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In an attempt to increase efficiency and lower critical and highly regulated emissions (i.e., NOx, PM and CO2) many advanced combustion strategies have been investigated. Most of the current strategies fall into the category of low temperature combustion (LTC), which allow emissions mandates to be met in-cylinder along with anticipated reduction in cost and complexity. These strategies, such as homogeneous charge compression ignition (HCCI), premixed charge compression ignition (PCCI), partially premixed combustion (PPC) and reactivity controlled compression ignition (RCCI), use early injection timings, resulting in a highly lean charge with increased specific heat ratios to improve thermal efficiency and reduce PM emissions. Lower combustion temperatures also avoid the activation of NOx formation reactions.

Solutions developed by Chih-Bing Ling in two dimensional elasticity are used to investigate stresses in a perforated strip under pure tension. Results of a strain gage test show close correlation with the two dimensional theory of elasticity. A series of curves are plotted to show the effects of stress for various configurations of hole size, hole spacing, and strip width. Areas of investigation are between the holes and at ninety degrees to the tensile axis.

In commercial vehicle, Leaf Spring design is an important milestone during product design and development. Leaf springs are the most popular designs having multiple leaves in contact with each other and show hysteresis behavior when loaded and unloaded. Commonly used methods for evaluation of leaf spring strength like endurance trials on field and Rig testing are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation give useful information early in the design cycle and save considerable time and cost. They give flexibility to evaluate multiple design options and accommodate any design change early in development cycle. A study has been done in Volvo-Eicher to correlate Rig result with Finite Element Analysis (FEA) simulation result of Multi-stage Suspension Leaf Spring, entirely through Finite Element Analysis route.

In commercial vehicle, Leaf Spring design is an important milestone during product design and development. Leaf springs are the most popular designs having multiple leaves in contact with each other and show hysteresis behavior when loaded and unloaded. Commonly used methods for evaluation of leaf spring strength like endurance trials on field and Rig testing are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation give useful information early in the design cycle and save considerable time and cost. They give flexibility to evaluate multiple design options and accommodate any design change early in development cycle. A study has been done in Volvo-Eicher to correlate Rig result with Finite Element Analysis (FEA) simulation result of Multi-stage Suspension Leaf Spring, entirely through Finite Element Analysis route.

The increasing interest in the application of Large Eddy Simulation (LES) to Internal Combustion Engines (hereafter ICEs) flows is motivated by its capability to capture spatial and temporal evolution of turbulent flow structures. Furthermore, LES is universally recognized as capable of simulating highly unsteady and random phenomena driving cycle-to-cycle variability (CCV) and cycle-resolved events such as knock and misfire. Several quality criteria were proposed in the recent past to estimate LES uncertainty: however, definitive conclusions on LES quality criteria for ICEs are still far to be found. This paper describes the application of LES quality criteria to the TCC-III single-cylinder optical engine from University of Michigan and GM Global R&D; the analyses are carried out under motored condition.

The final interior noise of a vehicle is due to the contribution of several sub-systems sources and their transmission paths (airborne and structure-borne) to the driver's ear. Ford Motor Company had developed a Windows based software using simple noise path analysis to estimate the final vehicle level acceleration noise. Measurement data of several sub-system components were inputted to software that computed the airborne and structure-borne contributions in 1/3-octave and order spectra to give the final vehicle interior noise level. The predicted noise was compared to the measured one and model was validated. Then, observing the frequency range of the boom phenomenon, it was possible to identify the main contributors. Still using the same tool, a new component target was set.

An off-road direct injection diesel engine equipped with a catalyzed diesel particulate filter (DPF) was subject to two sets of experiments in which two fuels, ultra low sulfur diesel (ULSD) and 20 vol. % biodiesel blend (B20) were compared. In the first set of experiments lubricant oil consumption was measured by sulfur tracing. In the second set of experiments nanoparticle formation downstream of the DPF was assessed. It was found that number concentration of nanoparticles released from the catalyzed DPF depends on fuel type and on engine operating condition and hence the onset of filter regeneration. For low soot loading times B20 fueling produces lower number concentrations, whereas longer soot loading times produce lower number concentrations with ULSD fueling.

