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The fit of a spacesuit has been identified as a crucial factor that will determine its usability. Therefore, because one-size-fits-all spacesuits seldom fit any wearer well, and because individually tailored spacesuits are costly, the University of Maryland has conducted research into a resizable Extravehicular Activity (EVA) suit. This resizing is accomplished through a series of cable-driven parallel manipulators, which are used to adjust the distance between plates and rings built into a soft space suit. These actuators, as well as enabling passive suit resizing, could be used to actively assist the astronaut's motion, decreasing the torques that must be applied for movement in a pressurized suit. This paper details the development and testing of an arm prototype, which is used to better understand the dynamics of a more complex torso-limb system.

A SULEV proposal was investigated for a Hyundai Elantra 1.8L Nu Engine, combining advanced catalyst technologies with optimized engine management control. A washcoat system using 20% less PGM loading and an optimized EMS calibration were developed to meet the 50% development target of the LEV III SULEV30 standards. This paper highlights revisions made to the new control and catalyst systems which include, 1) improved light-off time and cold-start emissions, 2) optimized cold lambda control, 3) reduced number of fuel cut events, 4) a new catalyst technology to match exhaust gas characteristics, and 5) a Pd-only front catalyst with reduced PGM.

A coupled steady-state CFD and thermal study was undertaken at full-vehicle scale using the Low-Reynolds formulation of the k-epsilon turbulence model, with hybrid wall function modification. The separate thermal model included radiative and conductive heat transfer. Road testing (simulated hill climb using towing dynamometer) was performed to provide both boundary conditions for exhaust temperature and detailed local temperatures (air and surface) to enable correlation. CFD and thermal models were alternately iterated until overall convergence was achieved. Measured air temperatures were utilized in the “control” thermal model to provide a best possible non-CFD solution. Coupled model results show reduction in local surface temperature prediction error due to the inclusion of the detailed convection modeling, but cause concerns that the heat transfer mechanism in the exhaust tunnel is not correctly represented.

Today, downsizing through active displacement control is in series production using cylinder deactivation (CDA) concepts. However, current systems deactivating two cylinders of a four-cylinder engine are limited regarding the effective CO2 saving potential due to the confined usable operating range of the two-cylinder mode. Therefore, the objective of the current investigation is a three-cylinder engine with the possibility to activate an additional (fourth) cylinder. For this purpose, a four-cylinder series engine was modified to the firing order of a three-cylinder engine for the first three cylinders. The exterior cylinders 1 and 4 are operated in parallel, with the fourth cylinder deactivated in efficiency mode. Launching and idle mode are also operated with three active cylinders. Additional modifications to the valve train were carried out in order to further exploit the increased residual gas tolerance due to the load point shift.

The spray characteristics of a single-fluid pressure-swirl outward-opening DISI injector, with a nominal operating fuel pressure of 20 MPa. are presented for various ambient pressure and temperature conditions. These data include the experimental investigations of the spray structure and its temporal development with the aid of the imaging technique; PDA measurements of the temporal evolution of the droplet size - velocity characteristics; and the LIF-PLIF measurements of the spray liquid- and-vapor phases development. The experiments pertain to atmospheric and elevated ambient air conditions (P = 0.1 - 1.2 MPa., T = 20.° - 400.° C), representative of turbo-charged and high EGR engine operating conditions. This injector is incorporated in a single-cylinder DISI engine in a “narrow-spacing” arrangement that adopts a spray-guided air-assisted stratified-charge combustion concept, labeled “direct injection spray and air controlled” (DISAC) combustion system.

In previous study, a method of combustion detection for homogeneous charge compression ignition (HCCI) using a crank angle sensor and a knock sensor has been estimated [1]. In addition, an ion-current sensor has been used as a countermeasure against abnormal combustion with downsizing and higher compression ratio engines. An ion-current sensor has been newly adopted in engine systems. In this study, detection performance of combustion conditions in HCCI and spark ignition (SI) using with the ion-current sensor was estimated. The purpose of this study was to confirm detectable combustion conditions using with the ion-current sensor, and to confirm a requirement of applied voltage for the ion-current sensor. A detection signal of the ion-current sensor was changed by combustion style (HCCI,SI). Experimental results showed a heat release rate increased with ion signals increasing approximately at the same time in HCCI and SI.

