Semi-analytic approximation of the temperature field resulting from moving heat loads

•A novel semi-analytic approximation for 2D moving heat source problems is proposed.•The approximation decouples the 2D problem into three 1D problems.•In a wafer heating example the approximation reduces the computational time by 90%.•The approximation is also applicable to 3D spatial domains. Moving heat load problems appear in many manufacturing processes, such as lithography, welding, grinding, and additive manufacturing. The simulation of moving heat load problems by the finite-element method poses several numerical challenges, which may lead to time consuming computations. In this paper, we propose a 2D semi-analytic model in which the problem in two spatial dimensions is decoupled into three problems in one spatial dimension. This decoupling significantly reduces the computational time, but also introduces an additional error. The method is applied to a wafer heating example, in which the computational time is reduced by a factor 10 at the cost of a 4% error in the temperature field.