Fluid Dynamics and Structural Behavior of Optimized Combustion Chamber Profiles

The present investigation describes an all-embracing methodology to design the combustion chamber profile of direct injection diesel engines with the help of computer simulations. The first step of the method is the creation of a parametric profile of the chamber by using Bezier curves. In the present investigation two Bezier curves were considered with five end points and four control points. In the second step, the Bezier profile is used to define the mesh for the CFD calculation with CFX 5.0 and the piston shape for Ansys V 11.0 by automatically writing the profile in the input files for the pre-processor. In the third step a run with CFX is performed to evaluate the behaviour of the chamber in terms of performance, fuel consumption and pollutant emissions. Then, the temperature and pressure distributions along the chamber profile are used in the framework of the CFX -Ansys model to assess the structural behaviour of the chamber. Finally, the performance, emissions and structural characteristics of the chamber are summed up in two output files. Note that this methodology has been designed to be integrated in a multi-objective optimization environment in order to find the chamber profile best suited to the designer needs.