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In this paper, a High-Temperature Electrical Low-Pressure Impactor (HT-ELPI+) was used to measure particles from a light-duty direct injected spark ignited (DISI) engine fueled with gasoline and ethanol. The HT-ELPI+ measured volatile and non-volatile particle emissions down to 6 nm without the need for dilution. Particle emissions were measured at four operating points while sweeping the end of injection, and at idle operation. The total particle number (PN) and particle size distribution (number and mass) for both non-volatile and volatile emissions were measured with the HT-ELPI+ and compared to the measured PN using two 71.4 times diluted Condensation Particle Counters (CPCs) with two different cut-off sizes, with 23 nm and 7 nm cut-off, respectively. The results show an increase in particle emissions in terms of particle mass and total particle number for ethanol compared to gasoline. The difference in soot mass emissions is small between the fuels.

Thermal Barrier Coatings (TBCs) may be used on the inner surfaces of exhaust manifolds in heavy-duty diesel engines to improve the fuel efficiency and prolong the life of the component. The coatings need to have a long thermal cyclic life and also be able to reduce the temperature in the substrate material. A lower temperature of the substrate material reduces the oxidation rate and has a positive influence on the thermo-mechanical fatigue life. A test rig for evaluating these properties for several different coatings simultaneously in the correct environment was developed and tested for two different TBCs and one oxidation-resistant coating. Exhausts were redirected from a diesel engine and led through a series of coated pipes. These pipes were thermally cycled by alternating the temperature of the exhausts. Initial damage in the form of cracks within the top coats of the TBCs was found after cycling 150 times between 50°C and 530°C.

The emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles were obtained by a fast mobility particle sizer and an optical particle sizer. The temperature was measured by a thermocouple installed in the disc. The experiments show that as the temperature increases from 100 to 300 °C the emission of ultrafine particles intensifies while that of coarse particles decreases. There is a critical temperature at which the ultrafine particle emission rate rises stepwise by 4 to 6 orders of magnitude. For the friction pairs investigated, the critical temperature was found to be between 165 and 190 °C.

The drive to reduce particle emissions from heavy-duty diesel engines has reached the stage where the contribution from the lubricant can have a major impact on the total amount of particulate matter (PM). This paper proposes a model to predict the survival rate (unburnt oil divided by oil consumption) of the hydrocarbons from the lubricant consumed in the cylinder. The input data are oil consumption and cylinder temperature versus crank angle. The proposed model was tuned to correlate well with data from a six-cylinder heavy-duty diesel engine that meets the Euro 5 legislation without exhaust gas aftertreatment. The measured (and modelled) oil survival shows a strong correlation with engine power. The maximum oil survival rate measured (19%) was at motoring conditions at high speed. For this engine, loads above 100 kW yielded an oil survival rate of nearly zero.

During braking, both the rotor and the pads are worn in disc brakes. This wear process generates particles which may become airborne. In passenger car field tests it is difficult to distinguish these particles from others in the surrounding environment. It may therefore be preferable to use laboratory test stands and/or simulation models to study the amount of airborne wear particles generated. This paper discusses the possibility of predicting the number distribution of airborne wear particles generated from the pad to rotor contact in disc brakes by using general purpose finite element software. A simulation methodology is proposed where the particle coefficient is established by testing at material level. This coefficient is then used in numerical wear simulation at component level. The simulated number distribution is compared to experimental measurements at component level.

One-dimensional engine simulation codes are frequently used for engine development where turbine performance is in focus for overall engine performance. Turbocharger performance can today not be accurately simulated without adjustments of the turbine efficiency and mass flow multipliers. In spite of the fact that engine exhausts are dominated by unsteady pulsating flow the performance maps provided by the turbo manufacturers are measured under steady conditions and for a range that does not cover the entire turbine operating range. The scope of this investigation is to calculate instantaneous on-engine turbine efficiency from measured and simulated engine data. These calculations are performed as a step towards generating turbine performance maps that will allow predictive engine simulations with higher accuracy than today. Results show an asymmetric behaviour of the twin-entry turbine.

PCI combustion of diesel fuel was accomplished in a direct-injected heavy-duty single-cylinder research engine. An impinging spray nozzle combined with a shallow bowl piston design offered a short air/fuel mixing time. Low HC and CO emissions were observed compared to fully premixed operation using n-heptane. A method for evaluating the air/fuel mixing process has been established by quantifying the in-cylinder air/fuel heterogeneity with the NOx emission. The results indicate that high injection pressure and engine speed are favorable for a fast mixing process. The injection pressure had a small impact on HC and CO emissions, while the engine speed had a larger impact. There were no correlation between air/fuel mixing time and HC and CO emissions.