Cycle-to-Cycle Variation Analysis of Gasoline Engine by LES (First Report)

Takayuki Ito･Masahiro Matsuoka (JARI)･Ryo Adachi (SUBARU)･Toru Takabayashi (Honda Motor)

The suppression of cycle-to-cycle variation is an important issue in improving the efficiency of gasoline engines. In this paper, multi-cycle simulation using LES are performed for a direct-injection gasoline engine, and the cycle-to-cycle variation of fuel concentration near the spark plug is compared between simulated and measured. This report focuses on the effects of grid resolution on simulation accuracy under different air-fuel ratio conditions.

Cycle-to-Cycle Variation Analysis of Gasoline Engine by LES (Second Report)

Masahiro Matsuoka･Takayuki Ito (JARI)･Ryo Adachi (SUBARU)･Toru Takabayashi (Honda Motor)

Large Eddy Simulation (LES) was performed on a gasoline engine under different fuel injection systems and operating loads. Comparisons were made with measured values of fuel concentration near the spark plug and in-cylinder pressure during combustion, and it was confirmed that the LES could generally reproduce the trend of cycle-to-cycle variations under different conditions. The effect of grid resolution on the prediction accuracy of cycle-to-cycle variations under each condition was also discussed.

Construction of Online Co-simulation Environment (4)
-Study of Model Granularity Migration Process for Thermal Management Control Optimization-

Kenichiro Ogata･Keijiro Koide･Shunichi Kubota･Naoaki Takeda･Yusuke Suzuki･Go Toshizane･Seiya Nakasako (Honda Motor)･Ryohei Sugamata･Mitsunobu Saito (Honda R&D)

In powertrain development, in addition to performance design that maximizes the reduction of CO2 emissions, efficient development process with no rework and MBD are also necessary. Furthermore, fuel economy performance that assumes actual usage environment is required, EPA 5 cycle which evaluates various environments as fuel economy performance evaluation has been applied. In the EPA 5 cycle performance prediction considering engine temperature is essential, and it is necessary to assume MBD from performance design stage to performance verification stage. This study summarizes transition from conceptual model described in previous report to detailed model and its utilization in vehicle development process.

Construction of Online Co-simulation Environment (5)
-Improvement of Thermal Plant Model for Enhancing Prediction Accuracy of Engine Coolant Temperature-

Seiya Nakasako･Keijiro Koide･Kenichiro Ogata (Honda Motor)

In a Co-Simulation environment, the accurate prediction of engine coolant temperature is crucial. However, the fluid behavior around the radiator in radiator fan operating conditions is complex, posing challenges for representation using a 1D model. This paper proposes a model enhancement method that considers airflow through the clearance between the radiator and surrounding components.

Improvement of Transient Air Volume Estimation Model for High-volume EGR Models

Toshiyuki Nakamura･Akihiro Katsuura･Yujiro Tsutsumi (Honda Motor)

This document describes the improvement of the transient air volume estimation model for models with large-capacity EGR. Based on the transient analysis of EGR gas and fresh gas using 1DSim, an air volume estimation model was constructed that takes into account the delay of the pipe volume after the EGR valve and the inter-cylinder deviation effect. By applying this model, the accuracy of air volume estimation during transients was improved and product quality was improved.