Parallel simulation of combustion in Common Rail Diesel engines by advanced numerical solution of detailed chemistry

In the last years the in-cylinder 3d combustion models have been focused on the emission predictions, using detailed combustion chemistry. In this paper, we discuss the integration of a detailed combustion chemical kinetic model into the unsteady compressible Navier-Stokes one used by KIVA3V-II code, in order to simulate a Common Rail FIAT 1.9 JTD Diesel engine. For solving the detailed chemistry, we developed a parallel software package based on a SPMD programming model, where the processes solve concurrently the subset of ODE systems, modeling chemical kinetic, on subgrids of the overall computational grid. Each ODE system is sequentially solved by using the well-known VODE software package, implementing automatically adaptive implicit methods. In this context, load balancing is a critical issue, depending on the stiffness of the equations under the local conditions. In this paper, we analyze performance results of realistic parallel simulations when different grid partitioning strategies are used.