Fluid Dynamic Modeling of the Gas Flow with Chemical Specie Transport through the Exhaust Manifold of a Four Cylinder SI Engine 1999-01-0557
The paper describes the 1-D fluid dynamic modeling of unsteady flows with chemical specie tracking in the ducts of a four-cylinder s.i. automotive engine, to predict the composition of the exhaust gas reaching the catalyst inlet. A comprehensive simulation model, based on classical and innovative numerical techniques for the solution of the governing equations, has been developed. The non-traditional shock-capturing CE-SE (Conservation Element-Solution Element) method has been extended to deal with the propagation of chemical species. A comparison of the MacCormack method plus FCT or TVD algorithms with the CE-SE method has pointed out the superiority of the latter scheme in the propagation of contact discontinuities. A realistic composition of the exhaust products in the cylinder, evaluated by a two-zone combustion model including emission sub-models, has been imposed at the opening of the exhaust valve, considering the effect of short-circuit of air during valve overlap. The fluid dynamic code has been applied to investigate the transport of the resulting chemical species along the exhaust manifold, towards the catalyst. A detailed 1-D model of the catalytic converter has been adopted, considering the distributed and concentrated pressure losses in the system.
Citation: Onorati, A., Ferrari, G., and D'Errico, G., "Fluid Dynamic Modeling of the Gas Flow with Chemical Specie Transport through the Exhaust Manifold of a Four Cylinder SI Engine," SAE Technical Paper 1999-01-0557, 1999, https://doi.org/10.4271/1999-01-0557. Download Citation
A. Onorati, G. Ferrari, G. D'Errico
Department of Energetics, Politecnico di Milano
International Congress & Exposition
Electronic Engine Control Technologies-PT-73, SI Engine Modeling-SP-1451, SAE 1999 Transactions - Journal of Engines-V108-3