Development and Application of a Quasi-3D Model for the Simulation of Radial Compressors of Turbochargers for Internal Combustion Engines

In this work the 3Dcell method, a quasi3D approach developed by the Internal Combustion Engine Group at Politecnico di Milano, has been extended and applied to the fluid dynamic simulation of turbocharging devices for internal combustion engines, focusing on the compressor side. The 3Dcell is based on a pseudo-staggered leapfrog method applied to the governing equation of a 1D problem arbitrarily oriented in space. The system of equations is solved referring to the relative system in the rotating zone, whereas the absolute reference system has been used elsewhere. The vaneless diffuser has been modelled resorting to the conservation of the angular momentum of the flow stream in the tangential direction, combined with the solution of the momentum equation in the radial direction. Source terms due to the presence of the centrifugal force field and its potential have been included both in the energy and momentum conservation equations to account for the interaction of the fluid with the moving blades. The model has been validated against measurements carried out on a steady state flow test bench at the University of Genoa. Once the model has been validated, a 1D use case of a turbocharged internal combustion engine has been built to evaluate the potential benefits of the approach to replace the traditional usage of 0D maps.