Simulation of heat transfer in fibrous insulation materials
As the demand for lightweight fibrous insulation materials in aerospace [1] and automotive [2] applications increases due to their benefits in reducing carbon footprints and costs [3], accurate prediction of thermal properties becomes crucial, particularly before production. The thermal performance of fibrous materials is highly dependent on their structural characteristics [4]. Therefore, our research aims to develop an efficient and accurate multi-physics Finite Element Method (FEM) to predict the thermal performance of these materials based on structural factors. Our work is grounded in a solid theoretical foundation [5-7], allowing us to systematically progress from key parameters, such as fibre diameter and network porosity, to 2D fibrous networks, and finally to fully realized 3D models. To achieve this, we applied the Monte Carlo method to simulate and optimize these structural parameters. COMSOL Multiphysics® (including Heat Transfer and Fluid Flow Modules) is then used to simulate complex multi-physics interactions incorporating heat conduction in both solids and gases, convective buoyancy flow in gases, radiation within the medium, and surface-to-surface radiation, with a focus on high-temperature environments. The CAD Import Module is also used to integrate realistic material structures into the simulations. The Application Builder accelerates the simulation process and facilitates easy distribution to collaborators. Our study explores three distinct 3D fibrous material models, with variations in a matrix of fibre diameter, network porosity, and material interaction properties, to comprehensively evaluate heat transfer mechanisms and performance across a range of high working temperatures. Our models have been validated through independent tests, and several structure-property relationships have been identified. This research provides valuable insights into optimizing fibrous insulation materials for high-temperature applications, contributing to the advancement of lightweight, sustainable insulation solutions.
