Search Results

The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken.

The potential contributions of acoustical technology to manufacturing companies pervade nearly all of its functions from marketing and product planning to design engineering and quality control. Despite this, however, companies generally feel uneasy when they embark on programs to use acoustics in their operations because the technology seems complicated and somehow harder to “get a handle on” than it is in other cases. But the issues of product sound, and the benefits of acoustics on a diagnostic tool are too important to ignore, so in this paper we discuss these issues in a “20 questions” format to help planners, engineers and managers as they proceed to implement acoustical technology in their organizations.

Abstract Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in order to adapt to the requirements of internal combustion engines. An understanding of the working mechanisms as well as an understanding of the way that losses occur in the flow allows a reduced development effort during the optimization process. This article presents three-dimensional (3D) Computational Fluid Dynamics (CFD) investigations of the loss mechanisms and quantitative calculations of individual losses. The 3D-CFD method used in this article will reduce the drawbacks of one-dimensional calculation as far as possible. For example, the twist of the blades is taken into account and the “discrete” method is used for loss calculation instead of the “average” method.

Abstract Regulations limiting GreenHouse Gases (GHG) from Heavy-Duty (HD) commercial vehicles in the United States (US) and European Union will phase in between the 2024 and 2030 model years. These mandates require efficiency improvements at both the engine and vehicle levels, with the most stringent reductions required in the heaviest vehicles used for long-haul applications. At the same time, a 90% reduction in oxides of nitrogen (NOx) will be required as part of new regulations from the California Air Resources Board. Any technologies applied to improve engine efficiency must therefore not come at the expense of increased NOx emissions. Research into advanced engine architectures and components has identified improved turbomachine efficiency as one of the largest potential contributors to engine efficiency improvement. However this comes at the cost of a reduced capability to drive high-pressure Exhaust Gas Recirculation (EGR).

By means of computer simulation, the potential of a Band Variable-Inertia Flywheel (BVIF) as an energy storage device for a diesel engine city bus is evaluated. Replacing both a fixed-inertia flywheel (FIF) and a continuously variable transmission (CVT), the BVIF is capable of accelerating a vehicle from rest to a nearly-constant speed, while recovering part of the kinetic energy normally dissipated through braking of the vehicle. The results are compared with that of conventionally-powered bus. A fuel saving of up to 30 percent is shown with the BVIF-integrated system. The regenerative braking system reduces brake wear by a factor of five in comparison with the conventional vehicle.

Parameters like brake mean effective pressure, mean velocity of the piston, hardness of the wear surface, oil film thickness, and surface areas of critical wear parts are similar for all the diesel engines. The mean piston velocity at the rated speed is nearly the same for all the diesel engines. The mechanical efficiency normalized to an arbitrary brake mean effective pressure (bmep) is dependent on the size of the engine. The engine life seems to be proportional directly to the square of a characteristic dimension namely, cylinder bore of the engine and inversely to speed and load factor for engines varying widely in sizes and ratings.

Current trends in application technology indicate an increasing realization on the part of manufacturers and users of agricultural chemicals of the important role that application techniques and/or equipment play in the overall success of pesticide application. The trends that are most significantly influencing the way chemicals are currently applied include: increased emphasis on improving the accuracy of application increased use of low volume application (3-8 GPA) renewed interest in use of granular application increased use of conservation tillage increased emphasis on reduction in environmental contamination, both within and outside the target area increased use of highly active cam-pounds

Close-range photogrammetry (CRP) is traditionally based on a network captured with the camera lens at a fixed focal length. A zoom lens is not desirable without solving the intrinsic camera parameters for varying focal length and lens distortion. When using a zoom lens camera, multiple focal lengths can be used if the camera is calibrated for each varying focal length, but most consumer grade lenses are not designed to accurately return to (or stay at) mid-range focal lengths. Similarly, using close-range photogrammetric software systems to accurately recover three-dimensional (XYZ) data from Point and Shoot (PAS) digital cameras has been problematic when the images were not intended for CRP. PAS cameras are automatically refocused and easily zoomed so the focal length and lens distortion are typically unknown for CRP mensuration purposes. In such circumstances, traditional CRP analysis can be both laborious and difficult without the correct camera parameters.

A quasi-dimensional computer simulation model is presented to simulate the thermodynamic and chemical processes occurring within a spark ignition engine during compression, combustion and expansion based upon the laws of thermodynamics and the theory of equilibrium. A two-zone combustion model, with a spherically expanding flame front originating from the spark location, is applied. The flame speed is calculated by the application of a turbulent entrainment propagation model. A simplified theory for the prediction of in-cylinder charge motion is proposed which calculates the mean turbulence intensity and scale at any time during the closed cycle. It is then used to describe both heat transfer and turbulent flame propagation. The model has been designed specifically for the two-stroke cycle engine and facilitates seven of the most common combustion chamber geometries. The fundamental theory is nevertheless applicable to any four-stroke cycle engine.

Frequency domain testing has had limited use in the past for durability evaluations of automotive components. Recent advances and new perspectives now make it a viable option. Using frequency domain testing for components, test times can be greatly reduced, resulting in considerable savings of time, money, and resources. Quality can be built into the component, thus making real-time subsystem and full vehicle testing and development more meaningful. Time domain testing historically started with block cycle histogram tests. Improved capabilities of computers, controllers, math procedures, and algorithms have led to real time simulation in the laboratory. Real time simulation is a time domain technique for duplicating real world environments using computer controlled multi-axial load inputs. It contains all phase information as in the recorded proving ground data. However, normal equipment limitations prevent the operation at higher frequencies.

