A detailed Mean Value Model of the exhaust system of an automotive Diesel engine

Analysis of the Effects of Catalytic Converter on Automotive Engines Performance Through Real-Time Simulation Models

“…It should be noted that working fluid has been considered as a mixture of 7 chemical species, i.e., N 2 , O 2 , CO 2 , H 2 O, CO, H 2 NO. The vector of pollutant concentrations {X mi } in the exhaust gases (i.e., engine out gases) can be obtained from experimental data in form of look-up tables as functions of engine operating parameters (e.g., equivalence ratio ϕ, engine speed n and power output; Fiorani et al, 2008). In the same way the vector {η i } of conversion efficiencies can be defined through look-up tables defined experimentally as a function of monolith temperature T mon and gas velocity (Fiorani et al, 2008).…”

“…The vector of pollutant concentrations {X mi } in the exhaust gases (i.e., engine out gases) can be obtained from experimental data in form of look-up tables as functions of engine operating parameters (e.g., equivalence ratio ϕ, engine speed n and power output; Fiorani et al, 2008). In the same way the vector {η i } of conversion efficiencies can be defined through look-up tables defined experimentally as a function of monolith temperature T mon and gas velocity (Fiorani et al, 2008). This approach (which is mainly black-box, as usually required by Real-time models) allows considering further reactions that may occur in the catalyst by introducing proper empirical correlations for the simulation of different catalytic converters and aftertreatment systems.…”

“…Compressor and turbine models were identified on the basis of their characteristics from the manufacturer (Gambarotta and Lucchetti, 2013). Maps for the estimation of pollutants concentrations in exhaust gases are derived from Fiorani et al (2008). The algorithm developed for the integration of model equations uses a constant principal time step of 2 ms and a variable time step for in-cylinder processes to keep an angular step of ∼1 • CA independently of engine speed n. In this application, on a 2 GHz PC with 2 Gb RAM, the ratio of simulation time to physical time was always remarkably lower than 0.65.…”