The emissions impact associated with increasing gasoline sulfur content was investigated using eight late-model vehicles, most of which were equipped with advanced emission control systems and certified as California Low-Emission Vehicles. The effect of returning to operation on low-sulfur fuel on emissions was also investigated. Vehicle testing was performed using California Phase 2 Certification test fuels with nominal sulfur levels of 40 and 540 ppm in combination with the LA4 and US06 driving cycles. In addition to exhaust emission measurements, engine-out emissions, air-fuel ratio, catalyst composition, and catalyst temperature data were collected. The data showed that most of the vehicles were sensitive to gasoline sulfur content as emissions increased when the vehicles were operated on the higher-sulfur test fuel; however, the degree of sensitivity varied from vehicle to vehicle.

Hydrogen-fueled internal combustion engines (H₂ICEs) are an affordable, practical and efficient technology to introduce the use of hydrogen as an energy carrier. They are practical as they offer fuel flexibility, furthermore the specific properties of hydrogen (wide flammability limits, high flame speeds) enable a dedicated H₂ICE to reach high efficiencies, bettering hydrocarbon-fueled ICEs and approaching fuel cell efficiencies. The easiest way to introduce H₂ICE vehicles is through converting engines to bi-fuel operation by mounting a port fuel injection (PFI) system for hydrogen. However, for naturally aspirated engines this implies a large power penalty due to loss in volumetric efficiency and occurrence of abnormal combustion. The present paper reports measurements on a single-cylinder hydrogen PFI engine equipped with an exhaust gas recirculation (EGR) system and a supercharging set-up.

The commercial vehicles market is dominated by manual transmission, due to lower ownership cost. Generally, commercial vehicles are used in large numbers by the fleet owners. The transmission endurance life is very important to a vehicle owner. On the other hand, driver fatigue can be reduced with a smooth gear change process. The gear change process in a manual transmission is carried out with the help of the synchronizer pack. The crucial function of a synchronizer pack in an automotive transmission is to match the speed of the target gear for smooth gear shifting. In a transmission, the loose and the weakest part is the synchronizer ring. The failure of the synchronizer affects smooth gear shifting and it also affects the endurance life of the transmission. The synchronizer ring can fail due to poor structural strength, synchronizer liner wear, synchronizer liner burning, etc.

THOR-AV 5F, a modified THOR-5F dummy, was designed to represent both upright and reclined occupants in vehicle crashworthiness studies. The dummy was evaluated in four test conditions: a) 25° seatback, 15 km/h, b) 25° seatback, 32 km/h, c) 45° seatback, 15 km/h, d) 45° seatback, 32 km/h. The dummy’s biomechanical responses were compared against those of postmortem human subjects (PMHS) tested in the same test conditions. The latest National Highway Traffic Safety Administration (NHTSA) BioRank method was used to provide a biofidelity ranking score (BRS) for each data channel in the tests to assess the dummy’s biofidelity objectively. The evaluation was categorized into two groups: restraint system and dummy. In the four test conditions, the restraint system showed good biofidelity with BRS scores of 1.49, 1.47, 1.15, and 1.79, respectively.

A review is made of the various approaches considered in trying to develop an instrument capable of detecting CAT ahead of an aircraft. Because of the widespread regions in which CAT can occur and its often limited size, an airborne instrument is felt to be necessary to provide the pilot with sufficiently accurate and timely data to permit appropriate action to be taken to minimize its effect on the aircraft. While progress has been understandably slow, the outlook is not as black as it was a few years ago and the interest and efforts of many more people plus advances in technology enhance the possibilities of finding a solution to the CAT problem.

Loop Heat Pipes have been shown to be reliable, self-starting, high capacity heat transport devices which offer significant performance improvements over conventional heat pipes. They are also capable of both constant and variable conductance operation, providing both temperature control and heat transport functions. Two different Loop Heat Pipes were tested to characterize their temperature control capabilities. Operation in both a passive, autoregulating mode and an active control mode were investigated. The test results demonstrate that temperature regulation in each mode is attainable. The effects of the operational environment on temperature control characteristics were found to be important and are discussed.

The present work investigates the temperature distribution inside the diesel particulate filter (DPF) regeneration during the drop to idle test (DTIT), which is considered as life-threatening to the DPF. To study this scenario in detail, experiments were carried out with the filter volume of 3 liters. Initially, the experiments were done at a steady-state level, where the optimization for optimal soot loading was performed with setpoint temperature varying from 620 to 660°C. The soot loading was varied from 8 g/l to 11 g/l. The DTIT performed at a steady-state level indicated the different peak temperatures attained inside the DPF at different locations. The peak temperature was found to be in the center plane of the filter. The next peak temperature locations were found to be in downstream of the filter at different locations, which shows the non-uniformity in the soot deposition inside the filter.

