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Diesel engine performance and emission rely greatly on the diesel spray. A lot of researches conducted to study the diesel spray characteristics in a closed chamber. However, it cannot describe in detail about the phenomenon since the chamber condition such as pressure and size play a role in s pray characteristics. It would be beneficial to conduct an experiment in open chamber. Hence, this research would develop a new experiment apparatus and analyze the diesel spray characteristics in open chamber. In this research, common - rail injector tester is used to simulate the actual common - rail injection diesel engines. The injection pressure is varied from 100MPa to 180MPa. A high speed camera with 3,000 frames per second is used to capture the diesel spray formation using direct photography technique. From the result, spray development angle, and fully developed spray angle is studied. The results revealed early at the injection, the spray angle increased swiftly before slowly decreased as reaching fully developed spray phase. At the fully developed phase, spray angle proved to be decreased as the injection pressure increased.

Improvements in the diesel fuel injection systems can provide efficient combustion in internal combustion engine. However, the detail relationship between the diesel injector nozzle cavitation parameters are still remain unclear. The main goal of this research is to verify the flow characteristics inside the fuel injector nozzle by using CFD. A computational fluid dynamics cavitation models of diesel injector nozzles is presented and tested. Then, the experimental data are used to validate the models. The researcher used the same shape configeration and boundary condition. The injection event is inherently transient, as the injection pressure varies with the needle lift position. In order to capture this transient aspect within a steady-state formulation, this study performed simulations for different lift positions for the base nozzle. The results is done for the flow distribution for needle lift positions at 0.275 mm, 0.2 mm, 0.15 mm, and 0.1 mm. The corresponding velocity vector is plotted in order to explain the transient cavitation behavior. The velocity vectors for needle lift=0.275 mm indicate that the flow entering the orifice encounters a sharp bend (i.e., large velocity and pressure gradients) at the top of the orifice inlet causing cavitation in this region, However, with needle lift position at 0.15 mm, the flow entrance into the orifice is relatively smooth.

Direct imaging technique is always used to obtain correlation of flame height or any other parameter of the visible portions of the flame. This is one of the important methods used in the combustion community to determine the characteristic of flame. Recently, the imaging technique has been developed and enhanced to provide more accurate data. However the utilization of the technology, such as the used of laserbased technique and acquiring sensor, increased the complexity of the process and also increased the amount of cost practically. This paper presents the results of an acoustic excitation towards a Liquid petroleum gaseous flame by using the direct visualizing technique. The direct visualizing technique is used to acquire the flame image and the images will be analyzed by using image analysis software. Results show the flame length at the flame core decreases when the amount of acoustic gradually increases. The effect of excitation towards the flame core is being investigated due to its significant influence toward the overall flame characteristic.

Fire Safety Engineering is an application of science to improve the safety from the destructive effect of the fire. Paper is one of sources creating fire, however, research on flame spread towards paper is still not enough to describe about the phenomenon. Inspiration from this, the behavior of downward flame spread over paper/bagasse is experimentally investigated. Composition of 0%, 30%, 50%, 70% and 100% bagasse is determined for this research. Flame spread behavior for each composition is analyzed from the observation. Results show for each composition, the flame spreads with “U” shape at the beginning of combustion until the whole specimen. The result also shows that the flame spread rate decreases as bagasse composition increases. The highest flame spread is 0.8133 mm/s for pure paper and the lowest one is 0.4814 mm/s for pure bagasse. It infers that the flame spread shape and rate is influenced by the bagasse composition and density, respectively.Â