Regulatory requirements in the European Union (EU) for off-road machines and road vehicles are different. Vehicles which transport passengers and goods, along with attached trailers, as well as road motorcycles must meet EEC type-approval requirements. All other types of self-propelled machines must meet the requirements of the Machinery Directive (Council Directive 98/37/EC), and the Electromagnetic Compatibility (EMC) Directive (Council Directive 89/336/EEC) and possibly other directives. This includes such categories as agriculture and forestry machines, construction machines, industrial trucks and similar products. The various directives outline the different processes for demonstrating compliance with the EU requirements. The intent of this paper is to summarize a few of the requirements that are of interest to off-highway equipment manufacturers and to identify some sources of information about the regulatory requirements.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms a good strategy will be to optimize the engine out emission through in cylinder emission control techniques and a right sized after treatment system has to be used for this optimized engine. There exist several factors and trade-off between these should be established for in cylinder optimization of emissions. Since the turbocharger plays an apex role in controlling both the performance and engine out emissions of a CI engine, turbocharger selection is a crucial step in the development of new generation of Euro 6 engines in India. Such engines are equipped with additional actuators such as Intake Throttle Valve and Exhaust Throttle Valve and combination of these flap operations with turbocharger output plays a prominent role in controlling performance and emission.

Effects of included spray angle with different injection strategies on combustion characteristics, performance and amount of pollutant emission have been computationally investigated in a common rail heavy-duty DI diesel engine. The CFD model was firstly validated with experimental data achieved from a Caterpillar 3401 diesel engine for a conventional part load condition at 1600 rev/min. Three different included spray angles (α = 145°, 105°, 90°) were studied in comparison with the traditional spray injection angle (α = 125°). The results show that spray targeting is very effective for controlling the in-cylinder mixture distributions especially when it accompanied with various injection strategies. It was found that 105° spray cone angle along with an optimized split pre- and post-Top Dead Center (TDC) injection strategy could significantly reduce NOx and soot emissions without much penalty of the fuel consumption, as compared to the wide spray angle.

This paper describes the simulation model of a backhoe excavator. The model uses a prescribed motion cycle and the objective of the program is to determine the power requirements for each of the cylinders as well as the total engine power requirement. Most computer simulations are developed by expressing the differential equations of motion for the system being studied. The known force inputs to the system are applied and the time response of the system is then obtained by numerically integrating the governing differential equations. This paper on the other hand develops the reverse of this. Utilizing a prescribed geometry and trajectory cycle for a linkage system as the input, the program solves for the types of force inputs that are required to achieve that trajectory. With the time dependence of the trajectory known, the total power required and the power required of each cylinder is also evaluated. A typical excavator linkage is shown in Fig. 1.

Water-cooled charge air cooling is being considered as part of various technology solutions in response to 2007 US, 2010 US, EU4 and EU5 emissions standards. As manufacturers determine appropriate engine and vehicle solutions to meet the upcoming emissions standards, charge air cooling requirements are increasing due to higher turbocharger outlet temperatures and pressures, higher EGR rates, and requests for intake manifold temperature control to manage combustion and exhaust temperatures. Valeo and EMP have collaborated on the development and testing of a water cooled charge air cooler (WCCAC), controlled by a 12 volt brushless motor coolant pump. The system design addresses material temperature limitations of air-air aluminum CAC's and has the potential to simplify the packaging of the air induction system.

A software tool has been developed to aid designers and process engineers in the development and improvement of heat treat processes. This tool, DANTE™, combines metallurgical phase transformation models with mass diffusion, thermal and mechanical models to simulate the heating, carburization, quenching and tempering of steel parts. The technology behind the DANTE software and some applications are presented in this paper.

On January 10th, 1972, an S. A. E. Paper “Lighting System Performance and the Computer as a Maintenance Tool” (720087) was presented by Charles J. Owen. This was a paper presented on the causes, effects, corrections and a study in good and bad electrical wiring, presented pictorially as well as editorially. We recommend that paper to you for reading. On November 4th, 1974, S. A. E. Paper “A Case for Standardization” (741143) was presented by Charles J. Owen. The purpose of this paper was intent on “improving the breed”. The recommendations and specifications were very specific. In view of the two previous papers, this paper is presented specifically for the designer with back-up data involving recommendations that the industry have generally accepted as applied to the electrical wiring systems The practical data included, is a first in relating indexes of performance and indexes to cost comparisons. The usefulness of this paper in aiding a Designer is the target of the authors.

The absence of combustion information continues to be one of the key obstacles to the intelligent development of engines. Currently, the cost of integrating cylinder pressure sensors remains too high, prompting attention to methods for extracting combustion information from existing sensing data. Mean-value combustion models for engines are unable to capture changes of combustion parameters. Furthermore, the methods of reconstructing combustion information using sensor signals mainly depend on the working state of the sensors, and the reliability of reconstructed values is directly influenced by sensor malfunctions. Due to the concentration of operating conditions of hybrid vehicles, the reliability of priori calibration map has increased. Therefore, a combustion information reconstruction method based on priori calibration information and the fused feature deviations of existing sensing signals is proposed and named the "Deviation-based Centroid Displacement Method" (DCDM).

Diesel powered vehicles are characterized by two distinctives, of particulate, sensed by sight, and odor, sensed by smell. Dramatically reducing these distinctives would result in a “clean diesel”. A joint program of Yellow Freight System, Inc. (YFS) and the author's employer (DCI) has addressed one distinctive (particulate) and has resulted in an exhaust filtering system for the diesel forklift trucks YFS use to move freight at their terminals. This paper covers design, installation, and testing of the system to filter the particulate emissions emanating from these forklifts. The filters, designed to operate for one programmed maintenance (PM) cycle, are then cleaned in off-board equipment and returned to service for another cycle. All filter materials utilized are compatible with the 200°C normal maximum operating temperature, although short excursions to 260°C have not been detrimental.