Open Access

ARTICLE

Lattice Boltzmann-Based Numerical Simulation of Laser Welding in Solar Panel Busbars

Dongfang Li¹, Mingliang Zheng^2,*

1 School of Mechanical and Electrical Engineering, Quzhou College of Technology, Quzhou, 324000, China
2 School of Mechanical and Electrical Engineering, Huainan Normal University, Huainan, 232038, China

* Corresponding Author: Mingliang Zheng. Email:

(This article belongs to the Special Issue: Model-Based Approaches in Fluid Mechanics: From Theory to industrial Applications)

Fluid Dynamics & Materials Processing 2025, 21(8), 1955-1968. https://doi.org/10.32604/fdmp.2025.069254

Received 18 June 2025; Accepted 30 July 2025; Issue published 12 September 2025

Abstract

To address the limitations of traditional finite element methods, particularly the continuum assumption and difficulties in tracking the solid-liquid interface, this study introduces a lattice Boltzmann-based mathematical and physical model to simulate flow and heat transfer in the laser welding molten pool of tin-coated copper used in solar panel busbars (a thin strip or wire of conductive metal embedded on the surface of a solar cell to collect and conduct the electricity generated by the photovoltaic cell). The model incorporates key external forces, including surface tension, solid-liquid interface tension, and recoil pressure. A moving and rotating Gaussian-body heat source is adopted, with temperature treated as an implicit function of enthalpy. Coupled iterative schemes for the temperature and velocity fields are constructed using a dual-distribution function approach with a D3Q15 lattice structure. The model is implemented in Python, utilizing libraries such as NumPy, SciPy, Mayavi, and Matplotlib for computation and visualization. Simulation results reveal that the heat transfer mechanism in the molten pool transitions from pure conduction to conduction-convection due to surface tension effects, leading to the formation of multiple counter-rotating vortex structures. The peak temperature at the pool center reaches 3200 K, with maximum melt depth and width measured at 0.5 and 1.2 mm, respectively. Over time, both penetration depth and melt width increase, though the width exhibits a more pronounced growth. Comparison with experimental thermal cycling data from laser weld joints shows strong agreement, with a maximum error of less than 1%, validating the accuracy of the proposed method.

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