The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Downsizing
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Influence of Port Water Injection on the Combustion Characteristics and Exhaust Emissions in a Spark-Ignition Direct-Injection Engine

Shanghai Jiao Tong University-Yadong Fan, Tianbao Wu, Xuesong Li, Min Xu, David Hung
  • Technical Paper
  • 2020-01-0294
To be published on 2020-04-14 by SAE International in United States
It is well known that engine downsizing is still the main energy-saving technology for spark-ignition direct-injection (SIDI) engine. However, with the continuous increase of the boosting ratio, the gasoline engine is often accompanied by the occurrence of knocking, which has the drawback to run the engine at retarded combustion phasing. Besides, in order to protect the turbine blades from being sintered by high exhaust temperature, the strategies of fuel enrichment are often taken to reduce the combustion temperature, which ultimately leads to a high level of particulate number emission. Therefore, to address the issues discussed above, the port water injection (PWI) techniques on a 1.2-L turbocharged, three-cylinder, SIDI engine were investigated.Measurements indicate that the optimization of spark timing has a significant impact on its performance. The two factors of the water substance itself and spark advance caused by the knock mitigation are trade-offs, which eventually affect the combustion performance. Under knock limited spark advance (KLSA) condition, we find that the application of port water injection could effectively advance the combustion phasing and reduce exhaust gas…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Power Control Unit for Compact-class Hybrid Vehicle

Toyota Motor Corporation-Toshio Ikeyama, Keitaro Ishikawa, Natsuki Nozawa
  • Technical Paper
  • 2020-01-0456
To be published on 2020-04-14 by SAE International in United States
Toyota Motor Corporation has developed the new compact-class hybrid vehicle (HV). This vehicle incorporates a new hybrid system for the improvement of fuel efficiency. For this system, a new Power Control Unit (PCU) is developed. The feature of the PCU is downsizing, lightweight, and high efficiency. In expectation of rapid popularization of HV, the aptitude for mass production is also improved. The PCU, which plays an important role in the new system, is our main focus in this paper. Its development is described.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Energy, Fuels, and Cost Analyses for the M1A2 Tank: A Weight Reduction Case Study

CCDC Ground Vehicle Systems Center-Rob Hart
EcoSpherica LLC-John L. Sullivan
  • Technical Paper
  • 2020-01-0173
To be published on 2020-04-14 by SAE International in United States
Reducing the weight of the Abrams M1A2 tank has been studied by lightweighting three separate components: hull, suspension, and track, resulting in 5.1, 1.3, and 0.6 percent tank mass reductions, respectively. The impact of replacing an existing with a lightweight component on tank performance are evaluated in terms of three metrics: primary energy demand (PED), cost, and tank operational fuel consumption (FC). The life cycle phases included are: preproduction, material production, part fabrication, and tank operation. The metrics for each of the tank lightweight components are expressed as ratios: for example, the sum of PED for the four life cycle phases of the lightweight tank / the PED for the operational phase only of the base case (unmodified) tank. For Army defined duty cycles, a FC/mass elasticity of 0.55 was employed for estimating changes in tank FC upon mass reductions. On a per tank basis, we find that the relative costs to retrofit and operate a tank with a lightweight hull ranges from 19 to 3.5 times those for simply operating (fuel costs) an existing…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Injection Strategy on the Combustion and Knock in a Downsized Gasoline Engine with Large Eddy Simulation

