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Transient emission peaks have become an important fraction of the total emissions during the standardized test cycles for passenger car Diesel engines. To this end this paper is concerned with the challenge of measuring emissions during transients. The importance of this topic is increasing due to strict regulation on pollutant emissions. Hence, suitably accurate and fast measurement devices for PM emission detection are required. Thus, we present a comparison between different measurement techniques for Particulate matter (PM) emissions from a Diesel engine, in particular during transients. The compared equipments include AVL Micro soot sensor, AVL Opacimeter, Differential mobility spectrometer and Laser induced incandescence. The goal of this paper is to reveal the most accurate device in the sense of sensitivity and dynamics for fast measurements of PM from a Diesel engine.

In a structure, the noise source does not always coincide with the origin of excitation. Vibrational energy is transmitted in the structure and noise is radiated from the surface. For noise and vibration control in beam or shell structures, it is important to clearly identify the excitation sources and vibrational energy transmission characteristics. In this paper, measurement of transient vibrational power flow in a car door excited by impact using the envelope vibration Intensity technique is described. Vibrational power flow caused by flexural vibration in the car door panel is measured with the three channel method. The vibrational power flow is expressed with vibration intensity vectors at each measuring point. Instantaneous distributions of measured vibration intensity vectors in the car door panel are shown in this paper. Temporal and spatial variations of the vibrational power flow are discussed.

Gear rattle is generated basically due to the impacts of unloaded gear pairs in transmission. The rattle noise level is determined by two main factors, excitation level at transmission input shaft and rattle sensitivity of the transmission at that excitation level. In this work, (1) the transmission rattle sensitivity was measured and investigated (2) torsional vibration model of driveline system was developed to estimate the speed fluctuation at the transmission input shaft and to find some rattle improvement potential by tuning driveline components so that the speed fluctuation be minimized.

Tire noise research at the GM Research Laboratories has centered around on-the-road testing with a variable-loading, single-wheel trailer consisting essentially of a truck wheel at the end of a forty foot beam. This approach has proved to be highly satisfactory since it can be used to make realistic tests of the noise from a single truck tire, in isolation from other noise sources and free from interference by echoes from the vehicle structure. Measurement procedures have been developed both for semi-circular arrays of microphones on the ground and microphones and accelerometers traveling with the test tire. For the stationary semi-circular arrays, a digital analysis procedure has been developed to determine the narrow-band spectra and the radiation patterns of the sound emitted by the moving tire as it passes through the center of the semi-circular array.

This paper reviews general methods of identifying noise sources in machinery and in particular it describes in detail two methods which have been studied by the authors on a truck: near field measurements and the coherence technique. The results of these two methods are compared with results of a third method in which the same truck with different sources wrapped and then sequentially exposed was driven past a microphone using the SAE J366b test. The paper also reviews two different stationary indoor standard tests which have been investigated: the reduced drive-by simulation method, and the sound power method. These tests could be used to supplement (or replace) the standard SAE J366b drive-by test in some cases. Comparisons are made of data from the two tests developed and the SAE J366b drive-by data for the same truck.

A number of nuclear power plant steam generators have been troubled with corrosion buildup between the tubes and supporting plates. A vibration type probe which traverses the interior of the tubes during plant shutdown has been developed to inspect the tube and support crevices. The probe incorporates a miniature electric vibrator and accelerometers to induce and measure tube motion at the support plate junctions. Laboratory investigation indicates that clearance gaps ranging from 1 to 30 mils can be accurately and rapidly measured even in the presence of tube misalignment and varied tube support conditions. The probe system is also suited to in-situ measurements of heat exchanger tube vibration characteristics.

This paper presents the experimental analysis for the turbulence in the combustion chamber of a direct injection (D.I.) diesel engine. A dual beam mode, forward-scattering laser doppler velocimeter was applied to the flow measurement in a four-stroke, single-cylinder direct injection diesel engine of 110 mm bore and 125 mm stroke. The turbulence component was separated from instantaneous velocity using a high-pass filter. As a result, the difference in turbulent intensity between the intake and compression processes was discussed. Also, the effect of intake port and piston cavity shapes, the compression ratio and the engine speed on the turbulent intensity were clarified. In addition, the empirical equation for the decay of turbulent intensity in the compression process was expressed by a function of the Reynolds number based on the mean swirling flow.

