Exhaust gas aftertreatment systems in trucks and industrial machines are crucial for meeting increasingly stringent emission regulations for internal combustion engines. In a urea-SCR system, nitrogen oxides (NOx) from diesel engines are remediated using a urea water solution. Understanding gas-liquid two-phase flows is essential, however, accurate performance predictions through computational fluid dynamics (CFD) remain challenging. The new Euro7 regulation, low-temperature tests (-7˚C) as per UN-GTR15, adds complexity. This study addresses the need to analyze fluid behaviors at temperatures below 200˚C to improve predictions. We introduce a novel approach using visualization equipment to construct a urea-SCR simulator. Fluid behavior was observed, and the obtained velocity distributions were computed using particle image velocimetry (PIV) analysis. An analysis of the drag force on the gas flow to the droplet indicates, that velocity differences between the gas and the droplet primarily drive drag force variations. This highlights the importance of deriving experimental coefficients via visualization experiments and PIV analysis. Moreover, our findings indicate that the initial injected droplet velocity outside the gas flow increased with gas temperature. Using these validations, we examined initial conditions to analyze heating scenarios of combined PIV and the discrete droplet model (DDM), offering an alternative to CFD for predicting droplet behavior.

In this study, the strength improvement of adhesive joint is discussed for the steel/epoxy butt joints due to the duplicated interaction of additional notches. The experiment is conducted by varying the adhesive layer thickness h and the notch depth t in the range h =0.1~2.0mm and t =0.4~1.7mm when the specimen diameter D =12.7mm and the interval between the notch and the interface c =1.0mm. The intensity of the singular stress field (ISSF) at the interface end is analyzed by the proportional method, as well as the interface stress distribution. The results show that the adhesive strength can be expressed as a constant ISSF independent of h and t except for too deep notch. The adhesive strength σ_c^JIS (h) of the butt joint measured by following JIS (Japan Industrial Standard) without notch increases with decreasing h due to the interaction of upper and lower adhesive bondlines. The adhesive strength for the case of additional notches increases with increasing t due to the duplicated interaction. The analytical and experimental results showed that the adhesive strength can be improved due to the duplicated interaction of suitable additional notch.

In order to prevent traffic accidents, automobiles equipped with driving support devices are becoming widespread. The amount of information related to safe driving provided by the manual is increasing, and the driver cannot properly process information, causing an accident. By providing appropriate information to various drivers, it may be possible to give the drivers a correct understanding and guide them to the proper handling of the driving support device. We will develop an active manual that dynamically changes according to the driver, instead of providing uniform information using a paper manual. To develop an active manual, it is necessary to detect the driver's ITS proficiency and to generate and provide appropriate quantity and quality information to the driver. In this paper, as the first step, we propose a method to detect and classify the driver's ITS proficiency. First, we show that there is no difference in understanding between beginners at ITS and experts at ITS due to the politeness of explanations and instructions, and that experts at ITS tend to misunderstand information due to stereotypes. Next, we define a new index called proficiency comprehension and propose a method to classify various drivers into proficiency comprehension "high", "medium", and "low".

This study produced experimental cylinders cooled by fins with slits only in front of the air flow, and examined the effect of number of slits in the front on cylinder cooling. We tested these experimental cylinders in a wind tunnel at air velocities of 20 km/h (5.6 m/s), 40 km/h (11.1 m/s) and 60 km/h (16.7 m/s). We measured the temperature inside the cylinder, to determine the heat transfer rate from the cylinder. We also visualized the air flow between the fins using the smoke wire method, and the flow over the fin surface using the oil film method, to understand the air flow around the cylinder. Results indicated that, as the number of the slits, all arranged 30° apart around the edge of the fin, and set in line, increased to 5 in the front, cylinder cooling increased. Then cylinder cooling did not increase as the number of the aligned slits exceeded 5. By staggering the fins with 6 slits and 7 slits in the front, cylinder cooling improved more than the 5 aligned slits.

It is generally known that springback occurs in the bending process of rebars. Prediction of springback is important to improve the quality of bent rebars. Studies have been conducted on the prediction of springback using CAE. It has been reported that variations in the material properties required for analysis can lead to variations in the predicted results and that material modeling and calculations can be very time-consuming. There is a generally known equation for angle change with springback. This equation is for bending with a uniform radius of curvature. Bent rebars do not have a uniform radius of curvature due to the processing method. The purpose of this research is to establish a springback prediction method by in- process measurement of bending machines. In this report, as a first step, the angle change with springback when round steel bar is bent by in the targeted processing method was considered based on the equation about springback. By examining the shapes for each region of bent steel bar, it is possible to calculate the angle change with springback based on the equation about springback. The angle change with springback at the target rotation angle for rebar can be predicted by bending with unloading before reaching the maximum bending angle using a bending machine.