Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Battery (electricity). The organization has 40032 authors who have published 55003 publications receiving 735317 citations. The organization is also known as: Toyota Motor Corporation & Toyota Jidosha KK.

A Mixed-Time-Scale SGS Model With Fixed Model-Parameters for Practical LES

Abstract: A new subgrid-scale (SGS) model for practical large eddy simulation (LES) is proposed. The model is constructed with the concept of mixed (or hybrid) time scale, which makes it possible to use consistent model parameters and to dispense with the distance from the wall. The model performance is tested in plane channel flows, and the results show that this model is able to account for near-wall turbulence without an explicit damping function as in the dynamic Smagorinsky model. The model is also applied to the backward-facing step flow examined by Kasagi and Matsunaga (1995) experimentally. The calculated results show good agreement with experimental data, while the results obtained using the dynamic Smagorinsky model show less accuracy and less computational stability. To confirm the validity of the present model in practical applications, the three-dimensional complex flow around a bluff body ( Ahmed, 1984 ) is also calculated with the model. The agreement between the calculated results and the experimental data is quite satisfactory. These results suggest that the present model is a refined SGS model suited for practical LES to compute flows in a complicated geometry.

How General is the Conversion Reaction in Mg Battery Cathode: A Case Study of the Magnesiation of α-MnO2

Abstract: α-MnO2 was previously reported as a Mg battery cathode with high discharge capacity but poor cyclability. Surprisingly, the discharge product did not contain any structurally invariant α-MgxMnO2, implying that the magnesiation of α-MnO2 does not follow the typical intercalation route. In the current work, we perform a comprehensive analysis about the magnesiation behavior of α-MnO2 by comparing the reactions following the intercalation and conversion routes. Our results unambiguously demonstrate that the conversion reaction that generates amorphous magnesium and manganese oxide is thermodynamically more preferable than the intercalation reaction. Even if the metastable intercalation could occur due to a possible kinetic barrier that prevents direct conversion, we predict that Mg can only be intercalated to a concentration below α-Mg0.125MnO2. Beyond that composition, the structure of the intercalated compound undergoes a strong tetragonal to orthorhombic distortion, which may destruct the integrity of the...

Budding and fission dynamics of two-component vesicles

Abstract: We studied the shape deformation induced by the phase separation of two-component vesicles using a dissipative particle dynamics simulation. Two types of amphiphiles, which have the same architecture but segregate from each other, are modeled by connecting particles representing the hydrophilic head and hydrophobic tail groups. After vesicle formation using a single component system, some of the amphiphiles are replaced by a second component, and then phase separation on the vesicle is simulated. Under appropriate conditions, typical shape deformations of a vesicle, such as crenated and invaginated shapes, are observed. We demonstrate that the budding and the fission are facilitated by lateral phase separation upon vesicle coupling to an asymmetric transversal distribution of amphiphiles in the bilayer. Moreover, simulations show a possible new pathway for the fission process triggered by cleavage along the domain boundary. Mesoscopic simulation based on a simple coarse-graining model reveals the dynamics of amphiphiles in vesicles that is essentially unpredictable using a conventional continuum model or full atomistic simulation.

Achieving Lower Exhaust Emissions and Better Performance in an HSDI Diesel Engine with Multiple Injection

Abstract: The effects of multiple-injection on exhaust emissions and performance in a small HSDI (High Speed Direct Injection) Diesel engine were examined The causes for the improvement were investigated using both in-cylinder observation and three-dimensional numerical analysis methods It is possible to increase the maximum torque, which is limited by the exhaust smoke number, while decreasing the combustion noise under low speed and full load conditions by advancing the timing of the pilot injection Dividing this early-timed pilot injection into two with a small fuel amount is effective for further decreasing the noise while suppressing the increase in HC emission and fuel consumption This is realized by the reduced amount of adhered fuel to the cylinder wall At light loads, the amount of pilot injection fuel must be reduced, and the injection must be timed just prior to the main injection in order to suppress a possible increase in smoke and HC After-injection, which injects a small amount of fuel immediately after the end of the main injection, reduces smoke, HC and fuel consumption This is because the jet flame of the after-injection carries the remaining soot of the main injection to the squish area, and then oxidizes that together with the soot which previously existed in the squish area by promoted atmospheric temperature and enhanced mixing with fresh air

System for integrally controlling automatic transmission and engine

Abstract: A system for integrally controlling an automatic transmision and an engine, wherein gear stages are automatically switched in accordance with a preset shift map, and an engine torque is changed by a predetermined change value during shifting to thereby maintain the satisfactory shift characteristics, comprising: a device for determining whether or not an engine torque change can be actually carried out without a problem; and means for regulating said engine torque change when said engine torque change cannot be actually carried out, to thereby prevent the problem from occurring.