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This study was conducted to develop an understanding of how rate-shaped and split injections can affect the soot and NOx emissions of a heavy-duty diesel engine. The tests were performed on a single cylinder version of the Caterpillar 3406 production engine, modified to accept an electronically-controlled, high-pressure common-rail injection system that offers a very high degree of flexibility in injection timing, split injections, and rate shaping of the initial injection. The engine was instrumented for particulate measurements with a full dilution tunnel, and CO, CO2 and NOx emission meters. Cylinder pressure was used to study heat release rates, and the response to changes in the injection scheme. The results show that rate-shaped injection, when optimized for lowest BSFC, does not appreciably affect pressure rise or peak cylinder gas pressures.

The complexity of the mixture formation in direct injection engines requires - according to a suitable mixture transportation and vaporization of the fuel - detailed knowledge of the in-cylinder processes to reliably place an ignitable mixture at ignition timing near the spark plug for any speed and load. Two different optical measurement techniques were adapted to a single cylinder engine and the spray propagation was observed from the start of injection until ignition. 3-pentanone tracer-LIF signals (laser-induced fluorescence) and CN spark emission signals were detected simultaneously in order to get information about the local equivalence ratio at the spark plug and compare the two methods. While there is a good correlation for homogeneous operating conditions of the engine, the results diverge in the stratified mode.

Tests were conducted on Diesel engines to determine the cause of exhaust discoloration. Results show that the discoloration occurs for different reasons under different engine conditions (e.g., fully loaded, steady-state operation, full acceleration, etc.). The paper correlates the different discolorations with their respective engine processes. It is concluded that the present Hungarian measurement standard is inadequate. Under the assumption that commercial, city traffic is comparable to personal vehicle traffic, the Europa-Test standard should be adopted whereby the thickness of exhaust effluent is continuously measured. Mechanisms employing light beams and sensors are in development and could be readily installed in the end of the exhaust pipe. Test results would be recorded along with other data such as engine rpm, temperature, etc. Tests can subsequently be done on any appropriate road rather than at test-stands.

The detection of cyclic dispersion, knocking, preignition, misfiring and other phenomena related with abnormal combustion in spark ignition engines has been extensively studied in the past. The transducers most commonly used detect pressure and/or ionization in the combustion chamber. By employing transducers that detect engine head movement it has been possible to examine these phenomena without particular engine modifications, thus enabling measurements to be made in commercial cars. These transducers are used in conjunction with electronic apparatus that gives quantitative measurements of the extent of the abnormal combustion. Results obtained by these means are reported with particular emphasis on high speed knock (a problem presently encountered with European cars), preignition and misfiring. On the basis of the test results a technique is developed utilizing the electron scanning microscope to recognize a posteriori if the piston failure is due to knock or preignition.

The flame on a high injection pressure direct-injection (DI) diesel spray under quiescent conditions stabilizes at a location downstream of the fuel injector. The distance from the injector to the location of stabilization is referred to as the flame “lift-off” length (or height). Air entrained into a diesel spray upstream of the flame lift-off length will mix with the injected fuel. The air and fuel premixed upstream of the lift-off length are believed to react immediately downstream of the location of flame lift-off. Recent measurements suggest that as much as 20% of the air required to burn the fuel injected is entrained prior to the flame lift-off length for typical, moderate-load, heavy-duty DI diesel conditions. These results imply that combustion at the flame lift-off location will play a pivotal role in diesel combustion and emission formation processes.

Knowledge of the forces on the vehicle is necessary for designing most of the Baja vehicle subsystems, however little knowledge of the dynamic forces on small off-road vehicles is available. To measure the vertical and longitudinal forces on the tires of a Baja vehicle, a custom strain gauge system was designed and combined with Quarq tire pressure sensors while running in off-road conditions. The strain gauge system consisted of a half-bridge Wheatstone bridge of 350 Ohm resistors in bending, feeding the change in voltages into the 20-bit ADC of a Cypress Semiconductor PSoC 5LP microcontroller for data interpretation and then recorded onto an SD card for later analysis. Quarq Tyrewiz tire pressure sensors were placed on both the front and rear tires and the recorded pressures were converted to forces on the tire through calibration. Experimental data was found to agree with suspension models.

An engine bench test has been developed to measure the total amount of liquid fuel wetting the intake walls of a S.I. port fuel injected engine under steady-state conditions. A four cylinder engine equipped with a double injection system was been utilized. One injection system was fed with 2-methyl-2-butene, which did not produce liquid fuel deposit on the intake manifold, the other injection system was fed with different types of fuel and both systems were set at the stoichiometric air-fuel ratio. Putting the injection commutation on, the 2-methyl-2-butene is suddenly replaced by the fuel of the second injection system. An oxygen sensor (UEGO type) monitors the air-fuel ratio excursion due to the injection commutation and the test runs until the A/F re-establishment at the stoichiometric level.