BAIC Motor Powertrain Co., Ltd.-Yan Li, Junjie Liang
Tianjin University-Ying Wang, Haiqiao Wei, Lei Zhou
  • Technical Paper
  • 2020-01-0244
To be published on 2020-04-14 by SAE International in United States
Strategies to suppress knock have been extensively investigated to pursue thermal efficiency limits in downsized engines with a direct-injection spark ignition. Comprehensive considerations were given in this work, including the effects of second injection timing and injector location on knock combustion in a downsized gasoline engine by large eddy simulation. The turbulent flame propagation is determined by an improved G-equation turbulent combustion model, and the detailed chemistry mechanism of a primary reference fuel is employed to observe the detailed reaction process in the end-gas auto-ignition process. The conclusions were obtained by comparing the data to the baseline single-injection case with moderate knock intensity. Results reveal that for both arrangements of injectors, turbulence intensity is improved as the injecting timing is retarded, increasing the flame propagation speed. It can be found that knock intensity is greatly affected by the location of the injector since the distribution of the end gas is determined by the direction of the fuel injection. In present study, when injector is mounted on the opposite side as the spark plug, double injection…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of New Power Control Unit with Small Size and Low Cost for Small Hybrid Vehicle with Two-motor Hybrid System

Honda R & D-Yuichiro Ueno, Yasuhiko Kondo
Keihin Corp.-Kenichi Nonaka, Kenichi Takebayashi, Yukiya Kashimura
  • Technical Paper
  • 2020-01-0458
To be published on 2020-04-14 by SAE International in United States
A new power control unit (PCU) has been developed for a Honda small hybrid vehicle with a two-motor hybrid system launched in 2020. For small hybrid vehicles, downsizing and reducing costs of hybrid systems are major challenges. As such, there were emphatic requirements for the newly developed PCU to be small and affordable. To satisfy these requirements for the PCU, new technologies and components have been introduced such as an all-in-one type intelligent power module (IPM) with integrated functions and reverse conducting IGBT (RC-IGBT), a new control sequence for voltage control unit (VCU), and revised PCU packaging to improve cooling performance. The new IPM has a printed-circuit board (PCB) equipped with an electric control unit (ECU) and gate drive circuits, 7 current sensors, and a power module with RC-IGBTs. This functional integration led to a reduction in the number of main electrical PCU assembly components from 9 in the previous PCU to 2 in the new PCU. In addition, the number of mounted parts on the PCBs was reduced from 2,200 to 1,300 by means…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Supercharging on the Intake Flow Characteristics of a Swirl-Supported Engine

China North Engine Research Institute-Yufeng Li
Tianjin University-Yizhuo Feng, Zhen Lu, Tianyou Wang, Junqian Cai, Pengfei Wei
  • Technical Paper
  • 2020-01-0794
To be published on 2020-04-14 by SAE International in United States
Although supercharged system has been widely employed in downsized engines, the effect of supercharging on the intake flow characteristics remains inadequately understood. Therefore, it is worthwhile to investigate intake flow characteristics under high intake pressure. In this study, the supercharged intake flow is studied by experiment using steady flow test bench with supercharged system and transient flow simulation. For the steady flow condition, gas compressibility effect is found to significantly affect the flow coefficient (Cf), as Cf decreases with increasing intake pressure drop, if the compressibility effect is neglected in calculation by the typical evaluation method; while Cf has no significant change if the compressibility effect is included. Compared with the two methods, the deviation of the theoretical intake velocity and the density of the intake flow is the reason for Cf calculation error. For the transient intake condition, such increase of intake flow velocity with increasing intake pressure was found to be valid only at low engine speeds (2000 rpm). At high engine speeds (4000 rpm), however, flow velocity remains almost unchanged regardless of…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Fretting Damage Analysis and Predicting of Engine Head and Block

Great Wall Motor Co., Ltd.-Rong Ye, Yuwei Han, Xiaowei Sun, Jianxiang Shi, Ying Guan, Guodong Zhao
  • Technical Paper
  • 2020-01-1167
To be published on 2020-04-14 by SAE International in United States
Today engine downsizing, weight reduction, boosting, etc. are widely used in modern combustion engine designs in order to increase power output, improve fuel economy, and reduce emission. However utilizing of these advanced technologies is making the engine less rigidity and resulting in potential fretting damages on any contact surfaces of engine components due to higher cyclic relative motions. The leakage failure of the cylinder-head sealing system induced by fretting damage on engine head and block deck surfaces is the one of major failure modes in the modern combustion engine. In this paper, the characteristics and failure modes of the MLS head gasket sealing system is introduced first. The fretting mechanism between MLS head gasket and engine head and block is then investigated and a fretting damage parameter and a damage criterion as well are defined and established to evaluate the crack nucleation or wear initiation. Also it is important to identify two types of loads during engine operation in the fretting damage calculation. The developed methodology is successfully verified through a good correlation between CAE…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigation of homogeneous lean SI combustion in high load operating conditions

