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Cylinder-kit tribology has been a significant focus in developing internal combustion engines of lower emission, reduced friction and oil consumption, and higher efficiency. This work addresses the impact of ring-groove geometry on oil (liquid oil and oil vapor) transport and combustion gas flow in the cylinder kit, using a dynamic three-dimensional multiphase modeling methodology during the four-stroke cycle of a piston engine. The ring and groove geometry, along with the temperature and pressure conditions at the interface between piston and liner, trigger the oil and gas (combustion gases and oil vapor) transport. A study of the second ring dynamics is presented to investigate the effect of negative ring twist on the three-dimensional fluid flow physics. The oil (liquid oil and oil vapor) transport and combustion gas flow processes through the piston ring pack for the twisted and untwisted geometry configurations are compared.

Brake squeal has been and remains a challenging issue to vehicle manufacturers due to its complicated interaction between structural dynamics and tribological aspects. A significant number of studies have been done previously either on structural dynamics or tribological aspects alone or combination of these two aspects. It is seen that very limited studies have been conducted to assess the contribution of grit particles or road particles which contains silica sand, dust, wear debris, airborne particle, granite and many more on brake squeal occurrences based on brake pad surface characterizations. Thus, this paper attempts to examine the effect of grit particles on brake pad surface topography and subsequently its correlation with squeal generation. In doing so, road grit particles with the size of 400-500 μm will be used and fed into the disc brake end corner.

A previously developed two-dimensional model of a vehicle in a lateral roll (Rose, et al. 2008) was used in this study to analytically evaluate the effect of vehicle roll angle and roll velocity on roof-impact ΔV and consequent occupant injury mechanism and risk. Both occupants adjacent to (near-side) and remote from (far-side) the rollover’s leading side were evaluated. Injury evaluation was limited to head and neck/spinal injuries. The vehicle’s roll angle at the time of roof-impact dramatically affected the local ΔV at the point of head-to-roof contact. Both roof-rail impacts may be injurious to far-side occupants, while near-side occupants are more likely to sustain head or neck injuries in roof impacts with the adjacent roof rail. Far-side occupants have a greater risk of compressive neck injury during impacts with the remote roof rail, while adjacent roof rail impacts subject occupants to primarily lateral head impacts with a higher head injury risk.

A review of available information on the effect that brake rotor crossdrilling has on brake performance reveals a wide range of claims on the subject, ranging from ‘minimal effect, cosmetic only’ to substantially improving brake cooling and fade resistance. There are also several theories on why brake rotor crossdrilling could improve fade performance, including crossdrill holes providing a path for ‘de-gassing’ of the brake lining material and increasing the mechanical interaction, or ‘grip’ of the lining material on the rotor. This paper reviews three case studies in which the opportunity arose to compare the performance of brake systems with crossdrilled versus non crossdrilled brake rotors in otherwise identical brake corner designs. The effect of brake rotor crossdrilling on brake cooling, brake output, brake fade, wet brake output, and brake wear rates were studied using both on-vehicle and dynamometer data.

Improvements in disc brake friction and wear characteristics are usually sought by alternating the disc pad composition or processing conditions. This study investigated the effects of varying the cast iron rotor chemistry and microstructure on the performance and wear resistance of a disc brake composed of such rotors and standard commercial semi-metallic disc pads. A statistical design of an engineering experiment was used to determine such effects of five chemical variables of the cast iron rotor -- C, Si, Mn, P and Ti -- and two processing variables -- solidification and cooling rates. An increase in manganese or phosphorus content improved brake performance and decreased pad wear, compared to a standard chemistry cast iron. Cast irons with high titanium or carbon levels showed low friction and high pad wear. Improved performance but high pad wear were found for cast irons with high silicon contents.

Finite element analysis of suspension coil springs is standard practice for investigating spring behavior during compression. One increasingly important aspect of spring behavior under recent demand is precise control of the spring's force line. Proper control reduces side loading on the damper assembly, which increases ride comfort. The force line is the reaction force axis produced by a coil spring and its interaction with the spring seats during compression. Not only does the geometric configuration of the spring and seats affect the force line, but it has also been seen experimentally that the spring seat material has an effect. Elastomeric materials such as rubber are used in spring assemblies to reduce noise, vibration, and harshness (NVH), but their influence to spring force line axis has yet to be investigated. The construction and results of several finite element simulations will be presented, correlating various configurations and experimental data.

