The 15th ERCOFTAC workshop on Direct and Large Eddy Simulation was held in Delft, the Netherlands, on 20-22 May 2026.

The goal of the bi-annual DLES workshop series is to establish the state of the art in Direct Numerical Simulation, Large Eddy Simulation, and related hybrid techniques that resolve instantaneous flow structures either partially or fully. The range of topics addressed at DLES15 includes, but is not limited to, the following:

• advanced numerical methods and algorithms for high-performance computing;
• new models for transition, turbulence, heat and mass transfer, reactive flows and multiphase flows;
• new fundamental theories based on insights from DNS and LES;
• methods for data analysis, data assimilation, and reduced order modelling, including machine learning;
• applications of DNS, LES and hybrid methods in engineering, biological, environmental, and geophysical flows.

This gathering of specialists offers a unique opportunity to discuss recent advances in the prediction, understanding, and control of turbulent flows in both academic and industrial applications.

We gratefully acknowledge the support of: