Real-Time Simulation of CNG Engine and After-Treatment System Cold Start Part 1: Transient Engine-Out Emission Prediction Using a Stochastic Reactor Model

• DOI: 10.4271/2023-01-0183
• Publication Date: 2023-04-08T15:52:53Z
• Authors: Reddy Babu Siddar...; Tim Franken; Michal Pasternak; Larisa Leon de Sy...; Johannes Oder; Hermann Rottengruber; Fabian Mauss
• Keywords: Cold start (automotive); Large-Eddy Simulation

<div class="section abstract"><div class="htmlview paragraph">During cold start of natural gas engines, increased methane and formaldehyde emissions can be released due to flame quenching on cylinder walls, misfiring the catalyst not being fully active at low temperatures. Euro 6 legislation does regulate emissions. New limits for these two pollutants have been proposed by CLOVE consortium 7 scenarios. These proposals indicate tougher requirements aftertreatment systems engines.</div><div paragraph">In present study, a zero-dimensional model real-time engine-out emission prediction transient engine is presented. The incorporates stochastic reactor spark ignition engines tabulated chemistry. chemistry approach allows account physical chemical properties fuels in detail using a-priori generated laminar speed combustion look-up tables. turbulence-chemistry interaction within chamber predicted K-k turbulence model. optimum parameters are trained matching experimental pressure nine steady-state operating points.</div><div paragraph">Subsequently, applied predicting WLTP passenger car start. comprise nitrogen oxide, carbon monoxide, dioxide, unburnt methane, formaldehyde, hydrogen. simulation results validated comparing measurements different ambient temperatures (-7°C, 0°C, 8°C 20°C). Additionally, sensitivity towards air-fuel-ratio (λ=1.0 λ=1.3) quality (H-Gas L-Gas) investigated.</div></div>