Traditionally, door seals are designed to achieve good wind noise performance, water leakage and door closing effort in a vehicle design and development process. However, very little is known concerning the effect of door seal design on vehicle squeak and rattle performance. An earlier research work at Ford indicates a strong correlation between the diagonal distortions of body closure openings (in a low frequency range 0 - 50 Hz) and overall squeak and rattle performance. Another research at Ford reveals that relative accelerations between door latch and striker in a low frequency region (0 - 50 Hz) correlate well with door chucking performance. The findings of this research work enable engineers to assess squeak and rattle and door chucking performance using vehicle low frequency NVH CAE models at a very early design stage.

Secondary injection in a diesel engine is defined as the introduction of additional fuel into the combustion chamber after the end of the main injection. It is usually caused by residual pressure waves in the high-pressure pipe line connecting the pump and injector. When these waves exceed the injector opening pressure, secondary injection occurs. Tests revealed that the U.S. Army TACOM single-cylinder engine used in this investigation, fitted with an American Bosch injection system, had secondary injection within the normal engine operating region. The pump spill ports and delivery valve were redesigned to eliminate secondary injection, in accordance with previously reported work. Comparative tests of both the conventional and modified injection systems were run on the same engine, and the effects of secondary injection on engine power, economy, and exhaust emissions were determined.

Rotary engines, by design, are somewhat more difficult to cool than conventional reciprocating powerplants. This arises in apart from the fact that all four cycles do not take place within the same physical portion of the engine. The basic aim of this research was to study the metal temperatures of many points in the rotary engine with standard and experimental coolants in an attempt to develop a product with superior heat rejection properties in a conventional cooling system. The engine used for the experiment was a two-rotor liquid-cooled Wankel engine obtained from a 1972 Mazda R-100. Both road and chassis dynamometer evaluations were run over a wide range of operating conditions to obtain a comprehensive look at coolant performance. The parameters studied for each coolant were road speed, engine load, coolant concentration, and ambient temperature; the coolants tested were ethylene glycol, water, and the experimental coolants XA-1318L and XA-1318.1L.

The performance, combustion and NO emission characteristics of a naturally aspirated, DI diesel engine having selected parts of the combustion chamber insulated were investigated experimentally and analytically. In this study two insulation schemes, namely insulation of the piston crown and insulation of the cylinder head, using thin ceramic thermal barrier coatings, are compared with the baseline engine (no coatings). Experiments under different operating conditions of load, speed and injection timing for the baseline engine and the two insulation schemes were conducted. The experimental results showed that insulation of the piston crown is more effective than insulation of the cylinder head in improving the brake specific fuel consumption (BFSC) and NO emission of the engine Compared to the baseline engine, coating the piston crown lowered the NO emission under all operating conditions and consistently improved BSFC at the highest load and highest speed test conditions.

Cooled EGR is recognized as a solution for the reduction of NOx in diesel exhaust gas. The key component of cooled EGR is a tubular type heat exchanger, however the performance drops because of particulate deposition whose characteristics and mechanism are not clrealy understood. Therefore the requirements for a EGR cooler is not only higher heat exchange performance and lower pressure loss, but also less performance deterioration due to DEP (Diesel Exhaust Particulate) deposition known as fouling. In order to improve heat transfer performance of an EGR cooler, it is considered that the surface with riblets aligned in the flow direction is preferable for the heat transfer surface because of its less skin friction and heat transfer enhancement. To apply riblet design to EGR coolers, however, it is necessary to investigate the performance with fouling from diesel particulate.

The automatic transmission clutch represents a complex system involving critical interactions between the separator plates, fluid, operating conditions and friction material. This paper focuses on the effect of separator plate flatness on the performance and durability of two friction materials on an SAE #2 machine. The data from this study shows that flat separator plates yield higher dynamic coefficients and lower wear when compared to non-flat plates. These effects were obtained for separator plates with peak-to-peak departure from flatness values between approximately .08mm and .25mm. In addition, other variables such as material elastic modulus, separator plate thickness, and material operating pressure were studied. The use of soft friction materials to improve performance with non-flat reaction plates was quantified.

