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Ethanol fuel blends with gasoline for spark ignition (SI) internal combustion engines are widely used on account of their advantages in terms of fuel economy and emissions reduction potential. The focus of this paper is to study the effects of these blends on combustion characteristics such as in-cylinder pressure profiles, gas-phase emissions (e.g., unburned hydrocarbons, NOx) and particulates (e.g., particulate matter and particle number) using both measurement campaigns and digital engineering workflows. Nineteen load-speed operating points in a 1L 3-cylinder GDI SI engine were measured and modelled. The measurements for in-cylinder pressure and emissions were repeated at each operating point for three types of fuel: gasoline (E0, 0% by volume of ethanol blend), E10 (10 % by volume of ethanol blend) and E20 (20% by volume of ethanol blend).

Automotive engines especially turbocharged diesel engines produce higher level of emissions during transient operation than in steady state. In order to improve understanding of the engine transients and develop advanced technologies to reduce the transient emissions, the engine researchers require accurate data acquisition and appropriate post-processing techniques which are capable of dealing with noise and synchronization issues. Four alternative automated methods namely FFT (Fast Fourier Transform), low-pass, linear and zero-phase filters were implemented on in-cylinder pressure. The data of each individual cycle was compared and analyzed for the suitability of combustion diagnostic. FFT filtering was the best suited method since it eliminated most pressure fluctuation and provided smooth rate of heat release profiles for each cycle.

The detection of needle displacement within a Common Rail injector is a crucial step to suitably characterize the behaviour of an injector. The needle motion is traditionally measured by means of an eddy current sensor. Apart from its high cost, scientific literature highlights its drawbacks, such as the introduction of mechanical weakness on the control piston as well as the electromagnetic disturbance affecting data acquisition. In order to provide an improved quality of signal, other solutions have been developed, which require a large number of components, leading to increased layout complexity. This layout can create a packing issue while mounting the sensor on the test rig. A novel sensor (UK Patent Application No.1819731.9) using fibre optic cable has been designed and built to overcome the limitations typically associated with needle displacement transducers.