The paper describes a technique to determine the full 6 by 6 mobility matrix of a point (including rotational degrees of freedom) from measurements. The determination is performed without loading from the excitation equipment (lever, force transducers etc.) and uses only one set-up. The advantages of using only one set-up are that an improved consistency of the mobility matrix is achieved in comparison to traditional techniques, and that it saves set-up time which usually is a large portion of the total time required for the actual measurements. The measurements are performed in two steps. During the first step, the mass- and inertia-loaded mobility matrix is determined by using sequential measurements and a physical model of the excitation equipment. The loaded mobility matrix determined for two structures first a 3-dimensional beam-structure where results are compared to FE-calculations and secondly on a wheel suspension on a car.

Many reports on characterization of unregulated exhaust emissions from diesel engines and its measurement methods have been presented, but the number of objective chemical compositions used in those experiments are limited. Those reports have referred to use of a large and expensive full-flow dilution tunnel specified by US EPA, and also to the fact that, in case of a partial-flow dilution tunnel which is called “mini-tunnel”, the use should be limited only to steady state engine operations. The authors reported in SAE Paper 890181 that a multi-tube type mini-dilution tunnel, which was compact and less expensive, had good agreement with the full-flow dilution tunnel required by US FTP for heavy-duty diesel engines, when the regulated exhaust emissions were measured on a heavy-duty diesel engine under steady state and transient operaton conditions.

The three velocity components and turbulence intensity were measured at the valve curtains around the two inlet valves of a four-valve s.i. engine with a pent-roof chamber. The measurements were made using hotwire anemometry in a steady-flow rig. Data were collected over a wide range of valve lifts and flow rates. The results show that the velocity profiles are strongly dependent on the valve lift and the surrounding geometry but almost insensitive to the flow rate. Flow separations are identified at certain azimuthal locations for large valve lifts. The turbulence intensity varies around the valve peripheries and across the valve gaps, as do the exit angles of the issuing flows. Their profiles are affected by flow separations from the valve seats and faces and by flow interferences between the two inlet valves. These detailed profiles can be used as boundary for multi-dimensional in-cylinder flow models.

Engine valves must operate in engines with very low failure rates. Long-term durability testing is expensive. This cost could be reduced by running only a final successful proof test, provided adequate data existed to demonstrate that potential life and failure modes have been identified and eliminated by short-term tests and analysis. This approach was applied to a 1983 DDA Model 4-53 engine valve. The results are used to estimate valve life and, further, to estimate the effects of tolerance variations on valve life. The techniques used to determine valve temperatures and strains at nominal and unusual operating conditions in firing engines are presented. The experimental study shows that combustion strains and closing strains are caused by two different loading conditions which affect different portions of the valve head, and also shows how these loads vary with their governing parameters. The theoretical basis for these observations and trends is also presented.

Conventional measuring systems are not able to measure the exactly valve timing on real engines. Due to their requirements, the measurement procedure and consequently their accuracy there are variances, which have a great influence on the measurement results. For an improvement of the gas exchange and finally the engine characteristics it is necessary to develop a new way to get the real valve timing on operating engines. Therefore the University of Applied Sciences Hannover developed a new measurement system to detect the exactly valve timing on real operating engines. This method uses the valve and the valve seat ring as an electrical switch, which is reached by an insulation of these parts against each other. The result is that the valve timing, the length of the opening time, valve overlapping and effects like valve bouncing are able to detect by this new measurement system.

The concentration of gasoline vapors was measured in the breathing zone of a person. refueling automobiles in both summer and winter. The concentrations of total hydrocarbons ranged from 5 to 1220 ppmC in summer and from 4 to 3210 ppmC in winter. Individual values were affected by wind speed and direction, as well as by body shielding caused by the refueler. Compared to the dispensed gasoline, the refueling vapors were enriched in hydrocarbons with normal boiling points below about 125°F, so that five light paraffins (n-butane, isopentane, iso-butane, n-pentane, and propane) constituted more than 70% of the total carbon in the vapors. The combination of the resulting low concentration of the heavier hydrocarbons in the vapor and the rapid dispersal and dilution of the vapor plume minimizes the brief exposure of refuelers to benzene and the C7, and C8 isoparaffins.

