Parametric Analysis of Piston Bowl Geometry and Injection Nozzle Configuration using 3D CFD and DoE

In meeting the stringent emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through 3D CFD simulations, this article shall parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system. After validation of the 3D simulation model with experimental results, a Design of Experiment (DoE) method shall be applied to analyze a matrix of piston bowls with parametric variations in geometry. Further, the influence of the nozzle cone angle, hydraulic flow rate, number of holes and their combination shall be determined using systematic parameter variations with selected piston bowl designs. The performance of the various hardware configurations would be evaluated based on the exhaust emissions and fuel consumption values. The combustion system under consideration is the Advanced Heavy Duty Combustion System (AHDCS) developed by FEV, which employs a narrow cone angle and a deeper piston bowl. Very high rail pressures and highly cooled Exhaust Gas Recirculation (EGR) strategy shall be used to exploit the full potential of the combustion system. An understanding of the phenomenological behavior of the spray-bowl interaction based on this parametric analysis would lay the groundwork for further optimization of the combustion system.