

The necessity of integrating novel dimensionless parameters with ANN for improved correlations: an application to heat and fluid flow in 3D Lattice Metal Frames
Moghtada Mobedi
Shizuoka University, Japan
ABSTRACT
The theoretical analysis of heat and fluid flow problems originated in the 19th century through the analytical solution of Navier-Stokes and energy equations, which was expanded by 20th-century’s empirical correlations based on fundamental dimensionless numbers. However, the rise of complex applications rendered these analytical and correlational approaches insufficient. While computational methods (CFD) emerged to handle intricate geometries, the increasing complexity of modern systems (such as 3D Lattice Metal Frames) leads to prohibitively long simulation run times. This dependency on expensive and case-by-case thermal analyses necessitates a paradigm shift. This work proposes that defining novel and complex dimensionless parameters, and integrating them with advanced machine learning techniques offers the necessary breakthrough.
The study investigates convective heat transfer in a channel containing 3D LMF structures. The Nusselt number and friction factor were computationally calculated for twelve different LMF geometries such as Pin Fin, Kagome, Octahedron, and Octet. An Artificial Neural Network (ANN) model was subsequently developed using MATLAB based on these numerical results. Crucially, the model employs only six dimensionless input parameters, the Reynolds number and five other novel dimensionless parameters to define the complete geometrical features of all structures.
The developed ANN correlation successfully and accurately predicts both the Nusselt number and friction factor for all studied 3D LMF structures. This outcome verifies the primary aim: the successful development of new and complex dimensionless parameters capable of generalizing geometrical complexity. By combining these parameters with the trained ANN model, the Nusselt number and friction factor values can be determined rapidly, providing a powerful, cost-effective ANN correlation that overcomes the time limitations of traditional numerical simulation.
BIOGRAPHICAL NOTE
Dr. Moghtada Mobedi is a Professor in the Department of Mechanical Engineering at Shizuoka University in Hamamatsu, Japan. His core research focuses on Thermal Engineering, with specific expertise in heat transfer enhancement, modeling of heat and fluid flow in porous media, and thermal energy storage systems utilizing solid-liquid phase change materials. He has taught numerous bachelor, master and Ph.D. level courses at various universities across Japan, Turkey, and other European countries. Furthermore, he has supervised a significant number of master's and Ph.D. students who have since graduated and actively continue careers in academic and industrial sectors worldwide. He has contributed to the heat transfer field through his editorial work, serving as an editor for books including Solid–Liquid Thermal Energy Storage: Modeling and Applications (2022) and Advances on Heat and Mass Transfer in Porous Media (2023), and authoring Fundamentals of Heat Transfer: An Interdisciplinary Analytical Approach (2023). He has an extensive publication record, publishing over 150 scientific papers and contributed to the academic literature. He has led many projects funded by Japan Society for the Promotion of Science, Suzuki Foundation, State Planning Department of Turkey, and Scientific and Technological Research Council of Turkey to study and discover innovative methods for heat transfer enhancement in convective flows, adsorbent beds, as well as in solid-liquid phase change thermal storage. He was honored to be the plenary and keynote speaker on his research topics at numerous conferences, and is pleased to be invited to the MPSU2026 conference in Cracow, Poland to present his team’s study.
