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Technical Paper

X-Wing: A Low Disc-Loading V/STOL for the Navy

1985-10-01
851772
The X-Wing concept employs a single lifting system for all modes of flight. The lifting system is comprised of four very rigid, circulation control wings with blowing for lift modulation and control. For hover and low speed flight, the wings rotate such as the rotor of a helicopter. For high speed flight, the wings are stopped in an “X” configuration across the fuselage - from which the name of the concept is derived - with two forward-swept wings and two aft-swept wings. Such a vehicle is also envisioned to have an integrated gas turbine propulsive system for all flight modes. At low speeds, the gas generators) would drive a shaft to turn the wings and the circulation control compressor as well as a set of propulsive fans. For high-speed flight, the shaft would drive only the compressor and accessories as the fans propel the vehicle. The X-Wing concept has been underdevelopment for over 15 years.
Technical Paper

Yaw Rate Sensor for Vehicle Dynamics Control System

1995-02-01
950537
From the beginning of 1995 on, RB will start the production of the Vehicle Dynamics Control System. A key part of this system is the Yaw Rate Sensor described in this paper. The basic requirements for this sensor for automotive applications are: mass producibility, low cost, resistance against environmental influences (such as temperature, vibrations, EMI), stability of all characteristics over life time, high reliability and designed-in safety. Bosch developed a sensor on the basis of the “Vibrating Cylinder”. The sensor will be introduced into mass production in beginning of 1995.
Technical Paper

ZF Retarder in Commercial Vehicles

1992-11-01
922452
This paper describes the ZF - Intarder, a wear-free vehicle brake for commercial vehicles. Qualities such as optimum weight saving, compactness, compatibility with all PTOs and no change in driveshaft length, are the results of a new development. Performance measurements demonstrate connection with engine cooling system. Field test measurements provide new information about frequency of use of various brake levels and electronic speed control. An evaluation of financial issues indicates advantages for operation.
Technical Paper

Zero Dimensional Models for EGR Mass-Rate and EGR Unbalance Estimation in Diesel Engines

2017-09-04
2017-24-0070
A precise estimation of the recirculated exhaust gas rate and oxygen concentration as well as a predictive evaluation of the possible EGR unbalance among cylinders are of paramount importance, especially if non-conventional combustion modes, which require high EGR flow-rates, are implemented. In the present paper, starting from the equation related to convergent nozzles, the EGR mass flow-rate is modeled considering the pressure and the temperature upstream of the EGR control valve, as well as the pressure downstream of it. The restricted flow-area at the valve-seat passage and the discharge coefficient are carefully assessed as functions of the valve lift. Other models were fitted using parameters describing the engine working conditions as inputs, following a semi-physical and a purely statistical approach. The resulting models are then applied to estimate EGR rates to both conventional and non-conventional combustion conditions.
Technical Paper

Zero-Dimensional Spark Ignition Combustion Modeling - A Comparison of Different Approaches

2013-09-08
2013-24-0022
Internal combustion engines development with increased complexity due to CO2 reduction and emissions regulation, while reducing costs and duration of development projects, makes numerical simulation essential. 1D engine simulation software response for the gas exchange process is sufficiently accurate and quick. However, combustion simulation by Wiebe function is poorly predictive. The objective of this paper is to compare different approaches for 0D Spark Ignition (SI) modeling. Versions of Eddy Burn Up, Fractal and Flame Surface Density (FSD) models have been coded into GT-POWER platform, which connects thermodynamics, gas exchange and combustion sub-models. An initial flame kernel is imposed and then, the flame front propagates spherically in the combustion chamber. Flame surface is tabulated as a function of piston position and flame radius. The modeling of key features of SI combustion such as laminar flame speed and thickness and turbulence was common.
Technical Paper

Zero-Venting, Regenerable, Lightweight Heat Rejection for EVA Suits

2005-07-11
2005-01-2974
Future space exploration missions will require a lightweight spacesuit that expends no consumables. This paper describes the design and performance of a prototype heat rejection system that weighs less than current systems and vents zero water. The system uses regenerable LiCl/water absorption cooling. Absorption cooling boosts the heat absorbed from the crew member to a high temperature for rejection to space from a compact, non-venting radiator. The system is regenerated by heating to 100°C for two hours. The system provides refrigeration at 17°C and rejects heat at temperatures greater than 50°C. The overall cooling capacity is over 100 W-hr/kg.
Technical Paper

Zero-dimensional Modeling of Flame Propagation During Combustion of Natural Gas/Hydrogen Mixtures

2023-04-11
2023-01-0190
To achieve global climate goals, greenhouse gas emissions must be drastically reduced. The energy and transportation sectors are responsible for about one third of the greenhouse gases emitted worldwide, and they often use internal combustion engines (ICE). One effective way to decarbonize ICEs may be to replace carbon-containing fossil fuels such as natural gas entirely, or at least partially, with hydrogen. Cost-effective development of sustainable combustion concepts for hydrogen and natural gas/hydrogen mixtures in ICEs requires the intensive use of fast and robust simulation tools for prediction. The key challenge is appropriate modeling of flame front propagation. This paper evaluates and applies different approaches to modeling laminar flame speeds from the literature. Both appropriate models and reaction kinetic calculations are considered.
Technical Paper

