This course, based on the ASME Y14.5-2009 standard, provides an in-depth explanation of how to use tolerance stacks to analyze product designs and how to use geometric tolerances in stacks. You will learn the essential methods and concepts used for creating 1D part and assembly tolerance stacks.
Individuals responsible for quality management system, implementation, and auditing to the AS9100:2016 series of standards for Aviation, Space, and Defense will require an understanding of the requirements for the preparation and execution of the audit process as defined in these revised standards. Management and implementers of AS9100:2016 Rev. D within these organizations must also be aware of what these requirements mean for their company.
The avionics hardware industry world-wide is now commonly required to follow DO-254 Design Assurance Guidance for Airborne Electronic Hardware for literally all phases of development: Safety, Requirements, Design, Logic Implementation, V&V, Quality Assurance, etc. The DO-254 standard is a companion to the software DO-178B standard; however, there are many differences between hardware and software which must be understood. This basic course introduces the intent of the DO-254 standard for commercial avionics hardware development.
The efficiency and emission potential of pre-chamber combustion in a Miller cycle light duty gasoline engine operated under part load was evaluated. Several pre-chamber designs that examine the engine performance tradeoffs with nozzle diameter, pre-chamber volume, number of nozzles, and pre-chamber fuel stratification were investigated for both excess air and cooled external EGR dilution strategies. The introduction of pre-chamber jet ignition was observed to significantly reduce the main-chamber combustion duration while reducing cyclic variability, benefiting from the long-reach ignition jets and enhanced turbulence. However, the pre-chamber design that provided the fastest combustion led to reduced brake efficiency primarily due to increased heat loss. Maintaining the total nozzle area while increasing the number of nozzles was identified to minimize the additional heat loss while maintaining fast burn rates.
To understand the fundamental mechanisms of the main chamber charge ignition in pre-chamber combustion (PCC) engines, the effects of the composition enrichment and stratification in the pre-chamber were investigated numerically using CONVERGE. A well-stirred reactor combustion model coupled with a methane oxidation mechanism reduced from GRI 3.0 was used. A closed-cycle simulation is considered and the entire domain (pre-chamber and main chamber) was initialized with λ = 1.3 at inlet valve closing time. The initial flow field was imposed by mapping the field variables obtained from a full cycle simulation, thus approximating real engine conditions. An additional amount of fuel is further injected into the pre-chamber to achieve a global λ of 0.7 and 1.0 inside the pre-chamber region at spark timing. Varying the pre-chamber λ value allows to produce jets with various compositions and topologies.
Rapid Compression Machines (RCM) offer the ability to easily change the compression ratio and the pressure/mixture composition/temperature to gather ignition delay data at various engine relevant conditions. Therefore, RCMs with optical access to the combustion chamber can provide an effective way to analyze macroscopic spray characteristics needed to understand the spray injection process and for spray model development, validation and calibration at conditions that are suitable for engines. Fuel surrogates can help control fuel parameters, develop models for spray and combustion, and perform laser diagnostics with known fluorescence characteristics. This study quantifies and evaluates the macroscopic spray characteristics of multi-component gasoline surrogates in comparison to their gasoline counterparts, under gasoline direct injection (GDI) engine conditions.
A new method is demonstrated for rating the “severity” of a hypoid gear set duty-cycle (revolutions at torque) using the intercept of T-N curve to support gearset selection and sizing decision across vehicle programs. Historically, it has been customary to compute a cumulative damage (using Miner's Rule) for a rotating component duty-cycle given a TN curve slope and intercept for the component and failure mode of interest. The slope and intercept of a T-N curve is often proprietary to the axle manufacturer and are not published. Therefore, for upfront sizing and selection purposes representative T-N properties are used to assess relative component duty cycle severity via cumulative damage (non-dimensional quantity). A similar duty-cycle “severity” rating can also be achieved by computing the intercept of the T-N curve instead of cumulative damage, which is the focus of this method.
A ball joint is an important part of the automobile drive shaft system, as well the contact stress inside the ball joint is an important goal in the process of designing a ball joint. At present, the analysis of the contact stress inside the ball joint is focused on the static contact stress analysis. The static contact stress analysis, however, cannot reflect the change of the contact stress inside the ball joint. In order to analyze the contact stress of the ball joint more effectively, a multi-body dynamic model of the ball joint is proposed to study the dynamic contact stress inside the ball joint. In the multi-body dynamic model, the balls, the cage, the inner race and the outer race are regarded as the flexible body, as well the contact parameters of each contact pair are determined on the basis of Hertz contact theory.
Recently, electric-powered vehicle such as HV, PHV, EV and FCV is highly demanded and getting attention, due to increasing of environmental-consciousness. Also, environmental regulation is getting more and more strict in many countries and regions. Then, environmental friendly vehicle is needed to be spread more and more than ever. As you can find in “TOYOTA Environmental challenge 2050”, TOYOTA will rapidly increase the number of new car sales of electric-powered vehicle towards 2050.We developed transaxle for FCV (rear mounted) and for EV (front mounted) at the same time, and realized coexistence of vehicle mountability and many common parts. The new EV and FCV transaxle is developed with utilizing HV technology as much as possible. And concepts of the transaxle are Compact, Low mechanical loss, High performance and Quietness. These features are well-balanced in high level, and the transaxle contributes competitive power performance and cruising range as vehicle.