The safe soot limit is crucial for the optimization and regeneration management of Diesel Particulate Filters (DPF). Coupled exhaust after-treatment and stress models can largely substitute the ‘inherently’ destructive and cost-intensive experiments with, however, increased time/computational needs. The target of this work is to demonstrate that the role of DPF geometrical and thermomechanical properties on soot mass limit can be analyzed systematically with efficient solvers and advanced meshing methodologies. Application examples for cases of uncontrolled DPF regeneration mode with and without accumulated ash are discussed. The soot limit is not directly correlated with peak temperature as often assumed.

View full abstract

Efforts to improve restraint design for occupant protection require a detailed knowledge of human kinematic response including that of the spine. This study presents the spinal displacement response of eight PMHS subjected to a simulated 40 km/h frontal collision. The eight PMHS that approximated 50th percentile stature and mass were restrained by a three-point belt. During the tests a motion capture system was used to obtain the 3D displacements of the head, T1, T8, L2, L4, and pelvis relative to the vehicle coordinate system. The results will be immediately useful for kinematic biofidelity assessments of both ATDs and computational models.

View full abstract

Crossing collisions caused by cognitive error often occur at unsignalized intersections. For the countermeasure, driver assistant systems that warn a driver against stop sign violation are researched and commercialized. However, if a driver is warned in spite of recognizing an intersection, he or she may feel annoyance and turn the system off. In this research, an index of intersection perception utilizing the saliency map was formulated in order to simulate the driver’s cognition. Then, an assistance method proposed gives a driver early alert only when an approaching intersection is difficult to notice. Applicability of this index was confirmed by a driving simulator, and effectiveness of the proposed assistance method was verified for subjects with the special eyeglasses emulating elderly person’s vision.

View full abstract

We investigated whether riding a motorcycle in daily life has beneficial effects on the cognitive functions of healthy subjects. Twenty-two healthy right-handed men, who had a significant break from riding, participated in this study. They were randomly assigned to either the intervention or control group. The intervention group was asked to ride a motorcycle in their daily life for two months. The intervention group showed improvement of their visuospatial cognition compared with the control group. Results of this study indicate that riding a motorcycle in daily life could have beneficial effects in returning riders.

View full abstract

The purpose of this study was to clarify the cortical activity of the dorsolateral prefrontal cortex (DLPFC) while motorcycles were being ridden. Sixteen healthy right-handed men who use motorcycles in their daily lives were recruited. Their brain activity was measured using a prototype of wearable optical topography while they were actually riding a motorcycle. We found that their brain activation patterns, which reflect the cognitive strategies behind their riding behaviors, differed depending on whether they were users of road bikes or scooters. Also, DLPFC activity, which reflects an increase in cognitive and motor demands, was greater in riders of on-road type motorcycles than scooters.

View full abstract

Present paper outlines the simulation technique for dynamic analysis of cavitating Diesel injector flow, considering longitudinal and lateral needle displacements. The current research is performed with the goal to eventually enable direct coupling of 1D hydraulic tools, providing exact needle positions in three coordinates, with 3D CFD tool AVL FIRER. At this stage the needle displacements in longitudinal and lateral directions have been predefined. In reality the needle will be pushed aside by the flow for different reasons; different radii at the hole inlet and non-equi-angular hole positioning. Predicted flow shows visible non-uniformity resulting from non-symmetric nature of the injector domain.

View full abstract