Resin infusion is a pressure-gradient-driven composite manufacturing process in which the liquid resin is driven to flow through and fill in the void space of a porous composite preform prior to the heat treatment for resin solidification. It usually is a great challenge to design both the infusion system and the infusion process meeting the manufacturing requirements, especially for large-scale components of aircraft and wind turbine blades. Aiming at addressing the key concerns about flow fronts and air bubble entrapment, the present study proposes a modelling framework of the multiphase flow of resin and air in a dual scale porous medium, i.e. a composite preform. A finite strain formulation is discussed for the fluid–solid interaction during an infusion process. The present study bridges the gap between the microscopic observation and the macroscopic modelling by using the averaging method and first principle method, which sheds new light on the high-fidelity finite element modelling.

树脂灌注是压力梯度驱动的复合材料制造工艺，其中在树脂固化的热处理之前，驱动液态树脂流过并填充在多孔复合材料预成型坯的空隙中。设计满足制造要求的输液系统和输液工艺通常是一个巨大的挑战，特别是对于飞机和风力涡轮机叶片的大型组件而言。为了解决与流动前沿和气泡截留有关的关键问题，本研究提出了在双尺度多孔介质（即复合材料预成型坯）中树脂和空气多相流动的建模框架。讨论了输液过程中流体与固体相互作用的有限应变公式。