Purpose – The purpose of this paper is to describe a model that can be used in the estimation of thermal fatigue limited service life of induction coils. Design/methodology/approach – Previous work indicates that the temperature of the cross section of an induction coil can be used to estimate thermal fatigue limited service life. This paper presents a model for estimating these temperatures based on a coupled model. Joule losses modelled in Flux2D are coupled with cooling modelled in Fluent3D. These models are controlled and combined by Python scripts that iterate the heat transfer and temperatures of heat exchange regions between the two domains. Findings – The combined model is shown to converge nicely. The model is also applied to an optimization problem where a high power loss, copper region is surrounding a wedge‐shaped cooling channel. The point of the wedge was replaced by a radius that was optimized. The optimum was considered where the thermal fatigue service life is maximized, i.e. where the peak deviation from mean temperature in the cross section was at a minimum. The results show that the optimum corner radii are small, typically 0.25‐0.5 mm. Originality/value – This is the first paper where the full model is presented and used to optimize specific cases.
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering – Emerald Publishing
Published: Sep 13, 2011
Keywords: Modelling; Coils; Thermal properties of materials; Fatigue