SIMAI 2025

Mapping CFD Simulations to ML Convolutions

  • Saetta, Ettore (University of Naples Federico II)
  • Paolino, Antonello (University of Naples Federico II)
  • Tognaccini, Renato (University of Naples Federico II)
  • Pucci, Daniele (Italian Institute of Technology)
  • Iaccarino, Gianluca (Stanford University)

Please login to view abstract download link

In the age of Machine Learning, data-driven reduced-order models (ROMs) are gaining attraction across numerous scientific disciplines. Convolutional Autoencoders, in particular, met considerable success for both data compression and surrogate modeling [1]. When handling scientific datasets, model architectures are often tailored to the data’s underlying structure (e.g. graph neural networks for unstructured computational grids, and convolutional networks for structured data). While standard convolutional layers offer computational efficiency and straightforward training, their applicability is inherently limited to data organized on regular grids [2]. However, Computational Fluid Dynamics (CFD) simulations of complex geometries, are typically performed on unstructured meshes, which cannot be directly processed by such layers. In this presentation, we introduce three methods to deal with unstructured CFD surface data: (i) current most adopted procedure of direct interpolation of unstructured data onto a predefined structured grid, (ii) the use of a conformal mapping technique [3] to transform unstructured CFD meshes into structured computational domains and (iii) a grid mapping based on the shortest distance path of the computational graph built on the CFD grid. Pros and cons of each algorithm will be discussed. The method will be applied to CFD solutions on swept wings, varying the sweep angle and the angle of attack. [1] Kamal Berahmand and Fatemeh Daneshfar and Elaheh Sadat Salehi and Yuefeng Li and Yue Xu, Autoencoders and their applications in machine learning: a survey. Artificial Intelligence Review (2024) 57:28. https://doi.org/10.1007/s10462-023-10662-6. [2] Ettore Saetta and Renato Tognaccini and Gianluca Iaccarino, Machine Learning to Predict Aerodynamic Stall. International Journal of Computational Fluid Dynamics (2022), Vol. 36, n. 7, pp. 641-654. https://doi.org/10.1080/10618562.2023.2171021. [3] Zhiyuan Lyu and Lok Ming Lui and Gary P. T. Choi, Spherical density-equalizing map for genus-0 closed surfaces. SIAM Journal on Imaging Sciences 17.4 (2024): 2110-2141.