This paper describes a study of the exhaust aerosols produced by a single cylinder Onan diesel engine using a rapid dilution sampling system. Diluted exhaust aerosols were analyzed with an electrical aerosol analyzer (EAA) and a transmission electron microscope. Mass concentrations of particulate matter were determined by gravimetric filter analysis. Volume mean diameters observed with the EAA were about 0.1 μm. Mass concentration measurements made with filters were in qualitative agreement with those calculated from the aerosol volume concentrations measured with the EAA.

In-cylinder process of a direct injection (DI) compression ignition (CI) engine was studied by using the Rutgers high-speed spectral infrared (M) imaging system and the KIVA-II computer code. Comparison of the engine measurements with the computational prediction was attempted. In order to perform the instantaneous IR imaging, a Cummins 903 engine cylinder head was modified by installing an optical access in place of one of the intake valves, which required designing a new rocker-arm mechanism. The measurements obtained using the highspeed dual spectra IR imaging system were processed by the conventional two-color method which employed soot as the radiating target. The KIVA-II program was coded in order to match engine and operation conditions to those employed in the present measurements for achieving mutual consistency of the analysis.

In an automotive air-conditioning (AC) system, upfront prediction of the cabin cool down rate in the initial design stage will help in reducing the overall product development (PD) time. Vehicle having higher seating capacity will have higher thermal load and providing thermal comfort to all passengers uniformly is a challenging task for the automotive HVAC (Heating Ventilation and Air conditioning) industry. Dual HVAC unit is generally used to provide uniform cooling to a large cabin volume. One dimensional (1D) simulation is being extensively used to predict the HVAC performance during the initial stage of PD. The refrigerant loop with components such as compressor, condenser, TXV and evaporator was modeled. The complicated vehicle cabin including the glazing surfaces and enclosures were modeled as a three row duct system using 1D tool AMESim®. The material type, density, specific heat capacity and thermal conductivity of the material were specified.

The US Army Research Laboratory performed a failure investigation on a broken main landing gear mount from an AH-64 Apache attack helicopter. This “infinite-life” component had failed in flight, and initially prevented the helicopter from safely landing. In order to avoid a catastrophe, the pilot had to perform a low hover maneuver to the maintenance facility, where ground crews assembled concrete blocks at the appropriate height to allow the aircraft to safely touch down. The failed part was fabricated from maraging 300 grade steel (2,068 Mpa [300 ksi] ultimate tensile strength), and was subjected to visual inspection/light optical microscopy, metallography, electron microscopy, energy dispersive spectroscopy, chemical analysis, and mechanical testing. It was observed that the vacuum cadmium coating adjacent to the fracture plane had worn off and corroded in service, thus allowing pitting corrosion to occur.

The agricultural combine harvester is one of the most complex of machines used in cereal grain production. It is believed that significant increases in efficiency and productivity could be realized if several of the machine adjustments could be automatically controlled. One of the most important parameters to measure and control is the feedrate, i.e. the mass flow rate of material entering the machine. This paper reports on an investigation of a sensor, using electrical capacitance techniques, to measure feedrate.

A full scale wind tunnel test was performed with a general aviation aircraft to investigate the use of the slipstream momentum survey method as a means of measuring propeller thrust in flight. Aircraft angle of attack is shown to have significant influence on the momentum measurements. Thrust values obtained from the slipstream momentum correlated well with overall aircraft force measurements; however, insufficient data regarding the slipstream static pressure variation resulted in a systematic error in the results. The need for detail static pressure measurements in the slipstream is demonstrated.

This paper summarizes an investigative study done to evaluate the feasibility of a Ford Duratec engine in 2.0 L Touring Car Racing. The investigative study began in early 1996 due to an interest by British Touring Car Championship and North American Touring Car Championship sanctioning bodies to modify rules & demand the engine be production based in the vehicle entered for competition. The current Ford Touring Car entry uses a Mazda based V-6. This Study was intended to determine initial feasibility of using a 2.0 L Duratec V-6 based on the production 2.5L Mondeo engine. Other benefits expected from this study included; learning more about the Duratec engine at high speeds, technology exchange between a production and racing application, and gaining high performance engineering experience for production engineering personnel. In order to begin the Duratec feasibility study, an initial analytical study was done using Ford CAE tools.

Lean burning in piston engines gives opportunity to achieve important enviromental and fuel economy objectives. Unfortunately, lean mixtures are not readily ignited and are characterized by poor flame propagation. Thus, techniques which enhance ignition, flame formation and its propagation must be applied, if lean combustion is to be reliably sustained. To overcome difficulties related to the lean burning, it has been proposed to equip the engine cylinders with prechambers, containing catalytic inserts, shaped in form of an open coil. The coils not only facilitate ignition but also generate turbulence, to intensify the combustion process in prechamber. A four-cylinder Diesel engine has been adapted for experiments aimed at confirmation of the effectiveness of the catalytic action on operation of the system.

