Resin transfer moulding (RTM) is a production method used for the manufacture of continuous fibre-reinforced thermoset composites for aerospace, automotive, marine and civil applications. Production of large and thick composite structures is becoming increasingly essential, hence the simulation of composite processing is seen as a key design tool in the efforts to enhance efficiencies and improve product quality. This thesis addresses some of the key flow parameters in the resin transfer moulding process. The flow parameters studied are; resin viscosity, curing behaviour, flow front progression and micro scale flow filling properties. Rheological characterisation studies were performed on typical RTM resins as very little information exists on these systems. In addition to the characterisation studies, a model has been proposed for the advancement of the rheology during cure. This model is based on viscosity-time experimental measurements taken at constant temperature. The key advantage of this model compared with most other proposed models is that it is not explicitly dependent on the extent of cure. Velocity field analysis studies were conducted by micro-scale simulation of the influx of resin into the mould by visualising flow through a Perspex cell with a hexagonal arrangement of rods. A model fluid whose refractive index was matched with the Perspex was used in this study. The local velocity fields were analysed by taking images of the fluid flow seeded with aluminium dust. Micro-scale flow front tracking experiments were conducted using the Perspex flow cell in order to characterise the shape of the flow front during filling in RTM. Finally, experiments were conducted using the SMARTWeave flow monitoring system to determine the progression of the flow front for different fibre fill scenarios. The experiments were carried out on an industrial scale mould at QinetiQ^a.