Zinc Alloy Engine Components

1988-02-01
880286
The ZA series of zinc alloys produce high strength die castings with the same cast-to size capability as the well proven SAE 903 alloy. The enhanced properties have been utilised in the two engine components described in this paper. ZA 27 has been used for the tooth belt drive camshaft pulley of a motorcycle engine and ZA8 has been used for the temperature resistant housing of a car ignition distributor.
Technical Paper

Zinc Distribution in Vacuum Brazed Alclad Brazing Sheet

1978-02-01
780301
Vacuum brazing technology is currently capable of producing aluminum automotive heat exchangers such as radiators and heater cores. The possible use of 7072 claddings on the surfaces exposed to the coolant to provide additional corrosion protection is of considerable interest. This paper describes the effect of typical vacuum brazing cycles on the distribution of zinc in 7072 clad vacuum brazing sheet. For heavier gauges (.05″), there is sufficient retained zinc in the post-braze composite. For lighter gauges (.02″ or less), nominal composition 7072 does not provide adequate retained zinc; however, if the initial zinc concentration is increased to 3% there is sufficient retained zinc so that the cladding is significantly more anodic than the core.
Technical Paper

Zinc Soldered Copper and Brass Radiators: Their Processing and Their Test Results

1992-02-01
920177
Copper and brass radiators have served the automobile industry for many years using traditional fabrication processes. Demand for newer and stronger radiators with lighter weight for the modern vehicles prompted investigation of alternate materials. Properties of zinc alloys and their compatibility with brass suggested these could be used for radiator manufacture. Many zinc alloy compositions were investigated in the initial studies, because a solder alloy has to have many positive attributes. The first screening studies evaluated the ability of the solder to spread over copper and brass surfaces, representing tube, fin, and header materials. The second most important feature was the melting range of the developed alloy. In order to retain the anneal resistance of the fin and temper in the tube it was desirable to have a zinc solder with a melting temperature at 800°F or less.
Technical Paper

a progress report — Dry-Type Air Cleaners on Farm Tractors

1959-01-01
590026
GREATER ease of servicing is one of the ultimate goals in the development of dry-type air cleaners. The authors acknowledge, however, that the oil-bath cleaner is a rugged proved component that has done a good job for the farmers who serviced it properly. This paper describes studies made in Illinois of oil-bath and dry air cleaners in field service. At the same fuel/air ratios, the maximum horsepower of a test engine was greater with the dry-type filter than with the oil-bath cleaner. It was found that with AC fine dust and steady airflow, the oil-bath cleaners had significantly lower efficiencies than the dry-type filter. At less than rated airflow the efficiency of the oil-bath cleaner decreased while that of the dry filter remained high.
Technical Paper

a universal means for Rating Diesel Engines for Deposits and Wear

1960-01-01
600066
THE NEW CRC Diesel Engine Rating Manual is intended to furnish a universal language for identification of diesel-engine deposits and wear. Diesel-engine pistons are evaluated for lacquer deposits by utilizing an area demerit basis and color gradations of brown and gray from clean to black. In studying various means for evaluating thickness and texture of deposit in oil systems, it was decided that the scratch gage developed by the CRC Engine Deposit Rating Panel of the CRC-Motor Engine Varnish and Sludge Group was suitable for diesel engines. A procedure for establishing a volume factor which furnishes a weighted interpretation of the deposit was created.*
Technical Paper

and Repeatability of Transient Heat Release Analysis for Heavy Duty Diesel Engines

2009-04-20
2009-01-1125
Reduced emissions, improved fuel economy, and improved performance are a priority for manufacturers of internal combustion engines. However, these three goals are normally interrelated and difficult to optimize simultaneously. Studying the experimental heat release provides a useful tool for combustion optimization. Heavy-duty diesel engines are inherently transient, even during steady state operation engine controls can vary due to exhaust gas recirculation (EGR) or aftertreatment requirements. This paper examines the heat release and the derived combustion characteristics during steady state and transient operation for a 1992 DDC series 60 engine and a 2004 Cummins ISM 370 engine. In-cylinder pressure was collected during repeat steady state SET and the heavy-duty transient FTP test cycles.
Technical Paper

basic design of Turbochargers for diesel engines

1960-01-01
600007
ALTHOUGH turbocharging of low-speed diesel engines has been used world-wide for a long time, it is only during recent years that it has been applied to high-speed diesels. This is the result of considerable engineering efforts from both the turbocharger and the diesel side that were put into the turbocharger, which appears to be a so utterly simple device. This paper de­scribes some of these engineering efforts. The basic design characteristics are developed with the point of view in mind that the turbo­charger has become much more than just an ad­ditional accessory. It is a vital component of the basic engine itself, contributing actively to the advancement of this prime mover. The basic de­sign characteristics center heavily around aero­dynamical and thermodynamical performance cri­teria which are so important in any advanced high-speed turbomachine.
Technical Paper

considerations of some JET-DEFLECTION PRINCIPLES for - - directional control - - lift

