Computational fluid dynamics-derived correlations for power transformer thermal-hydraulic performance prediction

• Type: Article in International Scientific Journal
• Date: 2026-02

Authors

Sandra Couto (Author) Other; Diogo P. Gonçalves (Author) Other; Marta Santos (Author) Other; Soraia Neves (Author) FEUP; M.C.F. Silva (Author) FEUP

Journal

Title: Electric Power Systems Research

Vol. 255

Pages: 1-12

ISSN: 0378-7796

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

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ALiCE - ALiCE - Laboratório Associado em Engenharia Química

CEFT - CEFT - Centro de Estudos de Fenómenos de Transporte

GAI4FD - Metodologia de Avaliação para modelos de Super-Resolução de Inteligência Artificial Generativa para Dinâmica de Fluidos

ECO-MOBES - Mobilidade Inteligente & Tecnologias para a Eficiência de Recursos

Other information

Authenticus ID: P-01B-849

DOI: 10.1016/j.epsr.2026.112832

Abstract (EN): The cooling performance of power transformer (PT) windings depends on both fluid properties and winding geometry. This study performed 108 steady-state CFD simulations on a core-type, oil-directed PT to assess different axial (6-8 mm) and radial (4-6 mm) channel dimensions with mineral oil and natural esters across multiple Reynolds numbers. Numerical predictions were validated against experimental data, confirming the accuracy of the simulations. Results showed that pressure drop trends were unaffected by heat transfer and correlated well with fluid properties under isothermal conditions. Transformer thermal performance was mainly influenced by Reynolds number and axial channel width; natural esters produced lower winding temperatures than mineral oil, but at a higher-pressure drop. Using a porous-bed flow analogy, new correlations were developed for pressure drop and winding-to-oil temperature gradients, achieving deviations below 0.7% and 1.8 degrees C, respectively. These correlations provide accurate and computationally efficient alternatives to CFD during design, supporting both new transformer development and retrofitting with alternative fluids.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12