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Compared with experimental and theoretical approaches modeling of the scavenging process in a two-stroke engine offers great advantages on account of its simplicity and economy. The clear definition of influencing factors and a better physical interpretation of the model laws governing the flow process help to design the model and to determine the test conditions; the model laws also allow the obtained test results to be transferred to the prototype. A relatively simple and inexpensive liquid model presented enables qualitative observations and quantitative evaluations of different port configurations to be made. For the design of port configurations some recommendations are presented. The short circuiting and instabilities in scavenging test results are also mentioned.

Investigations on valve recession of a commercial vehicle engine inlet valve are done. Failure analysis of inlet valve of a six cylinder commercial vehicle engine developing power of 155 BHP is carried out using the software tools IDEAS and TYCON. Failed engine valves are investigated and concluded that the mode of failure of most of them is valve recession, the possible factors responsible for the valve failure are analyzed including the metallurgical properties of the valve. Combustion force, impact force during closure of the valve are the major factors responsible for valve recession. The valve seat angle is considered in the analysis to find if the change in this angle is helpful in increasing the life of the valve. The prevailing wear mechanism has been shown related to the critical operating conditions such as valve closing velocity, combustion load, valve misalignment relative to the seat insert and seat insert material choice.

Use of methanol and ethanol in conventional diesel engines is associated with problems on account of the high self ignition temperature of these fuels. The Hot Surface Ignition (HSI) method wherein a part of the injected fuel is made to touch an electrically heated hot surface for ignition, is an effective way of utilizing these fuels in conventional diesel engines. In the present work two types of HSI engines, one using a large ceramic base and the other using a conventional glowplug were developed. These engines were tested with methanol, M.spirit (about 90 % methanol and 10 % ethanol) and diesel. The results of performance, fuel economy emissions and combustion parameters including heat release rates for these fuels with both the types of HSI engines are presented. Diesel engines are commonly used as primemovers in the mass transportation and agricultural sectors because of their high brake thermal efficiency and reliability.

Nowadays, the technology war always shows the need for rushing hours in the transportation sector. Turbines and IC engines, which generate power, can only be operated with the help of high-pressure air. In this research, an analytical study introduces an innovative boat vehicle driven by air-water interactions. The principles of an OWC (Oscillating Water Column) wave energy converter device is reviewed to find the effects of air-water interactions that are the key concepts for introducing the partially levitated transportation method. The physical conditions around the boat vehicle, such as squat conditions and speed variations, are reviewed under different stream conditions to explore the possibilities of converting the potential energy of water into kinetic energy under dynamic conditions. An experimental Froude - model analysis is presented to find the velocity and kinetic energy at upstream and downstream conditions of the channel.

Current commercial vehicles' engines are complex systems with multiple degrees of freedom. In conjunction with current emissions regulations manufacturers are forced to combine highly developed engines with complex aftertreatment systems. A comprehensive simulation model including the engine and aftertreatment system has been set up in order to study and optimize the overall system. The model uses a phenomenological spray combustion model to predict fuel consumption and NO emissions. In addition physical models for the material temperatures and the reaction kinetics were generated for the aftertreatment system. Steady state and transient measurements were used to calibrate the engine as well as the aftertreatment model. The aim for a system-level optimization was a reduction of fuel consumption while meeting emission standards.

To comply with the upcoming emission regulations for non-road applications, especially the TIER 4 Final emission legislation, a significant reduction in particulate matters and nitrogen oxide emissions is necessary. An exhaust gas after-treatment system with a good performance helps to meet these requirements. The following paper focuses on the possibilities to reduce the nitrogen oxide emissions in exhaust gas after-treatment technology using selective catalytic reduction with AUS32. Using this technology and targeting a nitrogen oxide emission reduction of 90% the exhaust gas after-treatment system enables engine-out emissions of about 3 - 4 g/kWh nitrogen oxide. Considering an increase of only 5% reduction efficiency to 95%, a duplication of engine-out emissions could be acceptable for still meeting TIER 4 Final emission legislation.

This paper will discuss the views and studies that are currently being conducted by the ASTM (American Society for Testing and Materials), D15 Engine Coolants Committee members regarding coolant and cooling system degradation products and their effects. It will include what has been involved in the process of establishing coolant recycling guidelines and several recycling views by heavy-duty manufacturers. This paper will also overview the process of recycling used coolant by a dual-resin, ion-exchange process and indicate how proper maintenance of cooling systems will lower operation costs and eliminate unscheduled downtime. Purification and performance test data will be shown in regards to TDS (Total Dissolved Solids) removal and reinhibition with proper additive levels not requiring the initial SCA (Supplemental Coolant Additive) addition.

For a number of years during cotton harvest in California's San Joaquin Valley, a decrease in cotton plant height was noted in the rows adjacent to the traffic path of the tractor. Studies which measured soil compaction and cotton yields for several tractor configurations were conducted over two growing seasons. The first year's study consisted of sandy and clay test plots with four tractor configurations. The highest yield was with a conventional wheel tractor with dual rear tires and front wheel drive. The plot yielded 27% more cotton in the sandy field and 14% more in the clay field over the least producing tractor plot, which was the belted track tractor. In the second year's study, the highest yield was also with a conventional wheel tractor with dual rear tires and front wheel drive. The plot produced 5% more cotton over the least producing tractor plot, also a belted track tractor. Cotton yields correlated with the soil compaction (cone penetrometer) measurements.