Chalmers University of Technology-Kristoffer H. Clasen, Lucien Koopmans
  • Technical Paper
  • 2020-01-0959
To be published on 2020-04-14 by SAE International in United States
Homogeneous lean combustion (HLC) can be utilized to substantially improve SI ICE efficiency which is vital in the process of enabling clean, efficient and affordable propulsion for the next generation light duty vehicles. More research is however necessary to ensure robustness, fuel efficiency/ NOx trade-off and utilization of HLC. Utilization can be improved by expanding the HLC operating window to higher engine torque domains which increases impact on real driving. The authors have earlier assessed dedicated HLC boosting in a downsized 2lt engine but it was found that HLC operation could not be achieved above 15 bar IMEP due to instability and knock. The observation led to the conclusion that there exists a lean load limit. Therefore, further experiments have been conducted in a single cylinder research SI GDI engine to increase understanding of high load lean operation. HLC is known to suppress end-gas autoignition (knock) by decreasing reactivity and temperatures, but during the experiments knock was observed to be prominent and increasing in severity when engine load was increased despite operating ultra-lean close to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Exmani-Heat protector to Improve Sound Absorption using New Perforated Thin Aluminum Plate

Hyundai Motor Group-Jaegi Sim, Minsoo Kim, KwangMin Yoon
  • Technical Paper
  • 2020-01-0405
To be published on 2020-04-14 by SAE International in United States
This technology is a technology for reducing the gas flow noise generated from the noise of the vehicle, especially the exhaust system. The primary function of the heat protector is thermal shutdown. However, due to the increase in engine power, downsizing of engines, and the rise of consumer's eye level, solutions about noise are now emphasized. Established the manufacturing technology of 3-ply composite board which can absorb sound in the existing heat protector. For this purpose, mold technology for punching aluminum sheet, optimization technique for punching effect, unique high-strength / high-forming pattern design, sound absorbing material selection and composite sheet molding technology, and noise vibration reduction mounting technology for plate joining were developed.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

An Analysis of Diesel Spray Characteristics with Small Injection Amount under Similarity Law Condition

Graduate School of Engineering, Hiroshima University, Higash-Yu JIN, Chang ZHAI, Keiya NISHIDA, Yoichi OGATA
  • Technical Paper
  • 2019-32-0590
Published 2020-01-24 by Society of Automotive Engineers of Japan in Japan
In this paper, the Diesel spray characteristics were studied by HS video camera and the Laser Absorbing Scattering (LAS) technique means of the combustion deterioration problem caused by the engine downsizing based on the geometrical similarity was investigated. In the experiments, three Diesel injectors with the hole diameters of 0.07mm, 0.101mm and 0.133mm were used. The injection pressures of the injectors with three different diameters were 45MPa, 93MPa and 160MPa, respectively. The Diffused Background Illumination (DBI) method was employed for the nonevaporating spray experiment to obtain spray tip penetration and spray angle at room temperature. The LAS technique was employed for the evaporating spray experiment to obtain the equivalence ratio distributions, evaporation rate, and vapor phase tip penetration. Moreover, the Wakuri Momentum Theory was applied to analyze the data obtained by both the non-evaporating and the evaporating spray experiments. The non-evaporating results show that the spray tip penetrations scaled by the similarity law matched well from the injectors of different hole diameters. However, the scaled spray angle of the injector with smaller hole diameter is…
This content contains downloadable datasets
Annotation ability available