Global ethanol trade is forecast to increase 25-fold by 2020. Most of it will be blended with gasoline to make biofuel. However, blending ethanol with gasoline has a profound effect on the evaporation characteristics of the mixture. In particular, the thermodynamic properties of the blends can be significantly different than the constituents. A clear understanding of the blend's properties is essential for optimizing engine design, e.g. utilizing charge cooling effect. Data available in the literature is very limited, considering ethanol-gasoline blends will be used as a fuel in large scale worldwide. In this work, comprehensive measurements of vapor pressures were carried out. The enthalpies of vaporization were derived from vapor pressure data using the Clausius-Clapeyron equation. Maximum vapor pressure occurs with 20% ethanol-gasoline blend at which a positive azeotrope is formed. The trend is different in enthalpy of vaporization.

The antenna is an essential part of any audio system. The three quantities that characterize an antenna are gain, impedance, and antenna pattern. The purpose of this paper is to show how the antenna pattern is related to audio system performance and to describe how antenna pattern measurments are performed.

Soft tissue neck injury has become the most frequent type of injury sustained in motor vehicle accidents. Most of these injuries occur in rear-end impacts. Consequently, vehicle head restraint geometry has become an important issue in vehicle design and injury prevention. Vehicle crashworthiness and safety ratings are published by auto insurers around the world including ICBC, the Insurance Corporation of British Columbia (Canada), the Insurance Institute for Highway Safety (U.S.A.) and the New Car Assessment Program (Australia). These vehicle ratings include head restraint ratings based on static measurements of head restraint geometry. The authors developed a device for measuring head restraint geometry used in these ratings, and detail the results of measurements for 40 current vehicles in North America.

The more stringent regulations issued by the brazilian environmental agency CONAMA, regarding the controlling of vehicular noise emissions, indicates the use of the national standard NBR9714. The application of the criteria described in this standard to the normal procedures for fleet control is discussed in this work. Computer simulations are used to analyse the environmental influences to be expected. Actual measurements are done to validate the simulation results. An integrated system to automate the measurements and the report generation is presented.

A Constant Volume Sampler (CVS) compatible auto exhaust particulate sampling system has been built and successfully operated. The system can be used to sample exhaust isokinetically at constant temperature, yields internally consistent results, and can be operated conveniently and frequently. Studies with the sampling system have shown that vehicles equipped with oxidation catalysts convert some of the sulfur in the gasoline to sulfuric acid containing particulates. Bound water was shown to be a major component of the sulfuric acid exhaust particulate. Catalyst type and system design are believed to have a marked effect on the sulfuric acid conversion with additional research required to determine what features result in lower sulfate emissions. Emission tests have shown that platinum emission rates are lower than 2 × 10-5 g/mi. More sensitive analytical techniques will be required to obtain information on a more quantitative basis.

A set of safety-relevant performance qualities for the passenger car has been defined as a first step in the development of objective measures of precrash safety performance. Measures were sought that stress the performance produced by a passenger vehicle when it is operated under emergency crash-avoidance conditions. This goal has led to the identification of six limit maneuvers and associated limit responses to serve as a first-order means of assessing the safety quality of a motor vehicle. The viability and the discriminatory power of the proposed test procedures have been demonstrated by applying these procedures to four separate vehicles.

This study attempts to predict the effect of visual impairment from simulated levels of splash and spray on target vehicle identification distances. Five levels of hand held spray simulation frames were used to compare image digitization methods with visual performance (Snellen acuity or contrast sensitivity) assessment to predict a drivers ability to identify an oncoming target vehicle. The image digitization process was found to be highly correlated with actual target vehicle identification distances. Additionally, very high correlations were found between Snellen acuity and contrast sensitivity and identification distance. There did not seem to be any great difference in predictive power of either method of visual performance assessment over the other.