Search Results

A comprehensive computer simulation has been developed to predict the transient performance of a rotary engine. An adiabatic throttling process has been assumed to account for crevice leakage. The simulation has been tuned to fit experimental data obtained from tests upon a NORTON NR 601 engine. The potential of the model as an aid to engine design and development is illustrated by means of predictions of the effects of changes in some of the design parameters.

The three-dimensional computer code, KIVA, is being modified to include state-of-the-art submodels for diesel engine flow and combustion. Improved and/or new submodels which have already been implemented are: wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo'vich NOx, and spray/wall impingement with rebounding and sliding drops. Progress on the implementation of improved spray drop drag and drop breakup models, the formulation and testing of a multistep kinetics ignition model and preliminary soot modeling results are described. In addition, the use of a block structured version of KIVA to model the intake flow process is described. A grid generation scheme has been developed for modeling realistic (complex) engine geometries, and initial computations have been made of intake flow in the manifold and combustion chamber of a two-intake-valve engine.

The authors present a methodology to establish correlation, derived from experimental activities, for both heat release law and mechanical loss components in a turbocharged four-cylinder diesel engine. The introduction of the resulting parameters in a fully theoretical model leads to an improvement in its predictive level, as demonstrated by the result presented in terms of both thermodynamic and mechanical engine features. The most interesting characteristic of the model is represented by the comprehensive description of the engine dynamics under transient conditions.

Numerical simulations of in-cilinder processes were performed in order to study influence of different source data for computer model of diesel engine operation. Calculations were fulfiled on different levels: air-fuel spray, thermodynamics processes in combustion chamber and engine output parameters. Comparision of calculated and experimental results on all levels allows selection of reasonable values of source data. So we can obtain parameters of spray and in-cylinder processes near to real ones.

The System Theory considers every engineering problem as a corresponding mathematical model with input and output spaces and usually with a controller. By the same token, it is presumed that an appropriate model has been constructed. It is known that methods applied in this theory are effective for linear or naturally linearizable mathematical models. This paper is designed to convince the reader that a mathematical background in System Theory for input-output models is helpful for a wider class of technical problems. Also it seems to be important for development and approbation of System Theory methods to apply them to some new admissible objects. It turns out, that the basic ideas of System Theory can be applied to complicated physical optimizational problems connected with heat and mass transfer (with working process of diesel engines in particular).

This paper introduces a laboratory-developed tester for the front suspension of off-highway dump trucks. In dump truck movement at jobsites, the front suspension system is subjected to three-way load, i.e. in the vertical, horizontal and turning (steering) directions. Using three actuators, controllers and a computer, we conducted a lab simulation of such loads. With this tester, various quality assurance tests were carried out to provide reliable data in a short period of time. These tests were as follows: (1) Performance test to measure suspension characteristics such as spring stiffness, damping coefficient and internal friction (2) Stress measurement test to confirm structural strength (3) Endurance test to confirm durability and longevity of parts subject to wear, such as seals and bushings (4) Temperature environmental test to confirm sealing performance across a very low to high temperature range (5) Dust environmental test to confirm sealing performance against dust

The ISO 8178 Draft for Particulate Measurement of Off-Highway Diesel engines specifies partial-flow dilution systems as the preferred measurement equipment. Two critical points of such systems are presented in this paper: First, the correct implementation and/or determination of exhaust sampling and dilution ratio within the accuracy limits of ISO 8178. Second, the influence of size, length and temperature conditioning of the transfer tube and tunnel on particulate formation, deposition and re-entrainment. As a result of our investigations, recommendations for the proper layout of a partial-flow dilution system are given. Such a system will yield particulate emission values closely following the values obtained with a full-flow CVS system, where engine size permits the comparison. Where the engine size precludes the full-flow dilution, a particulate test equipment with proven correlation to a CVS system should be used

Komatsu's bulldozer D65 has undergone a full-scale model change for the first time in 22 years into a new model D65-12. This new model bulldozer has been developed to comply with the company's desired design philosophy “Friendly to People, Kind to People”. A “Revolutionary” advancement was achieved in comparison with the conventional ones which were developed and improved by producers' focus on productivity and economical efficiency. This model change not only has allowed production of a new-age bulldozer equipped with “Strength” and “Friendly to People”, but also has created a new turning point in Komatsu's bulldozer development. To realize this new bulldozer development, a number of new technologies and patents have been devised and put to practical use. This paper presents Komatsu's design philosophy and major new bulldozer technologies put to practical use.

This paper addresses the subject of engines for non coal non-gassy mine applications and presents a proposal for worldwide harmonized emission standards. Diesel-powered equipment is extensively utilized in underground hard rock and coal mines. This is due, to a great extent, to the efficiency and safety characteristics of the Diesel engine. Regulations are in place addressing the emission quality of these engines. Furthermore, sufficient mine ventilation must be provided in order to ensure that pollutant levels in the working environment don't exceed permissible levels. Historically, Diesel engines featuring Indirect Injection (IDI) combustion systems have been preferred for underground mining operation due to their cleaner exhaust gas characteristics. The ever increasing stringency of the emission requirements applicable to on-highway trucks has resulted in Direct Injected (DI) Diesel engines with emission characteristics equal to, or in some areas, better than IDI engines.

This paper introduces two new types of basic components (an Electro-Hydraulic Tube and a Hydraulic Tube) which when connected in an appropriate manner can control flow and pressure for many applications; in addition, one of the devices is readily interfacable to a microprocessor for external control. Some background information about the basic concept and the operation of the two components is introduced. Some of the experimental characteristics will be illustrated and several basic circuit examples will be presented to show how the concept can be implemented. The Electro-Hydraulic Integrated Block (EHIB) and Circuit (EHIC) will be introduced followed by a discussion of the advantages and potential of the EHIC concept.

