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This paper outlines a transient wave mechanism from an impact machinery such as punch press via computational and experimental methods. Results from the boundary element method to predict the transient acoustic field are compared with experiment by use of the fiber-optic surface acoustic intensity probe. The computational method combines an explicit and implicit methods to enhance the numerical stability and accuracy. The fiber-optic surface acoustic intensity probe which combines optical fibers and microphone will be discussed to illustrate the validity of the experimental method and hence numerical results. The improvement of the acoustic intensity probe performance will also be discussed to eliminate the phase error at higher frequency measurement and to increase the sensitivity and linearity. The comparison of the results will be described to demonstrate the capability and accuracy of the methods to identify the transient noise source generated from the impact noise.

One of the challenges in lubricant development is to adequately model performance across a broad range of potential lubrication and wear regimes that are encountered in use. Since wear in a given application is dependent on both rolling and sliding speeds, it is desirable to determine lubricant performance as a function of these variables. The use of a new test machine and methodology permits the construction of performance maps which define the transitions between lubrication regimes - hydrodynamic/elastohydrodynamic (EHD), EHD/mixed film and mixed film/boundary. This paper describes a method of mapping out the performance of a lubricant over a range of rolling and sliding velocities. Lubrication and wear performance is characterized for an ester base reference fluid (Herco-A) and two commercially available gear oils based on a petroleum oil and a poly(alpha olefin).

Although considerable research has been performed to quantitatively compare the relative fire-resistance afforded by different hydraulic fluids in various industrial applications, new standards reflecting these developments is still incomplete. The objective of this paper is to provide an overview of the classical tests that have, and are currently, used to quantify relative fire safety of fluids. This will be complemented by a discussion of recent test developments that could be incorporated into future standards.

The selection of a proper fluid to be used in a hydraulic system is an important part of any design effort. The hydraulic fluid must normally transmit, transform, and control the power from the system input to the output. In addition, the fluid is expected to provide lubrication and antiwear protection to many of the other components in the system. Although there are at least 22 parameters which describe a hydraulic fluid, most of these parameters are well defined. However, the antiwear and lubrication properties of a hydraulic fluid deserve more discussion. There are several test methods which have been developed to assess the antiwear properties of liquids. Most of these procedures are intended to evaluate fluids other than those directed toward use in a hydraulic system. This paper will present a bench type wear test method designed to overcome the recognized problems of other wear test procedures.

The focus of this paper is the interpretation and application of the Multipass Filter test- more commonly known as the Beta test for determining a filters (or medias) Beta Rating. A specific Beta test report is deserved and analyzed. A review of the required test equipment for conducting a Multipass test is provided and many test operating conditions are described. The Beta Rating definition and detailed points for conducting a Beta test are also given.

In order to remain competitive, organizations are reviewing their operations to determine ways to reduce their operating and maintenance costs. It has been estimated that the costs associated with equipment failures and malfunctions in the mobile fluid power industry in the United States reaches billions of dollars each year. It has been reported that contamination accounts for 70% of equipment failures, and this is an area where substantial savings can be made. system reliability is directly related to the amount of contamination in the system and improvements can only be made by having improved fluid cleanliness levels brought about by correctly applied and specified filters. This paper presents the necessity for manufacturers and users to develop a “Total Cleanliness Control” program. This program addresses equipment requirements for a specified level of cleanliness of components ranging from the initial fabrication stages through to in-service operation.

This paper addresses upgrading a connecting rod bearing trip function from pneumatic to electronic. Existing pneumatic systems use a eutectic element and a shutdown valve connected to a common header. When a connecting rod bearing trip occurs, the crankcase doors must be removed to find the tripped valve. The electronic connecting rod bearing trip system allows the user to remotely monitor the status of each connecting rod bearing trip. This paper will address performance requirements, alternative designs and prototype testing performed to ensure the satisfactory performance of the new equipment.

