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Cycle-To-Cycle Variability (CCV) must be properly considered when modeling the ignition process in SI engines operating with ultra-lean mixtures. In this work, a strategy to model the impact of the ignition type on the CCV was developed using the RANS approach for turbulence modelling, performing multi-cycle simulations for the power-cycle only. The spark-discharge was modelled through a set of Lagrangian particles, introduced along the sparkgap and interacting with the surrounding Eulerian gas flow. Then, at each discharge event, the velocity of each particle was modified with a zero-divergence perturbation of the velocity field with respect to average conditions. Finally, the particles velocity was evolved according to the Simplified Langevin Model (SLM), which keeps memory of the initial perturbation and applies a Wiener process to simulate the stochastic interaction of each channel particle with the surrounding gas flow.

The JASO GLV-1 standard was introduced in Japan for 0W-8 ultra-low viscosity gasoline engine oil to improve fuel economy. Fuel economy targets are specified for new oil but not for aged oil. In contrast, Sequence VI in the ILSAC GF-6 standard requires fuel economy improvement for both new and aged oils. This test simulates fuel economy improvement after 6400 km (FEI 1) and 16000 km (FEI 2) of driving based on US fuel economy certification testing. Currently, 0W-8 is not included in the ILSAC standard and the fuel-saving durability of 0W-8 has not been investigated. To include ultra-low viscosity oil like 0W-8 in future engine oil standards, it is necessary to know its fuel-saving durability and to examine the evaluation test method. This study focused on the fuel-saving durability of 0W-8 with or without the Mo friction modifier and considered the evaluation method.

During the acceleration of a vehicle, the contribution of the exhaust noise to the interior sound pressure level is significant. The acoustic insulation brought by the trim components must be designed with that consideration in mind. As such, there is an increasing need for developing reliable methods for predicting the airborne noise transmission between the exhaust system and the sound pressure level at the passenger's ears, taking into account the positive impact of various trim components. This paper presents a methodology that has been developed for addressing this need. Based on a finite/infinite element method, the computational procedure is divided in two steps: 1 The first step involves the exterior acoustic field all around the vehicle.

This paper describes a shaking vibration suppression approach for electric vehicles to support their quick and smooth acceleration response. Applied to the Nissan LEAF that has been specifically designed as a mass-market EV, the shaking vibration control system achieves a balance between highly responsive acceleration obtained with the electric drive motor, producing maximum torque of 280 Nm and maximum power of 80 kW, and a comfortable ride. A vehicle powered by an electric motor can provide quick acceleration response, thanks to the motor's fast torque response. However, the fast rate of increase in motor torque causes an uncomfortable shaking vibration that originates in the torsional torque of the drive shaft. The unique shaking vibration control system has been developed to achieve a balance between vehicle acceleration performance and ride comfort. Driving test results have confirmed that highly responsive acceleration is obtained without any shaking vibration.

In recent years, the study of volumetric ignition using high-speed (nanosecond) pulsed low temperature plasma for gasoline engines was reported by authors [ 1 ]. However, the fundamental analysis of ignition characteristics of the low temperature plasma ignition and the analysis of combustion initiation mechanism of the low temperature plasma ignition was not enough in the previous paper. In this study, a low temperature plasma igniter of a barrier discharge (silent discharge) model was developed for trial purpose. A fundamental analysis of ignition characteristics was carried out when the low temperature plasma ignition was applied as the ignition system for gasoline engine using single-cylinder. The difference between the ignition characteristics of the low temperature plasma and the thermal plasma of a conventional spark plug was investigated by comparing a combustion characteristic of both in various driving conditions.

Simultaneous crank-angle-resolved measurements of gasoline concentration and gas temperature were made with two-color mid-infrared (mid-IR) laser absorption in a production spark-ignition engine (Nissan MR20DE, 2.0L, 4 cyl, MPI with premium gasoline). The mid-IR light was coupled into and out of the cylinder using fiber optics incorporated into a modified spark plug. The absorption line-of-sight was a 5.3 mm optical path located closely adjacent to the ignition spark providing spatially resolved absorption. Two sensor wavelengths were selected in the strong bands associated with the carbon-hydrogen (C-H) stretching vibration near 3.4 μm, which have an absorption ratio that is strongly temperature dependent. Fuel concentration and temperature were determined simultaneously from the absorption at these two wavelengths.