On-board diagnosis of engine and transmission systems has been mandated by government regulation for light and medium vehicles since the 1996 model year. The regulations specify many of the detailed features that on-board diagnostics must exhibit. In addition, the penalties for not meeting the requirements or providing in-field remedies can be very expensive. This course is designed to provide a fundamental understanding of how and why OBD systems function and the technical features that a diagnostic should have in order to ensure compliant and successful implementation.
Abstract Unlike conventional launch vehicles the winged body reusable launch vehicle needs to be tested and evaluated for its functionality during the pre-flight preparation at the runway. The ground based checkout systems for the avionics and actuators performance testing during pre-flight evaluation and actuation are not designed for rapid movement. The new kind of launch vehicle with conventional rocket motor first-stage and winged body upper-stage demands the system testing at Launchpad and at runway. In the developmental flights of the winged body part of the vehicle, the pre-flight testing needs to be carried out extensively at runway. The safety protocol forbids the permanent structure for hosting the checkout system near runway. The alternative is the development of a rapidly deployable and removable checkout system. A design methodology adopting conventional industrial instrumentation systems and maintaining mobility is presented.
This course is designed to provide an overview of the fundamental design objectives and the features needed to achieve those objectives for generic on-board diagnostics. The basic structure of an on-board diagnostic will be described along with the system definitions needed for successful implementation.
To satisfy recent stringent exhaust gas regulations, large amounts of Rh and Pd have been often employed in three-way catalysts (TWCs) as main active components. However, application of Pt-based TWCs are limited due to their lower thermal stability than Pd. Previously, we found that Pt-based TWCs with a small amount of CeO2 showed high catalytic performance in gasoline vehicles test. Especially, calcined CeO2 at high temperature before Pt loading (cal-CeO2) showed higher catalytic activity than untreated CeO2 after endurance at 1000 degree centigrade. This result could be attributed to higher redox performance and Pt dispersion derived from strong interaction between Ce and Pt. Even though cal-CeO2 has low specific surface area (SSA) given by preliminary calcination, it shows strong effects on catalytic performance. In other word, improvement of its SSA could be the most powerful way to prepare highly active Pt catalysts.
The gasoline particulate filter (GPF) represents a practical solution for particulate emissions control in light-duty gasoline-fueled vehicles. It is also seen as an essential technology in North America to meet the upcoming US EPA tailpipe emission regulation, as proposed in the “Multi-pollutant Rule for Model Year 2027”. The goal of this study was to introduce advanced, uncoated GPF products and measure their particulate mass (PM) reduction performance within the existing US EPA FTP vehicle testing procedures, as detailed in Code of Federal Regulations (CFR) part 1066. Various state-of-the-art GPF products were characterized for their microstructure properties and lab-bench performance for pressure drop and filtration efficiency, were then subjected to an EPA-recommended 2000mile on-road break-in, and finally were tested on an AWD vehicle chassis-dyno emissions test cell at both 25C and -7C ambient conditions.
The impending emission regulations in both China (CN7) and the United States (Tier 4) are set to impose more stringent emission limits on hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM). CN7 places particular emphasis on reducing particulate number (PN) thresholds, while the forthcoming United States Tier 4 legislation is primarily concerned with reducing the allowable particulate matter (PM) to an assumed limit of 0.5 mg/mile. Given the more stringent constraints on both PN and PM emissions, the development of enhanced aftertreatment solutions becomes imperative to comply with these new regulatory demands. Coated Gasoline Particulate Filters (cGPF) play a pivotal role as essential components for effective PN and PM abatement.
Recently, fuel cell stacks have been applied to various fields, and the importance of thermal energy management is increasing along with the increase in required power and heat dissipation. In particular, research and development is underway to improve various performance due to FCEV characteristics with a lower cooling temperature than ICE. Therefore, it is essential to develop a new cooling system to overcome these limitations. This study is a prior study to develop the evaporative cooling system by using water as a by-product of the stacks, and aims to identify the effects of variables affecting the performance. The commercial codes were used to simulate the quantitative sprayed area for actual evaluations. The sprayed area was chosen as a key indicator of cooling performance from the viewpoint of evaporation rate, which is well known to be proportional to the evaporation effect on the surface of the fin.
Options for CNVII emission legislation are being widely investigated in a national program organized by China Vehicle Emission Control Center (VECC) since early 2020. It is foreseen that this possibly last legislation in China will have more stringent emission requirements compared to CNVI, including further reduction of nitrogen oxide (NOx), inclusion of nitrous oxide (N2O) and sub-23 nm particle number (PN) and etc. This study investigates the technical feasibility to fulfill a CNVII emission legislation scenario, based on a modified CNVI 8 L engine operating under both cold and hot World Harmonized Transient Cycle (WHTC) and Low Load Cycle (LLC). Methods to address the challenges are discussed and validated, including a twin dosing system, electric heater, hybrid concept of combining Copper (Cu-), Iron (Fe-) and Vanadium (V-) SCR technologies, high filtration DPF and optimization of engine calibration and urea dosing strategies.
Exhaust gas recirculation technology is one of the main methods to reduce engine emissions. The pressure of the intake pipe of supercharged direct-injection diesel engine is high, and it is difficult to realize EGR technology. The application of Venturi tube can easily solve this problem. In this paper, the working principle of guide-injection Venturi tube is introduced, the EGR system and structure of a turbocharged diesel engine using the guide-injection Venturi tube are studied. According to the working principle of EGR system of turbocharged diesel engine, the model of guide-injection Venturi tube is established, the calculation grid is divided, and it is carried out by using Computational Fluid Dynamics method that the three-dimensional numerical simulation of the internal flow of Venturi tube under different EGR rates injection.
With the increasing number of hybrid vehicles in the Chinese market, research on aftertreatment system for hybrid vehicles has become very popular. China has currently issued national China6 regulations and also regulated the emissions of hybrid vehicles. So far, there are few reports on the optimization of aftertreatment for hybrid gasoline vehicles. Due to the involvement of electric motors in hybrid vehicles, the engine frequently starts lead to inconsistent stability of engine operating conditions and also bring the challenge to emission control of engine exhaust emissions. This article mainly selects a highly popular hybrid vehicle in China for research, which is a dual model hybrid (DM-hybrid) passenger car. There is a significant correlation between the emissions during the journey of driving and the hybrid strategy.
The target of the newly and future automotive emission regulations is to promote a fast transition to near-zero emission vehicles. As such, the range of ambient and operating conditions tested in the homologation cycles is broadening. In this context, the proposed work aims to thoroughly investigate the potential of post-oxidation phenomena in reducing the light-off time of a conventional three-way catalyst. The study is carried out on a turbocharged four-cylinder gasoline engine by means of experimental and numerical activities. Post oxidation is achieved through the oxidation of unburned fuel in the exhaust line, exploiting a rich combustion and a secondary air injection dedicated strategy. The CFD methodology consists of two different approaches: the former relying on a full-engine mesh, the latter on a detailed analysis of the chemical reactions occurring in the exhaust line.