Document Type
Article
Journal/Book Title/Conference
AppliedMath
Author ORCID Identifier
Zilong Song: https://orcid.org/0000-0002-2823-199X
Volume
6
Issue
9
Publisher
MDPI AG
Publication Date
9-5-2026
Journal Article Version
Version of Record
First Page
1
Last Page
29
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.
Abstract
Friction stir welding (FSW) is a solid-state manufacturing process widely used in joining aluminum and other metal workpieces. The FSW process can be modeled by a coupled system of non-Newtonian Navier–Stokes and heat-transfer equations. However, solving this non-linear system with high accuracy requires significant computational power. This work refines the system by introducing corrected coefficients and new treatments for boundary conditions near the tool. Then, model order reduction, including the Proper Orthogonal Decomposition (POD) and Discrete Empirical Interpolation Method (DEIM), is applied to efficiently solve the FSW system in a low-dimensional space. To enhance accuracy and effectiveness, two novel treatments have been adopted for the POD and DEIM models: the introduction of preconditioner matrices to avoid large condition numbers and the use of indicator matrices to generate the non-linear data. For different cases regarding operating parameters, the results show that the DEIM model dramatically speeds up the computation (e.g., over 250 times faster compared with the full model) while maintaining accuracy. This makes simulations of the FSW process more accessible and easily combined with machine learning techniques in future study.
Recommended Citation
Kay, J.; Song, Z. Fast Computation and Model Order Reduction of the Friction Stir Welding Process with POD-DEIM. AppliedMath 2026, 6, 148. https://doi.org/10.3390/appliedmath6090148