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Vulcan XC 72R was modified in two different ways (i.g., treated by the NH3 gas or urea). The impact of modification strategies was analyzed by correlating the structure and chemical properties of carbons with the catalytic activity and stability of corresponding catalysts. Pt clusters are homogeneously distributed through the nitrogen-doped carbon support. Electronegative nitrogen atoms create positive charge on neighbor carbon atoms. The increased interaction between the carbon support and PtCl62- restrains the nucleation of platinum. N2 adsorption-desorption results indicated that abundant of micropores were created and the proportion of micropores obviously increased from 2.8 % to 11.4 %. XPS measurement distinguished different N functionalities. Pyridinic-N and pyrrolic-N were introduced on the surface of carbon support. Pt/NC catalyst exhibits the best ORR performance among all as-prepared catalysts in 0.1 M KOH solution.

Frontal collision is the leading cause of passenger vehicle occupant death in the recent years. Active safety systems like automatic emergency braking has been demonstrated to be able to mitigate frontal collision or to reduce collision impact. However, braking is not as effective as steering when host vehicle is at high speed, since it typically requires more minimum safety distance for braking than for steering to avoid a frontal collision. Evasive steering assist (ESA) is designed to improve driver’s steer maneuver in the case of a potential imminent front collision with another vehicle or VRU. If driver initiates a steering maneuver but that steering input is not enough to avoid the collision, then evasive steering assist will kick in to apply an additional steering in the direction of the driver’s input, to help driver complete the evasive steering maneuver stably and safely.

Study of the spray formation in vicinity of the nozzle is essential to better understand and predict the physical processes involved in the diesel atomization. The initial spray patterns were found to be different from one injection to another during our visualization experiments, which was carried out based on a long distance microscope with a high speed camera in this work. It was found that the initial spray might contain a clear single mushroom, tail region and intact liquid column, or have a tail in front of the mushroom without changing its direction. Occasionally, it presented as a double-mushroom shape, or did not include a clear mushroom. Our visualization results showed that the various spray structures were observed at different injection pressures and different injection cycles under the same injection pressure.

This paper outlines a real-time hierarchical control allocation algorithm for multi-axle land vehicles with independent hub motor wheel drives. At the top level, the driver’s input such as pedal position or steering wheel position are interpreted into desired global state responses based on a reference model. Then, a locally linearized rigid body model is used to design a linear quadratic regulator that generates the desired global control efforts, i.e., the total tire forces and moments required track the desired state responses. At the lower level, an optimal control allocation algorithm coordinates the motor torques in such a manner that the forces generated at tire-road contacts produce the desired global control efforts under some physical constraints of the actuation and the tire/wheel dynamics. The performance of the proposed control system design is verified via simulation analysis of a 3-axle heavy vehicle with independent hub-motor drives.

Advanced high strength steels (AHSS) are particularly attractive to automotive industry. Stamping AHSS parts, however, results in accelerated die wear problems which could emerge after few thousands of stampings. The existing wear testing methods are either not suitable for charactering die wear in stamping or requires significant capital investment. The first generation of strip-on-cylinder wear test apparatus which can efficiently and economically characterize die wear is introduced in this paper. Different measurement methods were compared and white light interferometer with nanoscale accuracy was chosen to determine the wear volume due to its overall advantages. Based on the strip-on-cylinder wear test apparatus, a design of experiments study analyzing the effects of contact pressure, sliding speed and hardness of the die material on die wear was conducted and the results were discussed.

This research focuses on the injury potential of children seated in forward facing child restraint seats during frontal vehicle crashes. Experimental sled tests were completed in accordance to the Federal Motor Vehicle Safety Standard 213 using a Hybrid III three-year-old dummy in a five point child restraint system. A full vehicle crash test was completed in accordance to the Canadian Motor Vehicle Safety Standard 208 with the addition of a three-year-old Hybrid III crash test dummy, seated behind the passenger seat, restrained in the identical five-point child safety seat. Different child restraint finite element models were developed incorporating a subset of the apparatus used in the two experimental tests and simulated using LS-DYNA.

Piston design that incorporates the heat pipe cooling technology may provide a new approach for piston-temperature control. A simulated piston crown that contains an annular reciprocating heat pipe is developed to investigate the effect of heat pipe cooling on the piston crown temperature distribution. For this purpose, a reciprocating engine testing apparatus is designed and constructed. The experimental study focuses on the static and dynamic operational characteristics of the heat pipe and its cooling effect on the simulated piston crown under different power input. The experiment results indicate that a piston crown incorporating a heat pipe can yield a uniform temperature distribution in the ring-bank area of the piston crown. The testing results would also provide the needed information for a possible piston design that incorporates the heat pipe cooling technology for improved thermal-tribological performance.

The first part of this series of papers reports the development of a simulated piston crown with an annular reciprocating heat pipe and the investigation on the effect of heat-pipe cooling on the piston-crown temperature distribution. This paper presents the modeling of the simulated piston crown with the finite-element method and the analysis of its thermal performance. The heat-transfer coefficient with respect to the reciprocal environment of the experimental apparatus and the effective thermal conductance of the annular heat pipe are determined by correlating the modeling with the experimental measurements. The numerical modeling agrees well with the experimental results. The analyses indicate that the heat-pipe cooling technology can provide an effective means for piston temperature control.

An engine piston cooling method incorporating shaking-up heat pipes (SUHPs) is described. In shaking-up heat pipes, the liquid return from the condenser to the evaporator section is achieved by a high-frequency shaking-up action. In addition, the liquid splash and impingement on the inner surface facilitate temperature uniformity along the heat pipe. The concept of the SUHP is verified by experimental observation of a transparent heat pipe and thermal testing of a copper/water SUHP. A comparative thermal analysis on the SUHP and gallery cooling systems is performed. The approximate analytical results show that the piston ring groove temperature can be significantly reduced using the heat pipe cooling technology, which may contribute to an increase in engine thermal efficiency and a reduction in environmental pollution.

An increase in the temperature of charge in an engine combustion chamber is now more and more attractive due to its advantages in energy savings and environmental control. However, this will affect the design of engine elements, since a higher temperature will result in considerable thermal stresses and distortion, material and lubricant degradation, or even seizure and scuffing failures. Actually even for currently designed diesel engines, engine piston assembly failure, particularly piston ring/cylinder liner interface failure due to heat accumulation, is a very serious problem. Effective means of carrying heat away from this area are crucial for the prevention of scuffing. However, due to the reciprocal motion of the mechanism, efficient piston cooling is difficult to achieve using conventional cooling methods.