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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.

Wind noise sources are described including those from the A-pillar region, cavities and bluff bodies. Hydrodynamic pressure fluctuations results from flow separations (in such areas as the A-pillars and mirrors) that generate relatively broad band in-cabin noise. The influence on local radii of the A-pillar is outlined and shown to be a dominant factor in determining hydrodynamic pressure fluctuations in the side-glass regions. Small cavities (eg. styling or water management channels on the mirror casing) generate high-frequency acoustic tones that can also be heard in the cabin and an example of tones from a whistling mirror cavity is shown. A spectrogram of in-cabin noise obtained whilst driving in strong winds is used to illustrate the variability of noise that can be heard on-road and to consider the influence of the relative wind speed.

Using a three-degree-of-freedom vehicle model (side-slip, yaw and roll degrees of freedom) and a nonlinear, saturating rire model, the behavior of a typical exemplar vehicle (1986 Dodge Lancer Turbo) was simulated. Steady state performance was examined through simulating a skidpad lateral accelerarion maneuver. A lane change maneuver was used to reprcsenr transient performance characteristics. A few simple experiments were conducted wirh rhe exemplar vehicle to establish parameters and verify some performance properties. Results of both steady srare and rransienr simulations showed that four -wheel steer offers lirrle or no demonstrated performance advanrages over two-wheel steer.

Transient and steady-state analyses of electrically heated, Thermionic Fuel Elements (TFEs) for Topaz-II space power system were performed. The calculated emitter and collector temperatures, load electric power and conversion efficiency were in good agreement with reported data. The effects of Cs pressure, thermal power input, and load resistance on the steady-state performance of the TFE were also investigated. In addition, the thermal response of the ZrH moderator during a startup transient and following a change in the thermal power input was examined.

Nowadays, the design of radiator of hydraulic system is based on the equilibrium temperature, i.e. under that temperature the heat energy generated by system is equal to the heat energy dissipated. When the working time is not long, the oil temperature can't reach the equilibrium temperature. If the design is still based on the equilibrium temperature, the designed radiator will be larger than needed. This paper studies the temperature rising transient of hydraulic system and suggests a new method of radiator design, which can rationally determine the dissipating area of radiator. This method have been used in the radiator design of a hydraulic crane and get a satisfied result.

This paper deals with the transient response of a highly turbocharged gasoline engine. This downsized engine should behave as a naturally aspirated engine when the throttle is suddenly opened. However, a turbo lag occurs and this phenomenon is of large importance for the vehicle acceleration and driver sensations. To reduce turbo lag effects, an electrical compressor (E-booster) was used to improve the main compressor and engine responses. The study was led on a three cylinder 1L turbo-charged engine. 1-D simulations (WAVE code) with a MATLAB-SIMULINK coupling were used to calculate the engine and vehicle transient responses. The vehicle, turbocharger and E-booster characteristics were simulated by the model. Second to third gear wide open throttle accelerations, varying engine loads at constant speed were also simulated. The calculations give important results like E-booster electrical consumption, and focus on the most significant parameters.

The NO reduction in an ammonia SCR converter has been simulated by a 1D+1D model for a single representative channel to parametrically study the characteristics of the system under typical operating conditions. An appropriate model has been selected interpreting the chemical behavior of the system and the parameters are calibrated based on a comprehensive set of experiments with an Fe-Zeolite washcoated monolith for different feed concentrations, temperatures and flow rates. Physical and chemical properties are determined as well as kinetics and rate parameters and the model has been verified by experimental data at different operating conditions. Three different mechanisms for the surface kinetics to model NO reduction have been assessed and the results have been compared in the cases of steady DeNO performance and transient response of the system. Ammonia inhibition is considered in the model since it has a major effect specifically under transient operating conditions.

In 1995, the United States Environmental Protection Agency published the first phase of regulation for utility engines defined as certain new non-road spark ignited engines that have a gross power output at and below 19 kW. The first phase was adapted from the existing California Tier I Regulation with the understanding that the second phase of EPA regulation would be a thorough review of the first phase. This paper reports the results of the test procedure evaluation pertaining to this second phase of regulation. The information includes field evaluation of the equipment for in-use operating characteristics, application of known steady state emissions tests procedures and new transient procedures, and a comparison of the results.

Water wading tests are commonly performed for vehicles to ensure the functional integrity of different under-hood components at different water depths. This test has its relevance in both conventional Internal Combustion (IC) engine-based vehicles and Electric Vehicles (EVs). In IC engines, it is important for designing the Air Induction System (AIS), and for EVs, it helps to check the wetting of critical electrical and electronic components. The experimental setup for this test includes a long water tunnel where the car enters and exits the pool of water through a ramp. This work is an extension of the work done by Varshney et al. [6] where the Moving Reference Frame (MRF) technique was used to account for the motion of the car and the rotation of the wheels. The current work uses mesh morphing techniques to account for the motion of the vehicle and the rotation of the wheels that replicates the actual test conditions, including the inclination of the vehicle on the ramp.

This paper reports on a comprehensive, crank-angle transient, three dimensional, computational fluid dynamics (CFD) model of the complete lubrication system of a multi-cylinder engine using the CFD software Simerics-Sys / PumpLinx. This work represents an advance in system-level modeling of the engine lubrication system over the current state of the art of one-dimensional models. The model was applied to a 16 cylinder, reciprocating internal combustion engine lubrication system. The computational domain includes the positive displacement gear pump, the pressure regulation valve, bearings, piston pins, piston cooling jets, the oil cooler, the oil filter etc… The motion of the regulation valve was predicted by strongly coupling a rigorous force balance on the valve to the flow.

