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The adoption of the electronic controlled steering systems with new technologies has been extended in recent years. They have interactions with other complex vehicle subsystems and it is a hard task for the vehicle developer to find the best solution from huge number of the combination of parameter settings with track tests. In order to improve the efficiency of the steering system development, the authors had developed a steering bench test method for steering system using a Hardware-In-the-Loop Simulation (HILS). In the steering HILS system, vehicle dynamics simulation and the tie rod axial force calculation are required at the same time in the real-time simulation environment. The accuracy of the tie rod axial force calculation is one of the key factors to reproduce the vehicle driving condition. But the calculation cannot be realized by a commercial software for the vehicle dynamics simulation.

The 4th Workshop of the Engine Combustion Network (ECN) was held September 5-6, 2015 in Kyoto, Japan. This manuscript presents a summary of the progress in experiments and modeling among ECN contributors leading to a better understanding of soot formation under the ECN “Spray A” configuration and some parametric variants. Relevant published and unpublished work from prior ECN workshops is reviewed. Experiments measuring soot particle size and morphology, soot volume fraction (fv), and transient soot mass have been conducted at various international institutions providing target data for improvements to computational models. Multiple modeling contributions using both the Reynolds Averaged Navier-Stokes (RANS) Equations approach and the Large-Eddy Simulation (LES) approach have been submitted. Among these, various chemical mechanisms, soot models, and turbulence-chemistry interaction (TCI) methodologies have been considered.

The enhancement of vortex development, fuel-air mixing and heat release in diesel spray flame by inversed-delta injection rate shaping, having been predicted via LES simulation with detailed chemical kinetics, is experimentally confirmed for the first time. Newly developed 3-injector TAIZAC (TAndem Injector Zapping ACtivation) injector realizing aggressive inversed-delta injection rate shaping was used for single-shot combustion experiments in a constant volume combustion vessel. Simultaneous high-speed (120,000fps) and high-resolution (1,280 x 704 pixels) laser schlieren and UV OH* chemiluminescence imaging combined with subsequent Flame Imaging Velocimetry (FIV) analysis was employed to elucidate the correlation between vortex development and enhanced heat release.

This paper details an analysis theory to simulate various dynamic characteristics of a windshield wiper system on a vehicle for the purposes of computer-aided virtual prototyping. The analytical model consists of three-dimensional (3D) mechanical models of the complete wiper system and arm & blade subsystem which carries out complex reversal behavior. The equations of motion are solved considering the vehicle's 3D windshield surface data. Thus, the dynamic reaction forces in the vertical and frictional directions can be calculated at any point within the wiping pattern.

For better understanding of soot formation and oxidation processes in diesel spray flame, the nanostructure of primary soot particles directly sampled in a diesel spray flame was investigated via High-Resolution Transmission Electron Microscopy (HRTEM). A single-shot diesel spray flame was achieved in a constant volume combustion vessel under diesel-like conditions (Ta=1000K, Pa=2.7 MPa) and a micro-grid for HRTEM observation was directly exposed to the spray flame to thermophoretically sample soot particles onto the grid surface. A preliminary nanostructure investigation was conducted for x500k magnification HRTEM images of soot particles directly sampled in diesel spray flames of Fischer-Tropsch Diesel (FTD) fuel seeded with naphthalene as a representative aromatic substance. A MATLAB code for HRTEM image processing and analysis of lattice fringes within primary soot particles was developed and used to characterize the length, tortuosity and separation of lattice fringes.

The blade impact force at the top and bottom reversal points contributes significantly to wiper system noise. This paper describes a newly developed process to simulate blade reversal behavior. The results of this simulation can provide necessary insight into reducing blade reversal noise. As a result of simulation under various conditions, it is shown that the reversal impact force can be reduced by modifying the maximum rubber neck rotational angle and the rubber neck rotational spring constant. It is also shown that the reaction force at the top and bottom reversal points can be adjusted by modifying the arm head twist angle.

A mixed timescale subgrid model of a large eddy simulation was used to simulate the turbulence regime in diesel engine combustion. The combustion model used the direct integration approach with a diesel oil surrogate mechanism (developed at Chalmers University of Technology and consisting of 70 species and 309 reactions). Additional reactions for the generation and consumption of OH*, CO2*, and CH* species were added from recent kinetic studies. Collisional quenching and spontaneous emission resulted in de-excitation of the excited state radical. A phenomenological soot formation model (developed at Waseda University) was combined with the LES code. The following important steps were considered in the soot model: particle inception where naphthalene grows irreversibly to form soot, surface growth with the addition of C2H2, surface oxidation (induced by OH radicals and O2 attack), and particle coagulation.

This work proposes a focus on the simulation of a rotative volumetric expander via a CFD code. A customized application of OpenFOAM® has been developed to handle the particular motion of the calculation grid. The model uses a mesh to mesh interpolation technique, switching from a calculation grid to the new one on the basis of mesh quality considerations performed on the fly. This particular approach allows to account for the presence of leakages occurring between the stator and blade tips and also occurring at the top and bottom of the vanes. The fluid considered is the refrigerant R245fa, whose particular properties have been determined resorting to the NIST database. Experimental data, measured at different conditions of mass flow and fluid temperature, are compared to calculation results. Moreover, the CFD analysis has allowed the estimation of the influence of the leakage mass flow occurring at the tip of the vanes on the overall machine performances.