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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.

The infrared technology for ACC sensors has reached a high standard up til now, but there are still problems with the detection of some vehicles. The most important factors for low detection ranges are bad weather conditions and the state of the vehicle. In order to guarantee a reliable function of the sensor it's important to know about the reflection properties of the vehicles. In this diploma work the influence of different factors on the reflection properties of vehicles was investigated. The parameters, which were taken into regard, are the colour of vehicles, the geometry of the vehicle rear, the viewing angle and the contamination of vehicles. The measurements were made with a modified LEICA ODIN 3 sensor with a very small aperture of the laser beam. This modified sensor was mounted in two axes rotatable, that the rear of the cars could be scanned, to measure the reflected radiation in every point of the rear.

Capacitance film thickness transducers have been developed which, when fitted into the cylinder liner of a diesel engine, enable the operating profile of the piston ring and the ring to liner oil film thickness to be obtained. The construction and operation of the gauges are described and some measurements are presented from the mid-stroke and top-dead-centre positions in a Caterpillar 1-G oil test engine.

This paper presents a method of measuring rolling element loads within large size ball bearings of four-point contact configuration. The rolling element loads are measured with an original method under five fastened conditions for a turntable bearing. The rolling element load distribution is obtained, and the results are compared to the computed loads and distributions.

In rear wheel drive vehicles, passenger perceived tonal noise is often generated by high frequency rotational vibrations of the transmission output shaft. This rotational vibration is excited by the transmission and couples with the dynamic and inertial properties of the driveline and suspension to generate forces through the suspension attachment locations. This paper demonstrates an approach which uses experimental techniques to measure the rotational dynamics of the output shaft and noise path analysis procedures to predict the vehicle system interaction and resulting vehicle noise contribution from this path. An evaluation of three rotational data acquisition techniques, a measurement technique used to characterize a vehicle's torsional acoustic sensitivity, and an application of mobility coupling to the torsional noise path is presented.

Precision spherical joints are widely employed in parallel mechanisms, but its rotation orientation and angle can not be known in its passive motion. Measurement of multi-dimensional angular displacement will be very of great significance in the prediction, feedback and control of motion errors of parallel mechanism. Based on the magnetic effect, a new method to identify the orientation and rotation angle with Hall sensors array matched by permanent magnet is proposed. The basic idea is embedding a permanent magnet(PM) in the ball head and several hall sensors are distributed in the ball socket. When the ball head carrying the permanent magnet rotates together, the Hall sensors array will detect the variation of magnetic induction intensity, and then the angle can be calculated by mathematics model.

Two structure-borne and two airborne paths were measured on 99 “identical” Isuzu RODEOs and 57 “identical” Isuzu pickup trucks. Significant effort was made to control measurement variability but not environmental (climate) variations. A record was kept of the tests of a reference vehicle over the variation of environmental factors. The frequency response functions (FRFs) of the reference vehicle varied by approximately 2-4 dB over the frequency range 0-500 Hz for the structure-borne paths and over 0-1000 Hz for the airborne paths due to measurement and environmental variations. The FRFs of the fleet varied by as much as 5-10 dB over the same frequency range. In this paper, the vehicle tests are described. The reference and the fleet data are shown in raw form. Reduced data and implications of the results are also discussed.

The two-load method is used to measure the transmission loss of thin panels in two different sized impedance tubes (3.49 cm and 10.16 cm). Samples were initially tested with a clamped boundary condition. This was followed by tests with an elastomer inserted between the tube and tested sample to adjust the boundary condition at the periphery. In all tests performed, the influence of the sample holding method could not be removed from the test. The measured transmission loss was compared to finite element simulation with good agreement for both impedance tubes. Additionally, the effect of a compliant boundary condition along the periphery of the sample was also validated via simulation.

A novel method of measuring cylinder gas temperature in an internal combustion engine cylinder is introduced. The physical basis for the technique is that the flow rate through an orifice is a function of the temperature of the gas flowing through the orifice. Using a pressure transducer in the cylinder, and another in a chamber connected to the cylinder via an orifice, it is shown how the cylinder temperature can be determined with useful sensitivity. In this paper the governing equations are derived, which show that the heat transfer characteristics of the chamber are critical to the performance of the system, and that isothermal or adiabatic conditions give the optimum performance. For a typical internal combustion engine, it is found that the pre-compression cylinder temperature is related to the chamber pressure late in the compression process with sensitivity of the order of 0.005 bar/K.

Conventional laboratory viscometric methods are not adequate to characterise the behaviour of multigrade oils in service, in that they take no account of the high shear rates occurring in running engines. A technique has been developed which permits the measurement of apparent viscosity in the crankshaft bearings of engines running under road conditions. The technique is to isolate a single bearing, provide it with its own oil feed and calibrate flow-rates through it under normal running conditions using single grade oils. Flow rates obtained with multigrade oils can then be converted to apparent viscosities, seen by the bearing under operating conditions. Results show that temporary viscosity loss due to shear is important even at moderate speeds (3000 rpm) in normal production engines. Shear breakdown characteristics of a range of different chemical types of VI Improvers have been compared.

This paper describes the development of a thin film rheometer able to measure the viscosity of lubricant films of the order of 200 μm thickness on flat, solid surfaces. The rheometer consists of a small cylinder mounted on a piezo bimorph which is divided electrically into two halves. When an AC voltage is applied to the one half of the piezo it causes the flat surface of the cylinder to oscillate in its own plane with an amplitude of a few microns. This motion produces an AC output from the other half of the piezo. The flat face of the cylinder is held parallel to an oily test surface and the latter is supported on a micrometer stage so that the gap between the two surfaces can be adjusted. As the gap is narrowed the oil film dampens the sinusoidal motion of the cylinder and the extent of this damping can be used to determine the viscosity of the oil film between the surfaces.

In this paper the fuel path of a sequentially injected gasoline engine is discussed. Since a fraction of the injected fuel suffers a delay due to the wall-wetting phenomenon, in transient phases a significant deviation of the air-to-fuel ratio from its setpoint can arise. The amount of fuel on the manifold wall and its rate of evaporation cannot be measured directly. Therefore, the effects of the wall-wetting on exhaust lambda and engine torque have to be considered for the identification of the dynamics. The dynamics of the exhaust-gas-oxygen (EGO) sensor is not negligible for the interpretation of the lambda measurement. Since both the dynamics and the statics of a ZrO2 Sensor are very nonlinear, a normal EGO-sensor is not suitable for these investigations. On the other hand, the engine torque is a good measure for the cylinder lambda when all other effects which lead to torque changes can be eliminated.