An autoignition combustion model for homogeneous charge compression ignition engine cycle simulations

Abstract

This paper presents an autoignition combustion model, which can be used in conjunction with a one-dimensional gas dynamics and zero-dimensional thermodynamics engine simulation code for homogeneous charge compression ignition (HCCI) engine cycle simulations. The model consists of two parts: the first predicts autoignition timing, based on the integral of the knock delay time, and the second predicts the heat release rate, based on the Watson correlation for diesel engines. The equations for the model were fitted with empirical coefficients derived from experimental results. The experimental data were measured under a number of engine operating conditions for different loads, speeds, and equivalence ratios. The experiments were performed on a Jaguar V6 HCCI engine employing internal exhaust gas residual trapping through cam profile switching and variable valve timing control. It was found that the location of 50 per cent mass fraction burned (MFB) and the peak rate of pressure rise can be chosen as the key parameters charactering the HCCI combustion in engine simulations. The fitted combustion model was then implemented into the V6 engine Ricardo WAVE TM model and validation of its predictive calculations was obtained using a different set of experimental data. The results show that the predicted 50 per cent MFB position is within an average error of 1.84u crank angle (CA) and the predicted peak rate of pressure rise is within an average error of 0.53 bar/deg CA (7.2 per cent).

The effects of key parameters on the transition from SI combustion to HCCI combustion in a two-stroke free piston linear engine

“…In the study, an HCCI auto-ignition delay model is described by the Arrhenius equation [14,[35][36][37][38][39]:…”

Real-time control oriented HCCI engine cycle-to-cycle dynamic modelling

“…The differences between the experimental results and the simulation results (see Figs. [8][9][10][11][12][13] are because of the simplified one-zone HCCI combustion model. Also, the model assumes no gas leakage and no heat transfer between the in-cylinder mixture and the cylinder walls.…”

“…Currently, there are two popular approaches for modelling this part. The skeleton kinetic mechanism (SKM) method [12] and the heat release correlation method [10,13] . SKM is normally used for low molecular weight fuels or single component fuels, such as propane (C3H8) or ethanol (C2H5OH) [9,11] .…”

“…As a result, the second approach, the heat release correlation method, was developed. It is an approach that is based on experimental data and empirical formulas rather than the complex chemical reaction mechanisms [10,13] . The model introduced in this paper adopts this method.…”

Thermodynamic model for homogeneous charge compression ignition combustion with recompression valve events and direct injection: Part II—Combustion model and evaluation against transient experiments

“…Modified versions of the AI have been frequently utilized for HCCI modeling. 16,[18][19][20][21] A key component of these models is an Arrhenius ignition delay expression, which often relies on thermodynamic information from the domain, such as temperature, pressure, and composition (e.g. fuel-air equivalence ratio and oxygen concentration).…”