Loop heat pipes (LHP) combine the classical heat pipe operation principle with a loop configuration, i.e. evaporator and condenser are located at separate places as dictated by thermal and configurational reasons and are connected lines for fluid and vapor transport. Experimental investigations of such LHP revealed certain temperature oscillations under certain conditions. This paper presents the results of analyses of such temperature fluctuations and offers possible explanations for initiation and termination of such behavior. Two types of temperature fluctuations have also been confirmed experimentally by testing different kinds of LHP.

The purpose of this paper is to find a way to extend the high load limit of homogeneous charge compression ignition (HCCI) combustion. A newly developed rapid compression and expansion machine (RCEM) was employed to reproduce the typical HCCI high load condition. The in-cylinder turbulence was created by the special piston which equipped with a flow guide plate. Meanwhile, the ambient temperature distribution in the cylinder was determined by the wall temperature controlling system which was controlled by the independent coolant passages. In addition, the numerical simulation by using large eddy method coupled with a detailed chemical reaction was conducted as well. The results show that HCCI mode is potential to be improved at high load condition in full consideration of in-cylinder temperature, flow, and turbulence.

The thermal characteristic of nanofluid for flow in a micro-channel is reported in this study by using an array of temperature nano-sensors. In this study, K-Type Thermocouples (Chromel/Alumel) were fabricated by surface micromachining process on a silicon wafer to obtain the thin film thermocouple array (TFTA). The micro-channel with TFTA was mounted on a heater (calorimeter) for imposing a specified heat flux on the bottom surface of the micro-channel. De-ionized water (DIW) was used as the test fluid for recording the temperature profile on the wafer substrate at different flow rates and heat fluxes. Aqueous nanofluids containing alumina nanoparticles were then used to record the temperature profiles under similar heat flux and flow conditions. The temperature profile was measured with the TFTA in a linear array of 5 columns and 2 rows of sensors while the volume flow rate was varied from 5 μl/min, to 7 μl/min and to 9 μl/min.

We have developed a new test method in which temperature of cavity lip of a piston alone during engine rotation is reproduced, cavity lip strain is measured. As the results of strain measurement using the test method in a condition that simulates of conventional engines, a strain behavior was out-of-phase. And in a condition that simulates of high-load engines in future, strain behavior was clockwise-diamond cycle. It was found from the result of the test method developed that strain increased on the cavity lip. The fatigue life of the cavity lip was evaluated using the strain measured and isothermal fatigue curves which obtained by the strain controlled isothermal fatigue test. The result of engine durability test has revealed that the developed method was valid for thermal fatigue evaluation of the cavity lip.

Titanium alloy (Grade V) is used in aerospace, medical, marine and chemical processing industries. To improve the thermal shock resistance and corrosion resistance of the titanium alloy at elevated temperatures, Thermal barrier coating (TBC) has been predominantly used. Cerium oxides (CeO2) have been proposed as TBC, due to their high thermal expansion coefficient, higher thermal shock resistance and low corrosion rate. In this study, CeO2 was coated on Titanium alloy by magnetron sputtering. Deposition time was varied as 30 mins, 60 mins and 90 mins respectively, to achieve the variation in thickness of coating. Thickness of the coated specimen was measured by atomic force microscopy and found to be 500 nm, 120 nm and 80 nm respectively. Surface roughness of the corresponding coated surfaces is 152.28 nm, 18.41 nm and 18.65 nm. The Vickers hardness was found to increase with decrease in coating thickness upto certain extent then decreases.

Thermal testing of spacecraft electronic units prior to flight provides effective detection of design, process and workmanship defects. Thermal testing subjects units to cold and hot thermal environments beyond those expected in flight. The strength of screening effectiveness depends upon the number of cycles, the temperature range, and the temperature transition rate. MIL-HDBK-344 provides insight into the incurred stresses and quantitative value (precipitation efficiency) of the screening environment using these three test parameters. In this paper, MIL-HDBK-344 topics applicable to thermal testing of space hardware are summarized and comparisons are made between test environment strengths computed from MIL-HDBK-344 and MIL-STD-1540E. The weighting of these aforementioned test parameters in the precipitation efficiency equation are discussed and assessed.