Numerical investigation of optimal flow conditions in an optically accessed compression ignition engine

• Published in: Transportation engineering (Oxford) Vol. 2; p. 100036
• Main Authors: Lewandowski, Michał T., Netzer, Corinna, Emberson, David R., Løvås, Terese
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2020; Elsevier
• Subjects: Compression ignition; Computational fluid dynamics; Optical engine; Spray; Optical engine; Spray; Computational fluid dynamics; Compression ignition
• ISSN: 2666-691X; 2666-691X
• DOI: 10.1016/j.treng.2020.100036

•CFD analysis of the flow in an optical combustion chamber.•Assessment of RANS turbulence models.•The influence of geometrical modifications on flow characterization.•Optimal flow conditions for spray injection identified and evaluated. This study aims towards quantifying of the flow in an optically accessed compression ignition engine using computational fluid dynamic simulations. The test rig serves to investigate different fuels and allows for spray propagation observation and in-flame soot measurements. Computational fluid dynamic simulations were employed to investigate the effects of geometrical modifications in order to obtain optimal flow conditions for fuel spray injection. The flow should be quiescent enough to avoid affecting spray propagation but effectively remove flue gasses after combustion and prevent glass fouling to allow optical observations. The numerical model results are validated against experimental data for several conditions. Different turbulence Reynolds Averaged Navier Stokes (RANS) closures were assessed and briefly discussed. Three geometrical configurations of the connecting throat have been employed and the resulting flow was analyzed under motored conditions revealing favourable conditions for fuel spray injection. Finally, non-reacting, evaporating spray simulations in those configurations have been performed showing the impact of the gas flow in the combustion chamber on spray propagation.