A Study of Flow and Phase Change in Porous Media: CFD Simulations and Experiment Design
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Authors
Pandey, Nishan
Issue Date
2018
Type
Thesis
Language
Keywords
ANSYS Fluent , LHP , Parasitic Heat Flux , Phase Change , Porous Media
Alternative Title
Abstract
NASA space systems have continuously experienced evolution in different aspects of the technologies used for the overall mission goal. To keep up with the increased capability and performance of the systems used, there is a need for developing better thermal control systems to manage the thermal needs. Current thermal control systems, mechanically pumped single-phase cooling loops, work on the principle of sensible heating and cooling. Increased precision and amount of thermal management requirement is difficult to handle by using such single-phase cooling systems. Loop Heat Pipes (LHP), working on the principle of phase-change of coolant to extract heat from a hot surface are the way forward. LHPs are smaller in size than single-phase systems while easily being able to maintain the required isothermality of the heat generating devices. In this work, a computational study on different aspects of flow and phase change in a portion of the LHP evaporator wick is conducted. Different computational simulations were carried out for a portion of the wick to better understand the heat transfer and flow patterns in the porous wick. A study on parasitic heat flux was conducted by using the results of computational simulations. An experimental setup is also designed to visualize the flow and phase-change in a porous media. A porous stainless steel sample was produced using loose powder sintering method. ANSYS Fluent is used as the computational platform.