Development and Assessment of an Integrated 1D-3D CFD Codes Coupling Methodology for Diesel Engine Combustion Simulation and Optimization

Abstract

In this paper, an integrated and automated methodology for the coupling between 1D- and 3D-CFD simulation codes is presented, which has been developed to support the design and calibration of new diesel engines. The aim of the proposed methodology is to couple 1D engine models, which may be available in the early stage engine development phases, with 3D predictive combustion simulations, in order to obtain reliable estimates of engine performance and emissions for newly designed automotive diesel engines. The coupling procedure features simulations performed in 1D-CFD by means of GT-SUITE and in 3D-CFD by means of Converge, executed within a specifically designed calculation methodology. An assessment of the coupling procedure has been performed by comparing its results with experimental data acquired on an automotive diesel engine, considering different working points, including both part load and full load conditions. Different multiple injection schedules have been evaluated for part-load operation, including pre and post injections. The proposed methodology, featuring detailed 3D chemistry modeling, was proven to be capable assessing pollutant formation properly, specifically to estimate NOx concentrations. Soot formation trends were also well-matched for most of the explored working points. The proposed procedure can therefore be considered as a suitable methodology to support the design and calibration of new diesel engines, due to its ability to provide reliable engine performance and emissions estimations from the early stage of a new engine development.

Hydrogen—An Alternative Fuel for Automotive Diesel Engines Used in Transportation

“…To mitigate the related environmental impact, restrictions are imposed to diminish these harmful emissions (which, in terms of greenhouse gas emissions, are estimated to add up to 20% for transportation) [3]. Specifically, severe limitations are set for unburned hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO 2 ), nitrogen oxides (NO x ), particles, and smoke [1][2][3][4][5][6]. As the root of the generation of these pollutants is the automotive engine, it is remarked that HC and CO result as a consequence of incomplete combustion, while NO x (mainly nitrogen monoxide-NO and nitrogen dioxide-NO 2 , known as NO x emissions in the internal combustion engine (ICE) domain) is produced in the chemical reaction between nitrogen and oxygen unfolding in high-pressure conditions, such as the ones registered for in-cylinder combustion in engines [4].…”

“…It is highlighted that the particles emitted by diesel engines have dimensions within the range from 0.01 to 1 µm, so they can easily enter the human lungs, therefore representing a major health threat. Smoke is composed of a suspension of liquid particles of unburned or partially burned fuel with diameters of up to 1 µm (white or blue smoke), or of carbon particles with diameters greater than 1 µm (black smoke) [4]. White and blue smoke appear under starting, idling, or low-load conditions when the engine thermal regime is reduced.…”

“…For diesel engine operation, the largest share of the exhaust gases in terms of pollutant emissions belongs to nitrogen oxides, solid particles, and smoke [3][4][5][6][7]. As diesel engines are widespread in transportation, it is of crucial importance to significantly diminish the concentration of the pollutants and greenhouse gas emissions in the exhaust gas flows [8].…”

CFD Analysis of Sector Combustion Simulation in Four Stroke Direct Injection Diesel Engine

“…The production of high turbulence intensity is one of the most important factors for stabilizing the propagation of flame, especially in the case of lean-burn combustion (Kurniawan et al, 2007). The use of a bowl piston combustion chamber will result in substantial swirl amplification at the end of the compression stroke, which is important for the engine performance and emission characteristics (Erdil & Kodal, 2007).Computational Fluid Dynamics (CFD) simulations are of paramount importance to integrate experimental studies for an efficient optimization and design of new Diesel combustion systems (Millo et al, 2020). CFD allow designers to simulate and visualize the complex fluid dynamics with lower cost and lower analysis duration, providing that the simulation fulfil the optimized setup (Shafie et al, 2017).…”

A 1D–3D Approach for Fast Numerical Analysis of the Flow Characteristics of a Diesel Engine Exhaust Gas

“…Millo et al analyzed the gas flow in the cylinder of the diesel engine by combining the 1D commercial code GT-SUITE and the 3D commercial code CONVERGE CFD. To combine 1D and 3D, the function built into the commercial code is used, and a method for predicting the performance of a diesel engine is proposed using the results of gas flow analysis [16].…”