Two-dimensional CFD modelling of flow round profiled FSW tooling

This paper describes the application of the computational fluid dynamics (CFD) code, FLUENT, to modelling the two-dimensional metal flow in friction stir welding (FSW). The primary goal is to assist in the development of new welding tools, though the models also improve the understanding of the deformation mechanism in FSW, and enable a first order visualisation of the flow round the probe. The paper describes a quantitative method of comparing the flow round different tool shapes. A novel ‘slip’ model was developed, where the interface conditions were governed by the local shear stresses. This revealed significant differences in behaviour when compared with the common assumption of material stick. The two-dimensional model has demonstrated the viability of the approach for investigating the flow round practical tool shapes, and gives confidence that the development of more computer intensive three-dimensional models will be justified.