This Special Issue contains 14 papers selected from a total of 153 papers presented at the Twelfth Mediterranean Combustion Symposium (MCS12), jointly co-sponsored by the Combustion Institute, the International Centre for Heat and Mass Transfer, and the Egyptian Society for Renewable Energy and held in Luxor-Egypt during the period 22–26 January 2023. The aim of the Symposium was to give combustion scientists, engineers and students based predominantly in Mediterranean countries an opportunity to get together with colleagues from other global regions, to discuss and disseminate state-of-the-art research and recent advances in the field of combustionand to enhance future collaborative research activities between scientists from different countries in the region. This Special Issue is the sixth in the series, the series having started with the Seventh Mediterranean Combustion Symposium.

Following a preliminary selection by the editors of a subset of Symposium papers, with quality and fit to Journal scope being the principal criteria, the papers were then subjected to a rigorous peer-review process by three expert reviewers, as applied to any standard submissions to the Journal. This process was therefore independent from the review of the original conference submissions.

The Guest Editors are grateful for the opportunity to publish this Special Issue, and they hope that it will be regarded as a valuable contribution to the field of turbulent combustion of gaseous and liquid fuels.