Development of a zero-dimensional turbulence model for a spark ignition engine

Abstract

The necessity for the use of one-dimensional simulation is growing because cost and time required for hardware optimization and optimal calibration of engines based on experiment are increasing dramatically as engines are equipped with growing numbers of technologies. For one-dimensional simulation results to be more reliable, the accuracy and applicability of the combustion model of a one-dimensional simulation tool must be guaranteed. Because the combustion process in a spark ignition engine is driven by the turbulence, many of existing models focus on the prediction of mean turbulence intensity. Although many successes in the previous models can be found, the previous models contain a large number of adjustable constants or require information supplemented from three-dimensional computational fluid dynamics simulation results. For improved applicability of a model, the number of adjustable constants and inputs to the model must be kept as small as possible. Thus, in this study, a new zero-dimensional (0D) turbulence model was proposed that requires information on the basic characteristics of the engine geometry and has only one adjustable constant. The model was developed based on the energy cascade model with additional consideration of following aspects: loss of kinetic energy during the intake stroke, the effect of piston motion during the compression and the expansion stroke, modifications to correlations for integral length scale, geometric length scale, and production rate of turbulent kinetic energy. An adjustable constant to consider engine design which determines tumble strength was also introduced. The comparison of the simulation results with those of three-dimensional computational fluid dynamics confirmed that the developed model can predict the mean turbulence intensity without case-dependent adjustment of the model constant.

Prediction Modeling and Analysis of Knocking Combustion using an Improved 0D RGF Model and Supervised Deep Learning

“…However, the multipliers obtained in this study are not universal, as they were only validated using the engine used in this study. In addition, there is an issue with the precision of the models [42]. Nonetheless, well-matched pressure profiles were achieved, so this point is beyond the scope of this study.…”

A New Physics-Based Modeling Approach for a 0D Turbulence Model to Reflect the Intake Port and Chamber Geometries and the Corresponding Flow Structures in High-Tumble Spark-Ignition Engines

“…The non-tumble mean kinetic energy (MKE) is treated as typical MKE in -model [15,23], except the fact that it is limited to the kinetic energy by the non-tumble velocity component ( = ∑ , , ). The TKE production rate from non-tumble MKE and the corresponding term in equation are:…”

“…Since the cause is interpreted to be the change of flow area, it may be correlated to the ratio of the valve curtain area to the cylinder bore area, as in [23]. This coefficient must be less than 1 because the velocity cannot be increased after expansion.…”

Performance Analysis of a Biodiesel-Fired Engine for Cogeneration

“…These works investigate the heat release calculation, the heat transfer modelling, the knock phenomenon in spark ignition engine [5][6][7][8][9] and the engine behaviour in multi-source energy systems [10]. Other researcher focused on turbulence modeling during the intake process [11][12][13][14][15], as well as the modeling of the emission control during the exhaust process [16][17]. The zero-dimensional models, based on the first law of thermodynamic, use semi-empirical relationships to describe each thermodynamic process occurring in the engine operating cycle.…”