An articulated vehicle suspension comprising a parallel combination of passive energy restoring and dissipative elements and a feedback controlled force generator is analyzed using H2 control synthesis. The active suspension schemes based on limited-state measurements are formulated to minimize a performance measure comprising ride quality, cargo safety, suspension and tire dynamic deflections, and power requirements. The ride quality and the dynamic wheel load performance characteristics of these suspension schemes are compared to those of a vehicle with an ideal active suspension and an “optimum” passive suspension to demonstrate the performance potentials of the proposed limited-measurement-based suspension schemes.

Scarce resources of fossil fuels and increasingly stringent exhaust emission legislation push towards a stronger focus to alternative fuels. Natural gas is considered a promising solution for small engines and passenger cars due to its high availability and low carbon dioxide emissions. Furthermore, natural gas indicates great potential of increased engine efficiency at lean-burn operation. However, the ignition of these lean air/fuel mixtures leads to new challenges, which can be met by fuel scavenged prechambers. At the Institute of Internal Combustion Engines of the Technische Universitaet Muenchen an air cooled natural gas engine with a single cylinder displacement volume of 0.5 L is equipped with a methane scavenged prechamber for investigations of the combustion process under real engine conditions. The main combustion chamber is supplied with a lean premixed air/fuel mixture.

In the present work, bio-diesel produced from Thevatia Peruviana seed oil which is commonly called as Yellow oleander is blended with diesel to investigate the performance and emission characteristics of a naturally aspirated diesel engine. The testing is carried out under 8-mode testing cycle used for off-road vehicles. The extracted bio-oil is subjected to gas chromatography-mass spectrometer to obtain its fatty acid profile. It is then converted into bio-diesel by transesterification process. The properties of bio-diesel produced are conforming to EN14214 standards except for a slightly lower density. Two blends of B10, B15 with diesel are used for experiments. The reduction in power and torque is observed to be proportional to increasing blend ratio. Results show that there is a reduction of 15.71% of CO and 32.30% reduction in HC for B15 blend compared to base line diesel. However, CO2 and NOX emissions are found to be increased for blends as compared to baseline engine.

A new latent heat storage technique for space applications developed by the DLR-ITT uses LiF as the storage medium in graphite capsules with internal capillary notches to accomodate the volume change upon melting. The receivers of solar dynamic power systems (SDPS) may contain a large number of heat pipes carrying annular such storage capsules for very effective heat transfer and thermal storage. The thermal behavior of one of these heat-pipe/latent-heat-storage elements was investigated theoretically and shall be verified experimentally, both in a geometrically and energetically 1:1 scale with respect to a 25 kWe SDPS. This paper summarizes the most important theoretical predictions and describes the planned experiment. The theoretical results show that the required heat flows are essentially achievable but subject to variation with the state of charge of the heat storage units. The relevant temperatures vary in a similar manner.

An important source for soot formation during the combustion of diesel engines with direct injection is the interaction of liquid fuel or a very rich air/fuel-mixture with the flame. This effect appears especially in modern direct injection engines where the injection is often split in a pre- and a main injection due to noise reasons. After the ignition of the pre-injected fuel a part of the main injection can interact with the flame still in liquid phase as the fuel is injected straight towards the already burning cylinder areas. This leads to high amounts of soot. The injection strategy for this experimental study overcomes this problem by separating the injections spatially and therefore on the one hand reduces the soot formation during the early stages of the combustion and on the other hand increases the soot oxidation later during the combustion. In particular an injection configuration is used which gives the degree of freedom to modify the injection in the described manner.

A new steering method to improve control during cornering is examined using a driving simulator, and the following findings were obtained. During cornering, there is a danger that it is not possible to finish curving is course out by the only differentiation steering. However, the driver can easily maintain a drift in the drift area when assisted by differentiation steering, and the behavior of the return to a straight course becomes stable. Therefore, since a remarkable effect was expected by controlling the steering method corresponding to the running condition, an examination experiment was performed. The shapes of the waves of initial steering at start up differ according to the running condition, and as a result, initial steering of the steering wheel is a two-step motion in J-turn running. In contrast, smooth steering proceeds without steps in the lane change running.