The power output of the emergency diesel generators at Consolidated Edison's Indian Point-2 Nuclear Generating Station has been increased in order to accommodate increased safety equipment electrical loads. The kilowatt rating of each of the three diesel generators was upgraded from 1750 KW to 2300 KW. The upgrade consisted of mechanical and electrical modifications to the engines, generators and ancillary equipment. The Emergency Diesel Generators are nuclear safety related systems. Parts and components were provided in accordance with Consolidated Edison's Specification for Nuclear Safety Related Systems.

The advent of the microprocessor has revolutionized technology worldwide with digital (microprocessor based) systems found throughout industry. While digital systems have been used in nuclear safety-related applications, uniform methodology has not been followed, precipitating regulatory guidance. While acknowledging the advantages of digital technology, the U.S. Nuclear Regulatory Commission (NRC) has noted that potential failure modes not previously considered are introduced with its application. Adapting traditional supply methodology is necessary to address design and quality assurance issues related to the common mode failure potential of computer software and electromagnetic interference. A participatory approach is described to apply a digital speed governing system to nuclear emergency diesel generators. This governing system is a proposed replacement for existing mechanical and analog electronic governing technology.

The objective of this study was to observe and attempt to understand the effects of equivalence ratio and simulated exhaust gas recirculation (EGR) on the exhaust emissions and performance of a L-head single cylinder utility engine. In order to isolate these effects and limit the confounding influences caused by poor fuel mixture preparation and/or vaporization produced by the carburetor/intake port combination, the engine was operated on a premixed propane/air mixture. To simulate the effects of EGR, a homogeneous mixture of propane, air, and nitrogen was used. Engine measurements were obtained at the operating conditions specified by the California Air Resources Board (CARB) Raw Gas Method Test Procedure. Measurements included exhaust emissions levels of HC, CO, and NOx, and engine pressure data.

A gaseous fuel emission control system which includes a three-way catalyst for the after treatment of exhaust gases has been developed for a 398 cc, four-stroke, air-cooled, spark ignition, overhead valve utility engine. The fuel delivery system utilized analog closed-loop air/fuel ratio control to maintain a narrow operating band about the stoichiometric air/fuel ratio. Using liquified petroleum gas (LPG) as the fuel, carbon monoxide emissions tested per CARB modal weighting factors were reduced by 98% and HC + NOx were reduced 62%. The emission levels were below the CARB 1995 Iimits. The emission control system shows considerable promise for controlling carbon monoxide emissions for indoor applications. The system was developed for gaseous fuels only where the engine can be run at the stoichiometric air/fuel ratio.

This paper reports on the preliminary investigation of the identification of a method to model the transient operation of a single cylinder four-stroke gasoline engine. During a transient the response of an engine and the actual fuel mixture delivered to the engine are significantly affected by the behaviour of the fuel injected into the inlet manifold. In the past, different wall-wetting theories have been developed to model and attempt to resolve this problem and one of the most definitive is investigated here along with two other theories developed at QUB. A steady state computer model of a single cylinder four-stroke spark-ignition research engine was written and validated. The three different wall-wetting theories were studied and each individually integrated into the steady state model. This allowed simulated transients to be performed on the computer and the results generated to be compared with firing transient tests.

Southwest Research Institute (SwRI) converted two small air-cooled, gasoline engines to operate on LPG (sometimes called propane since propane is LPG's major constituent). Typical two- and four-cycle engines were chosen for this investigation. The two-cycle engine used was a McCulloch string trimmer engine with 28 cc displacement. The four-cycle engine used was an L-head, Tecumseh TVS90 with 148 cc displacement. These are typical of engines found on lower cost lawn mowers and string trimmers. The engines were baseline tested on gasoline, converted to LPG, and tested to determine equivalence ratios at which the engines could be operated without exceeding manufacturers' recommended spark plug seat or exhaust temperatures. Engine startability and throttle response was maintained with the LPG conversion. The emissions of the four-cycle engine were measured following the CARB 6-mode emissions test procedure.