For mathematical modeling and analysis of vehicle dynamic performance, a variety of inertial properties are of significance. These include: mass; center of gravity location; yaw, pitch, and roll moments of inertia; and the location of the principal axes of inertia. The large size of most commercial highway vehicles can lead to significant problems in determining, either by computations or by measurements, all of the inertial properties appearing in the mathematical description of a vehicle system. In this paper, new techniques in the measurements of the inertial properties of a cabin of a large commercial highway vehicle are developed and discussed. The specific testing techniques which are employed are extensively described. These measurement techniques are simple and inexpensive, but the resulting information may be of great value to the vehicle dynamics researchers.

Because of its dominant role in diesel engine performance and emissions, the fuel injection process has become an area of very active research and development. It is now clear that location, shape, rate of development, and mass flow distribution within each fuel jet are all important in controlling fuel air mixing, wall interactions, combustion rate, and the resulting levels of emissions. The objective of this project was to develop an instrument for measurement of the instantaneous fuel mass and momentum distribution in the jets issuing from diesel injection nozzles. The goal was to develop an instrument concept that can be used in the laboratory for fundamental measurements, as well as a quality control system for use in manufacture of the injection nozzles. The concept of the instrument is based on the measurement of the instantaneous momentum of the fuel jet as it impacts on a surface equipped with pressure sensitive elements.

The clutch of an F1 car is a key component in the achievement of a successful launch. At this point, the clutch will do more work than at any other time during the race. The clutch can be held slipping for up to 8 seconds, causing considerable heat generation in the friction plates. This paper describes an investigation of the thermal mechanics of the clutch during the launch, and how the heat generated by the period of slipping could affect the frictional properties of the clutch plates. Using a simple single-plate clutch, data from a clutch dynamometer has been accumulated over a range of launch scenarios, including re-starts and short and long slip periods. By analyzing and comparing the data, a wider range of clutch scenarios can be evaluated, including the effects of varying the design parameters of the clutch, along with a more detailed investigation into the effects of banding upon the friction plates.

The phenomenon of autoignition is an important aspect of HCCI and knock, hence reliable information on local gas temperature in a combustion chamber must be obtained. Recently, several studies have been conducted by using laser techniques such as CARS. It has a high spatial resolution, but has proven difficult to apply in the vicinity of combustion chamber wall and requires special measurement skills. Meanwhile, a thermocouple is useful to measure local gas temperature even in the vicinity of wall. However, a traditional one-wire thermocouple is not adaptable to measure the in-cylinder gas temperature due to slow response. The issue of response can be overcome by adopting a two-wire thermocouple. The two-wire thermocouple is consisted of two fine wire thermocouples with different diameter hence it is possible to determine the time constant using the raw data from each thermocouple.

Air quality monitoring of PM10 and associated health studies have focused interest on the size and the number of particles emitted to, and found in, the atmosphere. Automotive sources are one of the important elements in this, and CONCAWE have completed a study of heavy duty diesel particle emissions, complementing their previously reported light duty work. This heavy duty programme, presented here, investigated the nature of particulate emissions from two heavy duty engines (representative of different emissions levels), operating on three marketed fuels, over their respective European legislative heavy duty test cycles. The programme has investigated some of the complexities associated with obtaining credible data (e.g. dilution ratios, system stabilisation time etc.). The number distributions, which were measured over a wide size range (3 to 1000 nm), have been split into two size ranges, representative of nucleation mode and accumulation mode particles.

The number and size distribution of particles emitted from a gasoline direct injection vehicle have been measured over the current European drive cycle and a range of steady state conditions. Measurements were made using the Scanning and Differential Mobility Particle Sizers (SMPS/DMPS) and an Ultrafine Particle Monitor (UPM). During the steady state testing, the number distribution of particles between 7nm-320nm was monitored using the SMPS and the integrated total particle count compared to the UPM measurement. Excellent agreement was seen between the two techniques, except at high speed (120km/h) where the UPM measured a greater number of particles than the SMPS indicating an increase in particles outside the range scanned by the SMPS. During the drive cycles, specific size ranges of particles were monitored using the SMPS/DMPS and the total particle count measured using the UPM. Comparisons between the techniques are also made for Diesel and gasoline vehicles.