Analysis of performance data for complex mechanical energy conversion and control equipment has shown that human learning is a contributing factor to reliability growth. Resolution of technical problems is delayed until the personnel involved have developed the skills enabling them to effectively do their jobs. Added to the effect of wrong decisions and inadequately performed tasks is the accompanying lack of self-confidence that may result in the failure of personnel to assume responsibility for their actions. Case histories are presented to illustrate some of the situations that cause set-backs in reliability growth, with emphasis on that part caused by the learning process.

Electromagnetic actuators for electromechanical valve trains are highly nonlinear devices. The understanding and knowledge of their dynamics are essential for a proper use in such application. In this paper, a simple, yet comprehensive model is used to examine the effect of eddy currents on system dynamics. Furthermore, a voltage driven finite element model is established, which implements the nonlinear magnetic material properties with a modified Weibull distribution. Switch-off experiments with an electromagnetic actuator are carried out and the results are compared with the finite element simulations.

Two wheeler 4-stroke small Engine with Kick Start requires longer spark duration along with better spark energy in order to burn the lean mixture and to have better Start ability, lower trigger start RPM is also important to enable ease of start. An effective Ignition System needs to be designed for the above purpose. Hence Transistor Controlled Ignition/Inductive Discharge System (TCI/IDI) unit is preferred which gives all the above mentioned requirements. Normally any conventional TCI/IDI operated 4-stroke two wheelers will have D.C power line align with a Power Source for its operation. The 2 Wheeler Kick start version cannot afford the DC Power Source due to Cost, Hence the Electrical System will not have the DC Power Line. So it is not possible to operate a Conventional TCI/IDI system as it is DC Power based System. The challenge is to operate the TCI/IDI ignition unit without DC Power Source i.e. using AC Source.

THE TRANSISTOR SWITCHED ignition system may replace induction coil for applications where a premium can be paid for reliability. This paper describes the design features and advantages of this system, along with applications. The new system can be used interchangeably with the present conventional induction coil. Using a slow coil (high-tension transformer) the system features: 1. Voltage output which is relatively flat throughout the engine speed range. 2. Reduced contact current giving unlimited electrical life and reliability of contacts. 3. Performance under fouling conditions at least equal to the present induction coil. 4. Voltage ceiling flexibility — the voltage can be raised to provide for possible future engine designs.*

The high-speed performance of the conventional multi-cylinder coil ignition system is limited by the reduced contact dwell times with increasing speed, and by the mechanical limitations of cam operated contact breakers. The introduction of semiconductor devices, and their continued development, has enabled a racing eight-cylinder contactless ignition system to be produced, capable of providing ignition for engine speeds up to 15,000 rpm. This system is described, along with a transistor assisted contacts system and a contactless system for conventional vehicles.

The Federal Transit Administration is leading the effort to design, develop, and deploy Intelligent Vehicle Initiative (IVI) technologies on the transit bus vehicle platform. By, providing a method for quickly analyzing technologies and testing prototype systems, the FTA has shown a process for deploying advanced technologies on transit buses. This paper sets the stage for IVI development, and points out the differences in the transit vehicle platform as opposed to the light vehicle and commercial vehicle platforms. In addition, the paper highlights the advanced technology programs that FTA offers, and will use to bring IVI technologies to full-time operating service.

A typical production transit bus with vertical pillars of small section size, low gauge and low strength steel, exhibits extensive lateral pillar side-sway collapse (matchboxing) in rollover impacts. This matchboxing allows rollover of the bus onto its roof. LS-DYNA simulations demonstrate that roof pillars of high strength steel or inexpensive E-glass fiber reinforced polymer (FRP) pultrusions can prevent matchboxing and arrest the rollover of the bus. However, for the same space envelope, pultruded FRP pillars can be at least 41% lighter than high strength steel square tubes exhibiting the same bending moment capacity.

A new method of comparing the fuel economy of transit buses has been demonstrated. The method is based on SAE J1321 (1)*. The SAE test procedure was combined with the Transit Coach Design Operating Profile Duty Cycle from the “White Book” (2) and the test track configuration to produce MPG data for the commuter, arterial, and central business district phases of the duty cycle and MPG data for the combined or overall test cycle. The resulting test procedure makes possible the determination of MPG on a wide range of revenue duty cycles and could be useful in calculating life-cycle cost of transit buses. The six 40-foot buses used in this series of tests were produced by six different manufacturers and featured different drive configurations, curb weights, and seating capacities.

A transit bus fuel economy testing procedure has been developed, and verified by proving grounds tests, that will enable the motor coach industry to accurately evaluate vehicle modifications and new components without arduous and lengthy revenue service operations. This procedure is based on the proposed Society of Automotive Engineers (SAE) recommended practice for Type II fuel economy testing of heavy-duty vehicles. Verification of the procedure was done by obtaining repeatable results from testing of bus weights and diesel fuels. Tests of other variables produced the following fuel consumption results. Changes in the bus weights produced a reduction of one half the percentage of each weight loss. Diesel fuel #2 demonstrated a one percent improvement over diesel #1, measured on a volume basis. Turbocharged diesel engines demonstrated at least a 7 percent improvement over the baseline engine.

This report presents the results of bus simulation studies which determined the effects of various design and operating parameters on bus fuel economy and performance. The bus components are first described in terms of how they are modeled. Then a variation of each component is performed and the resulting fuel economy and performance are presented as sensitivities and tradeoffs. Relative fuel consumption estimated by the HEVSIM Simulation Program and measured in track tests was shown to compare within ± 1 percent in six of nine cases. Explanations are offered in cases where the variation was slightly greater than the ± 1 percent band allowed by the SAE Type II J1321 test procedures.