Data link interfaces are a very important part of the heavy duty vehicle industry; sharing information between subsystems is vital. SAE Recommended Practices J1708, J1587 and J1922 were developed to provide standards for proprietary communications, general information sharing, diagnostic definition and early powertrain controls. The industry realized, however, that these standards would not accomplish the ultimate goal-that of a high speed control and communications network. The development of more capable serial data communications for the heavy duty vehicle industry was prompted by the following: the desire of component suppliers to integrate subsystems for improved performance; the advancement of technology; customer expectations; and government regulations.

In the heavy duty vehicle industry, data links allow electronic controllers on a vehicle to interact efficiently to achieve the vehicle's mission. The interactions include sharing sensor data and calculated information, allowing subsystems to influence each other's operation, and communicating subsystem operation state and subsystem configuration. Data links also provide a means for onboard and offboard diagnostic work, including electronic controller identification, reading and clearing diagnostic information, recalibration, and configuration of the controller for the specific vehicle application. The Truck and Bus Control and Communications Network Subcommittee began development of SAE Recommended Practice 51939 to satisfy these needs. This paper presents the serial data communications that have been adopted in the published and draft SAE Truck and Bus J1939 documents: J1939, 51939101, 51939111, 51939121, J1939131, J1939171, J1939173 and J1939181.

Since construction machinery manufacturers recommend various brands and types of greases for their machinery, customers would benefit from a standardized grease which can be used in all construction machinery. Furthermore, construction machinery manufacturers have many experiences of field problems caused by commercially available and commonly used EP Lithium greases. Therefore, the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA) has developed a new grease specification called “Japan Construction Mechanization Association Specification (JCMAS) GK,” for construction equipment. The JCMAS GK includes requirements for National Lubrication and Grease Institute (NLGI) No. 1 and No. 2 consistency grades. The JCMAS GK greases have enough lubricating properties for periodical grease fitting of most construction machines, hydraulic excavators, bulldozers and wheel loaders. The JCMAS GK greases are applicable from -20 to +130 degrees Celsius.

Active Front Steering (AFS) systems have recently been introduced for passenger vehicles to improve handling stability under adverse road conditions. AFS provides a mechanism to augment the steering angle with a small displacement actuator. In this configuration, the steering angle of the front wheels is the combined input of the handwheel with an additional small angle component from an electronically controlled actuator. This paper investigates AFS for large trucks to assist in avoiding jackknife conditions. Emphasis is given to design aspects to minimize the tendency of AFS systems to interfere with the driver's perception of the vehicle responsiveness.

A method to stop jackknifing of all tractor-trailer vehicles by controlling the angle between the tractor and the trailer to a maximum of 15 deg of movement to either side is discussed. Most jackknifing occurs when the driver is forced into a unexpected lane change or into a panic stop to avoid an accident. Tests have proved that when a tractor-trailer is in a 25 deg or more angle, the vehicle is then in an “angle of no return” and a jackknife can occur. When road conditions are unfavorable, due to rain, ice, or snow, the jackknife will be more severe.

Vehicle jackknifing is generally associated with the loss of yaw stability, and is one of the most common cause of serious traffic accidents involving tractor-semitrailer combinations. In this paper, an active braking control strategy is proposed for jackknifing prevention of a tractor-semitrailer combination on a low friction road. The proposed control strategy is realized via upper-level and lower-level control structures considering braking of both the units. In the upper-level control, the required corrective yaw moments for tractor and semitrailer are generated using a PID controller aiming to reduce errors between the actual yaw rates of tractor-semitrailer and the target yaw rates deduced from a reference model. The corrective yaw moments are achieved through brake torque distribution among the tractor and semitrailer axle wheels in the lower-level control.

Advances in vehicle engineering resulted in substantial reduction of the natural retarding capability of trucks and tractor trailers. These trucks need help slowing down; therefore, the market demands improved performance from vehicle retarders. Today's heavy-duty vehicles: Are aerodynamically designed to slip through the air Roll on advanced radial tires GVW or GCW has increased Engines and equipment are more efficient with reduced factional losses. Improved and new Jake Brake® retarding concepts have been developed. In addition to the standard Jake Brake retarders for unit injector and PLN engines, combination of Jake Brake retarders with exhaust brakes and optimized injector cam operated Jake Brake retarder, a new technology high performance Jake Brake retarder for PLN engines has been developed and introduced on the market.

This paper is a discussion on a statistical problem solving approach to determine the root cause of shimmy in a Chrysler Jeep® Cherokee. A blend of statistical approach with strong analytical quantification is used to give the problem solving a non-subjective flavor. The statistical aspect of the problem solving consists of DOE (Design of Experiments) while the analytical portion describes the instrumentation, data acquisition and analysis.

A computer simulation method of assembling parts of a mechanical assembly has been developed by Deere & Company to statistically analyze tolerance stack-up of complex two-dimensional and three-dimensional assemblies. It is called Assembly Variation Simulation System (AVSS). AVSS offers a way to predict the impact of design tolerance and manufacturing variation on assembly quality of a John Deere Crawler Track Chain/Shoe Assembly. This method identified both the amount of variation relative to specifications and the percent contribution of the major contributors to the variation. In addition. AVSS has been used on a variety of other assembly applications. It is a proprietary system presently being marketed.