wide range of possibilities for heat transfer enhancement in the condenser. Condensers have different behavior on earth and in microgravity conditions. The heat transfer enhancement of the condenser part of LHP, CPL and HP is needed due to the continuous increase of the heat dissipation on the satellites. Correlations used to design condensers for space applications have been developed and tested only in the ground conditions. By performing experiments in space without the interference of gravity, it is possible to provide the basics required to formulate precise models and support the optimisation of system designs. The proposed research project will be directly in support of the definition of experiments for the Thermal Platform (Condensation on Fins and In-tube Condensation) where phase change and two-phase flow phenomena are studied. The main objectives of the ENCOM-3 Proposal are the following: 1. To achieve a new fundamental understanding of the condensation phenomena using the multi-scale theoretical and experimental approach. 2. To improve knowledge of physics of two-phase flow with phase change in microgravity. 3. To study the effect of surface wettability on condensation in absence of gravity effects. 4. To study the possibilities of heat transfer enhancement in microgravity 5. To advance the numerical capabilities in predicting the condensation phenomena at different gravity levels. To achieve the aforementioned objectives three main topics have been identified. The purpose for each topic is to correlate the results obtained on-ground, both experimental and theoretical, with those obtained in microgravity conditions. To realize this goal, parabolic flight experiments are planned in preparation of microgravity experiments on Thermal Platform. Understanding and modeling the basic mechanisms of condensation will improve the efficiency of heat transfer devices both for ground and for space applications. Moreover, the project is built in such a way to promote strong collaboration among the partners from Universities and Industry, connecting specialists from both the environments. The collaboration is fundamental to gain useful deep knowledge related to the mechanisms controlling condensation but, also, to orient the present research to possibly achieve some significant technological improvement. The present consortium is, thus, based on three cornerstones: • Inclusion of different groups working already in this research topics which have effectively demonstrated a number of fruitful collaborations. • Integration of sophisticated complementary equipment and facilities for elaborated experiments with powerful theoretical techniques. • Close collaboration between strong research groups and industrial laboratories, which will lead to achieve practical solutions to real problems.