Stricter environmental regulation of used oils and fluids requires that extensive testing be done before recycling or disposal. Heavy metals, chlorinated solvents and PCBs are the primary analytes of concern. A variety of analytical methods exist, ranging from complicated laboratory analyses such as gas chromatography/mass spectroscopy to simpler field methods that provide fast, qualitative results. Depending on the type of fluid being tested and the method of disposal or recycling for the fluid in question, the cost of testing can run from five dollars per sample to several thousand dollars per sample. Knowledge of available testing techniques can significantly lower the cost of complying with these complicated regulations. Waste lubricating oil is a valuable resource that can return much of its value when re-refined for reuse or when burned for energy recovery.

Environmental awareness and environmental legislation have resulted in a new evaluation for base oils for technical applications. Biodegradable fluids like synthetic esters or plant oils have been developed which show considerable promise as a hydraulic pressure media. These fluids offer a good lubricity, good corrosion protection and compatibility with other materials. In response to the growing interest in environmentally acceptable fluids, performance data, laboratory evaluation and test experience for a vegetable based hydraulic fluid will be presented, identifying performance strengths and weaknesses in comparison to petroleum based fluids.

Many options exist for the recycling of wastes from off-highway operations. Parts cleaning can be done using solvents that are recycled over and over, with regularly scheduled servicing, possibly as non-hazardous waste. Used oil recycling might involve making sure the oil goes to a re-refiner and then using re-refined lubricants. Reclamation and reuse is a good option for antifreeze and segregated industrial solvents. Even for more complex wastes, such as oil filters and mixed liquid wastes, there are opportunities to reclaim the recyclable solvent and metallic portions of the waste, while blending the remainder for cement kiln fuel. The end result is that almost nothing goes for land disposal. This not only satisfies waste minimization requirements, but eliminates long-term liability for future environmental releases from the disposal site.

Exhaust gases from internal combustion engines contain appreciable quantities of various hydrocarbons and carbon monoxide. Solid carbon formed by decomposition of these gases on tribosurfaces could replace circulating lubricating oil, especially in low heat rejection engines. Experiments with silicon nitride in a pin-on-disc tribometer operating at 520°C, 2.2GPa contact pressure and 4.4cm/s sliding speed have demonstrated that friction and wear can be reduced by over 90% of their unlubricated values when ethylene, acetylene, and carbon monoxide and hydrogen are directed into the contacts. The lubricating deposit composition and morphology have been evaluated and compared in terms of effectiveness.

Electrorheological (ER) fluids have received a great deal of attention in the past decade. The promise of valves with no moving parts and simple damping devices have led many scientists to investigate this intriguing technology. Typically, though, these materials have exhibited shortcomings due to low strength and a narrow temperature range of operation. Recent advances in electrorheological fluid technology, as well as in the development of magnetic analogs to electrorheological fluids have led to the availability of controllable fluids that exhibit high strength, low viscosity and stability over a broad temperature range. This paper discusses the properties exhibited by these “new” electrorheological and magnetorheological (MR) fluids, as well as the feasibility of using these fluids in a variety of controllable devices.

A quasi-dimensional, two-zone combustion model was developed for calculating the formation of nitrogen oxides in direct-injection diesel engines. The model was verified by means of measurements obtained with two direct-injection, four-stroke, single-cylinder diesel engines, one of which had a total displacement of 3.96 liters and the other 5.95 liters. The combustion model was used to analyze the thermal dynamics and reaction kinetics of the procedures involved in well-known methods for the engine-internal minimization of nitrogen oxides.

Computerisation of Classical Engine Design Techniques using Spreadsheets. A.C.Erskine, R.Ali, G.G.Lucas, A.Hughes. Traditionally, engine components have been analysed using models with sufficient simplification to enable solutions to be calculated by hand. With the increasing availability of powerful computers these ‘classical’ techniques are being forgotten in favour of more accurate, but more complex and time consuming, finite element methods. This paper discusses the benefits of using classical analysis techniques and describes a user-friendly, spreadsheet based system for their application. The Classical Engine Design System (CEDS) is quick and simple to use making parametric studies in the early design stages easy. These can be used to evaluate the feasibility of a design in order to justify time and money spend on further, more detailed analysis. Microsoft's Excel spreadsheet package, running on a P.C., has been used as a basis for the software.