1958-01-01
580062
THE performance characteristics of various devices applicable for jet directional control, lift augmentation, and VTOL-STOL studied at the NACA Lewis Laboratory are discussed, including jet deflection devices applicable to the conventonal round nozzle and novel nozzle configurations. The results indicate that many of the deflection devices applicable to conventional nozzles can readily be used for directional control or lift augmentation. Other deflection devices, such as movable plug, internal flap, cylindrical thrust reverser, swiveled primary with fixed shroud, and 90 deg side-bleed nozzle, are limited in application to jet directional control or aircraft trim because the loss in axial thrust for a given deflection force is prohibitive or the maximum deflected force obtainable is limited.
Technical Paper

eFMI (FMI for Embedded Systems) in AUTOSAR for Next Generation Automotive Software Development

2021-09-22
2021-26-0048
Nowadays automobiles are getting smart and there is a growing need for the physical behavior to become part of its software. This behavior can be described in a compact form by differential equations obtained from modeling and simulation tools. In the offline simulation domain the Functional Mockup Interface (FMI) [3], a popular standard today supported by many tools, allows to integrate a model with solver (Co-Simulation FMU) into another simulation environment. These models cannot be directly integrated into embedded automotive software due to special restrictions with respect to hard real-time constraints and MISRA compliance. Another architectural restriction is organizing software components according to the AUTOSAR standard which is typically not supported by the physical modeling tools. On the other hand AUTOSAR generating tools do not have the required advanced symbolic and numerical features to process differential equations.
Technical Paper

eROSITA Camera Low Temperature Thermal Control

2008-01-29
2008-01-1957
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is a powerful X-ray telescope under development by the Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany. eROSITA is the core instrument on the Russian SRG1 mission which is planned for launch in 2011. It comprises seven nested Wolter-I grazing incidence telescopes, each equipped with its own CCD camera. The mirror modules have to be maintained at 20°C while the cameras are operated at -80°C. Both, mirrors and CCDs have to be kept within tight limits. The CCD cooling system consists of passive thermal control components only: two radiators, variable conductance heat pipes (VCHP) and two special thermal storage units. The orbit scenario imposes severe challenges on the thermal control system and also on the attitude control system.
Technical Paper

knock-knock: Spark Knock, Wild Ping, or Rumble?

1959-01-01
590019
ENGINE noise has become an increasing problem with the higher and higher compression ratios of present-day automotive engines. Because fuel octane number cannot be raised indefinitely, the problem is one of engine design and selection of crankcase lubricating oils and gasoline formulations, the authors think. This paper describes investigations into the cause of spark knock, wild ping, rumble, and the added problem of hot-spot surface ignition (which also intensifies as compression ratios increase). The authors have found gasolines with phosphorous additives, used with properly formulated multiviscosity lubricating oils, provide a partial answer to the problem of engine rumble. The authors conclude that very exact tailoring of fuels, lubricants, additives, and engines will be necessary to prevent engine noise if compression ratios continue to rise.
Technical Paper

mDSF: Improved Fuel Efficiency, Drivability and Vibrations via Dynamic Skip Fire and Miller Cycle Synergies

2019-04-02
2019-01-0227
mDSF is a novel cylinder deactivation technology developed at Tula Technology, which combines the torque control of Dynamic Skip Fire (DSF) with Miller cycle engines to optimize fuel efficiency at minimal cost. mDSF employs a valvetrain with variable valve lift plus deactivation and novel control algorithms founded on Tula’s proven DSF technology. This allows cylinders to dynamically alternate among 3 potential states: high-charge fire, low-charge fire, and skip (deactivation). The low-charge fire state is achieved through an aggressive Miller cycle with Early Intake Valve Closing (EIVC). The three operating states in mDSF can be used to simultaneously optimize engine efficiency and driveline vibrations. Acceleration performance is retained using the all-cylinder, high-charge firing mode.
Technical Paper

p>Thermomechanical Analysis of the Cylinder Head and Cylinder Block with the Liner of AFV Diesel Engine

2011-10-06
2011-28-0118
This paper deals with the Coupled thermo mechanical analysis of a cylinder head, cylinder block and crank case with the liner of an uprated engine. The existing engine develops 780 hp output with mechanical driven supercharger and the engine is uprated to 1000 hp by replacing the supercharger with a turbocharger and new Fuel injection equipment. For uprating any engine, the piston and cylinder head are the most vulnerable members due to increased mechanical and thermal loadings. Mechanical loading is due to the gas pressure in the gas chamber and its magnitude can be judged in terms of peak pressure. Thermal loading is due to temperature and the heat transfer conditions in the piston surface, cylinder liner and the cylinder head. The relative importance of the various loads applied on the head and cylinder block in operation are assessed and a method of predicting their influence on the structural integrity of the components described.
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