The viscosity of engine lubricants was measured at multiple shear rates by a unique Scanning Brookfield apparatus. These oils included both Pumpability Reference Oils (PRO) and a selection of today's commercial multigrade oils. It was found that the viscosity of “flow-limited” oils remained constant when the shear rate decreased. Oils with “air-binding” properties exhibited an increase in viscosity with decreasing shear rate. The magnitude of a change in “slope of the temperature/viscosity profile was found to suggest the degree of air-binding character of an oil. The flow characteristics of PRO 1, 3, 9, 11, and 16 were measured at several shear stresses and temperatures in the Mini-Rotary Viscometer. The Scanning Brookfield technique and the Mini-Rotary Viscometer were found to yield similar results when the shear stress of the Mini-Rotary Viscometer was reduced from 525 to 35 Pascals.

The DPF(Diesel Particulate Filter) has been established as a key technology in reducing diesel PM emission. Also Catalyzed-DPF Systems are viewed as the next generation DPF System in the automotive sector, replacing the current Fuel Additive System. The performance requirements of the DPF-equipped vehicle are good fuel economy, good driving performance, high PM regeneration performance of accumulated soot and high durability. In this paper the effect of Catalyzed-DPF characteristics, such as porosity, pore size, cell structure and catalyst loading have been defined on pressure drop, filtration efficiency, regeneration efficiency and regeneration behavior.

The risk of sustaining injury in side collisions is correlated to collision severity as well as other factors such as restraint usage and occupant position relative to the impact. The most recent National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) data available (1997 to 2007) were analyzed to identify accidents involving passenger vehicles that have experienced an impact with a principal direction of force (PDOF) either between 8:00 and 10:00 or between 2:00 and 4:00, indicating a side impact collision. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants who were at least sixteen years old and were seated in the outboard seating positions of the front row. These data were further analyzed to determine injury risk based on resultant delta-V, restraint system use, and occupant position relative to the impact.

The effect of small amounts of silicate on coolant performance has been studied. The corrosion protection provided by different coolant technologies was evaluated for different silicate contents. This work includes results from electrochemical tests and static and dynamic heat-rejecting tests on aluminum surfaces. The results indicate that small amounts of silicate have a negative effect on the corrosion protection of aluminum. Depletion of silicates can therefor be expected to affect aluminum heat-rejecting surfaces. The use of carboxylic acid corrosion inhibitors can overcome this problem.

Laboratory and field testing of silicone brake fluid, over a period of twelve years, has shown no adverse effects on braking systems while many advantages are apparent. The near complete conversion by the American Automotive Industry, to rayon reinforced, neoprene tube and cover brake hoses caused some concern with the compatibility of silicone fluid and this type hose. Data is presented comparing conventional fluids and silicone fluid and the effect of each on hoses from several manufacturers.

High strength sheet steels continue to be used in automobile structural components for mass reduction. Depending on the metallurgical strengthening mechanism used in these steels, short term, high-temperature excursions such as those which might be encountered in welding or heating for flame straightening during body repair could reduce their strength. To study this effect, time-temperature cycles were obtained on instrumented automobile rail sections during typical repair procedures using flame heating and welding. These data were then used to generate a program for heat treating tensile specimens of selected steels intended to cover a range of steels used which could be applied to automobile structural components. Crush tests were also performed on simulated rail sections of these steels after undergoing flame heating and welding. Tensile tests showed some degradation of strength for a lean-chemistry dual phase steel and of ductility for galvanized steels.

The effects of physical motion and vehicle responsiveness on driver performance were investigated with a moving-base driving simulator. Twenty-four subjects were divided into four motion conditions ranging from no motion to roll plus yaw plus attenuated lateral translation. Each motion group drove the simulated vehicle with three levels of tire cornering stiffness. The presence of motion reduced driver control activity and path keeping deviations, but the effects of changing vehicle responsiveness were not disguised by reducing the number of motion cues. The results suggest, however, that motion cues become more important as driving maneuvers become more extreme.

Water-atomized nickel-molybdenum alloy (0.5 Ni-0.5 Mo) powder was blended with graphite for 0.4% carbon, then pressed into preforms (1.5 X 2 X 5 in). The preforms were hot formed to full density via a variety of processing conditions (various degrees of flow, sintering temperature, and sintering atmosphere). Impact specimens were excised and tested over a range of temperatures to determine the ductile-to-brittle transition temperature. All impact specimens had ductile failure at room temperature. In general, increased deformation increased the room-temperature and low-temperature impact strengths by eliminating particle boundaries and elongating the inclusions. High temperature sintering reduced the oxygen content and improved the impact strength by reducing the number of crack-initiating inclusions. Jominy hardenability test results were unaffected by various sintering conditions because the amount of easily oxidizable alloying elements was kept to a minimum.