Self-Ignition Delay Prediction in PCCI Direct Injection Diesel Engines Using Multi-Zone Spray Combustion Model and Detailed Chemistry

Abstract

A multi-zone direct-injection (DI) diesel combustion model has been implemented for full cycle simulation of a turbocharged diesel engine. The above combustion model takes into account the following features of the spray dynamics: • the detailed evolution process of fuel sprays; • interaction of sprays with the in-cylinder swirl and the walls of the combustion chamber; The above sub-models were integrated into DIESEL-RK software, which is a full-cycle engine simulation tool, allowing more advanced analysis of PCCI and HCCI diesels.

Simulation of Dual-Fuel Diesel Combustion With Multi-Zone Fuel Spray Combustion Model

“…The theoretical basis of this project is the multi-zone diesel spray combustion model described in [5,6]. This model was successfully applied previously, demonstrating very good correlation between obtained theoretical and experimental results for engines with a single-and multi-stage fuel injection [7][8][9][10] and for application of biofuel [11,12]. The theoretical background of splitting fuel sprays into 10 characteristic zones (see Fig.…”

“…Therefore in the current stage of the research the following approach was deployed for determination of the start of ignition: if there is only methanol in the cylinder then Eq. (16) is used for the ignition delay prediction; if there is a mixture of methanol and diesel oil in the engine then the conventional equation for the diesel oil ignition delay period is used as described in [5][6][7][8][9][10][11][12]. In the latter case it is assumed that combustion of methanol starts with the ignition of diesel oil.…”

“…The theoretical background of splitting fuel sprays into 10 characteristic zones (see Fig. 1), calculation of evolution of the length and shape of the fuel sprays, their interaction with the air flow, walls and each other and also calculations of their evaporation and combustion are described in detail in [5][6][7][8][9][10][11][12]. The small number of zones in the calculation scheme allows radically decrease computing time in comparison with CFD.…”

“…Modelling of dual-fuel engines is carried out with the assumption that those equations can also accurately describe the process of the spray evolution and combustion of alternative fuels if their properties are used for determination of the numerical values of the above dimensionless parameters. In this work the models previously used by authors in [5][6][7][8][9][10][11][12] were further developed to compute combustion when some of phases/stages of the fuel injection process are used to deliver alternative fuel, namely methanol, by means of the second independent fuel supply system. Since methanol has the greater enthalpy of evaporation and higher self-ignition temperature in comparison with diesel oil the following refinements were made in the basic mathematical model:…”

Diesel/CNG Mixture Autoignition Control Using Fuel Composition and Injection Gap

“…Controlled auto-ignition based combustion systems, such as homogeneous charge compression ignition (HCCI) [1,2], stratified charge combustion ignition (SCCI) [3], premixed charge compression ignition (PCCI) [4], and reactive charge compression ignition (RCCI) [5] are the recent engine developments promising high efficiency, low emissions, and low fuel consumption.…”