Abstract: A 3D unsteady state numerical model of heat transfer in the circumferential laser oxygen cutting of pipes was developed. In order to minimize the computing time required for solving the finite difference equations as much as possible, the alternating direction implicit (ADI) method was adopted. Based on the characteristics of the pipe cutting process, the periodic boundary condition was applied to calculate the temperature distribution in the θ direction and the self-adaptive grid technology was also used. The mathematical model takes account of the temperature-dependent thermal properties of the pipe. The calculated kerfs width and the heat-affected zone (HAZ) were compared with the experimental results.

Key words: Laser cutting, Pipe, Temperature field