The development of high precision flow divider/combiner valves has received considerable attention by the authors over the past decade. Several different valve designs for division and combination of flow have been designed which display small flow dividing/combining error (1-2%) when compared to conventional designs (2-10%). Recent studies have improved upon the design in order to reduce cost, weight and complexity of the valve. This paper will present the latest of the authors research into the development of a high precision, autoregulated flow divider/combiner valve with an integral shuttle valve. The autoregulator extends the operating range of the integrated flow divider/combiner valve (for errors less than 2 %) to 10-50 lpm compared to 30-50 lpm for the unregulated valve.

Anaerobic digestion is a popular method of treating sewage sludge. Biogas or sewage gas is a by-product of this process. Significant volumes of biogas are produced at many sewage treatment works and also at some landfill sites from the natural breakdown of municipal waste. This biogas can be used as a fuel for an engine and generating set, producing electrical power and heat. A multi-cylinder two-stroke cycle system, capable of being retrofitted to current production four-stroke cycle engines, is proposed, primarily for the combustion of biogas in combined heat and power applications. The engine incorporates features to give good tolerance to the corrosive agents associated with biogas. This paper describes the design and initial development of a purpose built single cylinder research engine to investigate this concept. A low pressure direct injection system which has been developed for use with the engine is also outlined.

In two previous papers to this Society (1, 2)* an ‘alternative’ method was presented for the prediction of the unsteady gas flow behaviour through a reciprocating internal combustion engine. The computational procedures led further to the prediction of the overall performance characteristics of the power unit, be it operating on a two- or a four-stroke cycle. Correlation with measurements was given to illustrate its effectiveness and accuracy. In the ducts of such engines there are inevitably sectional changes of area which are either gradual or sudden. A tapered pipe is typical of a gradual area change whereas a throttle or a turbocharger nozzle represents a sudden area change. In those previous papers it was indicated that a fuller explanation, of the theoretical procedures required to predict accurately the unsteady gas flow in such duct sections would be given in a later paper to this Society; this is that necessary publication.

Electronics technology has evolved significantly since the first electronically controlled heavy duty on-highway truck engines were introduced in the mid 1980's. Engine control hardware, software, and sensor designs have been driven by many factors. Emissions regulations, fuel economy, engine performance, operator features, fleet management information, diagnostics, vehicle integration, reliability, and new electronics technology are some of those factors. The latest engine electronics technology is not only found in heavy duty on-highway trucks, but in off-highway applications as well. Track-type tractors, haul trucks, wheel loaders, and agricultural tractors now benefit from the advantages of electronic engines. And, many more new applications are being developed.

Hydraulic shock, the banging sound or jumping hoses that occur when a hydraulic valve is used to start, stop, or change a hydraulic actuator's direction or speed, can be eliminated with a new electronic valve. Parker Hannifin's DigiValve® contains an onboard microcomputer that controls the time needed to change an actuator's direction and speed, thereby eliminating shock problems. The DigiValve can replace two or three existing valves in a typical hydraulic system, including a directional control valve and one or two flow control valves. The DigiValve uses the same voltage level signals as a solenoid-operated directional control valve to change direction, and onboard speed controls to replace manual adjustments of the flow control valves.

The development of thick film rheostat position and pressure senders, including justification, is described. Predecessor wire wound constructions with problems leading to thick film senders are also reviewed. Thick film's advantages of long life and consistency are covered as well as disadvantages. Later, issues relative to function and quality become evident in the data presented. Load conditions covered include environment, cycling, vibration and dither. Specific applications to pressure and fuel senders are described with historical results. Concluding, successful performance of thick film rheostat construction is established. The benefits expected are found validated, particularly with substantially improved service life.

This paper will discuss the conceptual integration of satellite tracking used for engine diagnostics for remote power generation sets. The significant application of this integration of technology is the capability to diagnose, monitor, make on-line adjustments and maintain complete control of the generation sets miles from their remote locations. The intended purpose for this technology is to assist the operator in the duty of performing diagnostics and monitoring when not physically located near the power unit. Applications for diagnostics through satellite tracking are widespread. However, certain land-based power generation applications are more likely than others to lend themselves to this method of monitoring. Oil field pumping units, continuous and standby remote generations sets and large scale traffic control/hazard lights used in highway construction zones can all benefit from this technology.

Proportional raise and lower poppet valves used in conjunction with a microcontroller can provide closed loop control of hydraulic cylinder pressure or position. Closed loop control of headers on agricultural harvesters enables more sophisticated functionality than present techniques. Floatation (regulating the header's applied ground force) and stubble height (regulating the header's height) are two strategies which can increase crop yield. These allow for more precise tracking of ground contour variations with the header contacting or following above the ground. Machine productivity is increased by consistent and repeatable operation, reduction of operator interaction and automation of header raise and repositioning at the start of each row.

HUSCO's patented CompChek® valve technology provides independent, individual flow compensation in hydraulic directional control valve circuits, while maintaining the specified flow relationships between individual functions, even when total demand exceeds pump output capacity. HUSCO is currently in the process of incorporating this technology into a number of existing product lines, without the addition of complicated components, or changes in envelope size. This paper presents the principles behind this technology, and how they are applied to improve mobile hydraulic machine performance.

Crankshaft angular position measurements are fundamental to all modern automotive engines. These measurements are required to control fuel injection timing as well as ignition timing. However, many other functions can be performed from such measurements through the use of advanced signal processing. These additional functions are essentially diagnostic in nature although there is potential for substitution of primary fuel and ignition control functions. This paper illustrates the application of crankshaft angular position measurement to the estimation of individual cylinder indicated and/or brake torque in IC engines from measurement of crankshaft position/velocity.