Numerical and optical soot characterization through 2-color pyrometry technique for an innovative diesel piston bowl design

[EN] The development of innovative diesel piston bowl designs has shown significant improvement of the near-wall flame evolution, resulting in lower fuel consumption and engine-out soot emissions. With this aim, a novel hybrid piston bowl for a 1.6 L light-duty diesel engine was designed, coupling a...

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Detalles Bibliográficos
Autores: Piano, A., Roggio, S., Millo, F., De Vargas Lewiski, Felipe, Pesce, F. C., Vassallo, A., Bianco, A., García Martínez, Antonio|||0000-0001-5783-4936, Micó, Carlos|||0000-0001-5787-6212
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/212071
Acceso en línea:https://riunet.upv.es/handle/10251/212071
Access Level:acceso abierto
Palabra clave:Innovative diesel engine piston bowl
Optical engine
2-Color pyrometry technique
Computational Fluid Dynamics
Numerical optical soot density KL
MAQUINAS Y MOTORES TERMICOS
Descripción
Sumario:[EN] The development of innovative diesel piston bowl designs has shown significant improvement of the near-wall flame evolution, resulting in lower fuel consumption and engine-out soot emissions. With this aim, a novel hybrid piston bowl for a 1.6 L light-duty diesel engine was designed, coupling a sharp-stepped bowl and radial-bumps in the inner bowl rim. The effects of the proposed hybrid bowl were analysed through both single-cylinder optical engine and 3D-CFD models, which feature a detailed chemical kinetic mechanism and the Particulate Mimic (PM) soot model. The 2-color pyrometry optical technique was adopted to obtain the optical soot density (KL) and the temperature of the soot surface. Then, a line-of-sight integration of the numerical soot distribution was adopted to obtain a planar KL distribution, which is directly comparable with the experimental KL images. The results showed a good agreement in terms of soot distribution between 3D-CFD and experiments, confirming the high prediction capabilities of the developed numerical methodology. The synergetic application of numerical and optical techniques highlighted that the hybrid bowl strongly mitigates the flame-to-flame interaction with respect to a conventional re-entrant bowl, leading to lower soot formation in the flame collision area. Moreover, faster flame propagation toward the cylinder axis is highlighted with a consequent higher soot oxidation rate in the late combustion phase.