A Novel Numerical Methodology to Simulate Unsteady Flows in ICE Manifolds

The development of high-tech engines is demanding for the analysis of complex phenomena, where microstructural dynamics, mesoscopic features or boundary singularities give multiresolution patterns. As the continuum approach is unable to represent the physics at different scales, the interest in discrete particle methods as well as lattice techniques is increasing. Among these models, particle methods at the mesoscopic level, such as Dissipative Particle Dynamics (DPD) models [1,2], are the most promising tool, as they are less demanding, from a computational point of view, than Molecular Dynamics (MD). Moreover, with respect to the lattice methods, the Galilean invariance and the isotropy are also satisfied. The versatility of DPD makes it suitable for the simulation of immiscible fluid mixtures, drop dynamic, phase separation, polymer solution, colloidal suspensions, etc. [3,4,5]. This work is intended to introduce this method in the field of automotive engineering and to show its potentiality in this area. A three-dimensional DPD code for massive computations has been developed by using the MPI protocol. The code has been applied to the simulation of intake manifolds in ICEs. Air is supposed to enter into the manifold, where the flow is driven into the combustion chambers under a pressure gradient. An original inlet-outlet boundary condition, the so-called external layers boundary condition (ELBC), is proposed and discussed. The initial results are promising and the relative simplicity of DPD modeling encourages the use of this tool for simulating even more complex flows.