• Bodaghi, M.
• Pina, L.
• Gomes De Almeida, F.

Abstract

This paper describes the influence of variable inlet pressure on the flow front position and velocities in a one dimensional vacuum infusion process. To do so, a set of experiments was carried out at INEGI's Vacuum Infusion Laboratorial System, using epoxy resin and a random glass fibre mat. These experiments were devised to capture the influence of several variables of interest in this phenomena. The observed data was obtained by pressure sensors, to measure the pressure at relevant locations and a digital video camera to detect the flow front position at each time instant. The data shows a dynamical behaviour of the infusion process that cannot be modelled using the traditional quasi-steady-state equations. Hence, there is a need to consider relevant dynamical phenomena like capillary pressure and nonlinear pressure gradient inside the fluid. The analysis of the obtained data reveals the relative influence of the various phenomena and provides critical information for the subsequent modelling attempts. A system identification approach was performed to fit a linear dynamical system to each of the infusion process phases. The non-linear nature of vacuum infusion processes, as they are ruled by the Darcy's law, optimal approximations in the Least Squares sense were obtained. The study of these phenomena is expected to provide further insight on the dynamical behaviour of vacuum infusion processes with direct implications on the dynamical models that can be used for real-time control of such industrial processes.

Topics

• impedance spectroscopy
• phase
• experiment
• glass
• glass
• random
• resin