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This present work was focused on the application of the probability density function method in conjunction with the k-∊ turbulence model in the goal to predict temperature fields of a non-premixed confined natural gas diffusion flame. A combined experimental and computational fluid dynamics modeling study of the turbulent non-premixed natural gas on a laboratory scale has been performed. An experimental study has been carried out on a fire-tube water heater. The flame and gas temperature in the combustion chamber were measured. The real geometry of the fire-tube water heater and the burner were modeled and analyzed by FLUENT code numerically. Turbulent diffusion flames were investigated numerically using a finite volume method for the solution of the conservation and reaction equations governing the problem. The boundary conditions were specified as the same as the measured values. The elemental analysis of the natural gas was taken as the mixture of hydrocarbon, and the air was the oxidizer. The standard k-∊ model was used for the modeling of the turbulence phenomena in the combustor. The non-premixed combustion model was chosen. In the conserved scalar approach, turbulence effects are accounted for with the help of an assumed shape probability density function or probability density function. The discrete ordinates radiation model is used for modeling of the radiative heat transfer in the combustion room. The model results were compared with the experimental results, in good agreement with the measurements. [ABSTRACT FROM AUTHOR]

Biodiesel is an alternative diesel engine fuel. It should commonly be used as it is environmentalist and renewable. There are, of course, same doubts about its usage. The most important doubt is whether the utilization of biodiesel damages the engine or not. In this article, the research results obtained on biodiesel usage on an engine are presented. The cases that have to be taken care of by the biodiesel users and the effects of biodiesel used as fuel were determined. The present work has been realized to consider the influences of biodiesel on engine fuel system parts and engine components at real time and long-term conditions. [ABSTRACT FROM AUTHOR]

In this study, experiments are conducted to investigate charging and discharging characteristics of a paraffin as a phase change material (PCM). A vertical tube-in-shell geometry is designed to store the PCM. The thermophysical properties of the paraffin examined are determined through the differential scanning calorimeter (DSC) analysis. A series of experiments are carried out to investigate the effect of increasing the inlet temperature and the mass flow rate of the heat transfer fluid (HTF) both on the charging and discharging processes (i.e., melting and solidification) of the PCM. [ABSTRACT FROM AUTHOR]