Many researchers have reported the measurement of high numbers of emitted particles from gasoline vehicles operating at high speed. To date, in the absence of standard test protocols or analytical techniques, these measurements have all been made from a dilution tunnel set up according to regulatory procedures. Currently, there is great uncertainty relating to the use of the dilution tunnel as a suitable tool for the measurement of automotive particle size and number distribution and also the relevance of the procedure to ambient measurement of the same parameters. Gasoline particle number emissions, as measured on a dilution tunnel, are low at speeds under 120km/h. Beyond this speed, high numbers of very small particles have been measured. There is some evidence to show that these particles may be formed as an artefact within the sampling system, either from the desorption of deposited material or from the pyrolysis of other material in the sampling system itself.

An electrical capacitance measuring method has been used to obtain the cylinder liner oil film thicknesses for various speeds and loads in a heavy duty directly injected diesel engine. Interesting facts have been observed: Increased oil film thickness for the top ring distance to wall during idling. A gas pocket appearing between top ring and liner at increasing speeds and loads movement of the piston in the liner when combustion sets in, the motion is not parallel. temperature seems to have little effect on the oil film thickness. A computer model of the top ring showed good conformance with the measurements over the speed and load range, but the calculated oil film thickness is about 3 to 6 times higher.

Terrestrial winds play an important role in affecting the aerodynamics of road vehicles. Of increasing importance is the effect of the unsteady turbulence structure of these winds and their influence on the process of optimizing aerodynamic performance to reduce fuel consumption. In an effort to predict better the aerodynamic performance of heavy-duty vehicles and various drag reduction technologies, a study was undertaken to measure the turbulent wind characteristics experienced by heavy-duty vehicles on the road. To measure the winds experienced on the road, a sport utility vehicle (SUV) was outfitted with an array of four fast-response pressure probes that could be arranged in vertical or horizontal rake configurations that provided measurements up to 4.0 m from the ground and spanning a width of 2.4 m. To characterize the influence of the proximity of the vehicle on the pressure signals of the probes, the SUV and its measurements system was calibrated in a large wind tunnel.

Dust testing of vehicles on unpaved roads is crucial in the development process for automotive manufacturers. These tests aim to ensure the functionality of locking systems in dusty conditions, minimize dust concentration inside the vehicle, and enhance customer comfort by preventing dust accumulation on the car body. Additionally, deposition on safety-critical parts, such as windshields and sensors, can pose threats to driver vision and autonomous driving capabilities. Currently, dust tests are primarily conducted experimentally at proving grounds. In order to gain early insights and reduce the need for costly physical tests, numerical simulations are becoming a promising alternative. Although simulations of vehicle contamination by dry dust have been studied in the past, they have often lacked detailed models for tire dust resuspension. In addition, few publications address the specifics of dust deposition on vehicles, especially in areas such as door gaps and locks.

The aim of this study was to evaluate the accuracy and precision of measurements of an automatic weighing system used to assess the mass emission of particulate matter emitted by internal combustion engines. Thirty test cycles were carried out for cars equipped with spark-ignition and compression-ignition engines that met the Euro 4, Euro 5 and Euro 6 emission standards. Exhaust gas samples for analysis were taken according to EU 2017/1151 recommendations for driving cycles performed on AVL and Zöllner chassis dynamometers, AVL-CVS i60 LD LE and HORIBA-CVS 7400 S exhaust-gas collection systems, WLTC driving cycle according to EU 2017/1151, NEDC according to UNECE No. 83, RDE, RTS and TFL cycles, non-standard cycles of car manufacturers. The mass emission of particulate matter was measured using Teflon-coated glass filters of Pallflex® Emfab™ type TX40HI20WW, which ranged between 96 ÷ 102 mg.

The determination of a motor vehicle's drag coefficient CD requires measurements of its aerodynamic resistance and its projected frontal area with high measuring accuracies. The presented paper gives an overview of optical methods for measuring projected areas, and describes a newly developed laser reflection system. It operates on a principle similar to that of a light-barrier system but in a reflection mode. With this optical device and a single numerically controlled traversing facility the outer enveloping contour of the vehicle is automatically tracked and the corresponding coordinates are recorded. The principle of the new measuring method, its advantages and results of measurements on test objects and vehicles are discussed in detail.

The accuracy of the injection rate meter based on W. Zeuch's method in the measurement of multiple injection rate and amount was calibrated using a small cam driven piston that is driven by an electric motor. For the pre- or early-injection, a sensor with a high sensitivity can be applied to measure the small pressure increase due to the small injection amount. In case of the multiple injection that has the post and/or late injection, a pressure sensor with a low sensitivity must cover not only the large pressure increase due to the main injection but also the small pressure increase due to the post and/or late injection because the output of the high sensitivity sensor is saturated after the main injection. So the linearity of the low sensitivity pressure sensor was calibrated with the cam driven piston prior to the experiment with the actual injection system.