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Thermal ignition delay of the new fuel derived from Jojoba Seeds and its blends with diesel fuel and methanol has been measured. For this purpose, a shock-tube test set-up was designed and manufactured. It was instrumented for delay measurement with piezo-electric pressure transducers, charge amplifiers, storage oscilloscope and electronic plotter. The test variables included the type of fuel (Jojoba Methyl Ester and its blends with Gas oil and Methanol), equivalence ratio, ignition pressure and ignition temperature. The activation energy of the new fuel as well as its blends with Gas Oil and Methanol was evaluated through the use of Arrhenius plots. The results have shown that the Jojoba methyl ester has superior ignition characteristics to Gas oil and Methanol and the blend with them. The suitability of such promising fuels for diesel engines is highlighted. A correlation was developed to predict the effect of variables which read:

The in cylinder air motion, fuel air mixing, evaporation, combustion and exhaust emissions have been simulated for a four stroke direct injection gasoline engine using the KIVA II code. A strong controlled tumbling air motion was created in the cylinder, through a combination of a conventional pentroof four valve cylinder head, in conjunction with a piston having a stepped crown and offset combustion bowl. A range of injection strategies were employed to optimise combustion rate and exhaust emission (NOx and unburned hydrocarbons (fuel)), at two operating conditions - one with a stoichiometric air fuel mixture and the other with a lean mixture of 30:1 air/fuel ratio. Injection directed towards the piston bowl with a hollow cone jet, in a single pulse, has shown the best results regarding burned mass fraction and level of unburned HC. Fuel concentration, air motion, combustion characteristics and pollutants level are presented for lean and stoichiometric cases.

Flying Hot-wire anemometer measurements have revealed the effect of the inlet port angle, and valve lift on the spatial structure of turbulence in a model internal combustion engine. The present experiments are carried out at the BDC, intake stroke at a low piston speed in a dynamically similar flow. The data are presented using both cycle resolved and ensemble averaging techniques. The experiments are carried out at three different measurement positions across the engine cylinder. The inhomogeneity of the intake turbulence is found to be considerable. The role of the inlet jet flow is shown to be crucial.

Lean burn spark-ignition engines (S.I.E) are currently under scrutiny for their fuel economy and pollution reduction potential while using fuels with ordinary anti-knock quality. This study was concentrated on turbulence generation in a simulated inlet manifold of S.I.E. via the use of several designs of turbulence generators. A special test set-up was specifically designed and built for this study, and special measuring probes were constructed, developed and calibrated to find out the turbulence level behind each turbulence generator. Four types of swirl and turbulence generators were used and tested to find out the optimum design and operational parameters. The investigation has been carried out using air as the working medium, while the effect of flow velocity, temperature and turbulence generator design parameters were studied and their effect on the relative turbulence kinetic energy was experimentally found out.