A study on computational fluid dynamics simulation of friction stir welding

Friction stir welding is a new technology which makes it possible to join two materials at a solid-state. The welding is performed by a non-consumption tool which rotates at a high speed to generate the frictional heat. The tool consists of a shoulder and a pin, and it is inserted into the work pieces and moves at a constant speed along the welding line. By this method, it is able to weld some hard-to-weld materials, such as aluminum alloy, magnesium alloy and dissimilar materials. Nowadays friction stir welding is mainly used for vehicles like vessel, aircraft, railcar and automobile. In this paper, a three dimensional numerical model is constructed for a simulation of the friction stir welding process using a commercial computational fluid dynamics code "Fluent". Through this simulation, asymmetric temperature distribution of advancing side and retreating side is calculated and compared with experimental results. A case study is performed to investigate an effective diameter of rotation affected cell zone in the CFD simulation.