Thermal Efficiency Study of the Combustion Chamber Designed for Small Scale Gas Turbine Engine Transformed from Turbocharger

Turbocharger and gas turbine engine have similar working principle, but different applications. By substituting internal combustion engine of a car with combustion chamber, a turbocharger is able to transform into a small scale gas turbine engine. The key objective of this project is the study of thermal efficiency of combustion chamber model which designed for Garrett GT2860R Turbocharger. A set of combustion chamber outlet temperature contour is determined through manipulating the casing diameter of the combustion chamber model. Theoretically, outlet temperature is directly proportional to thermal efficiency, high outlet temperature of combustion chamber indicates high thermal efficiency of combustion chamber. Graph of average outlet temperature versus casing diameter is plotted in order to study the effect of casing diameter on outlet temperature. Further discussion on the temperature contours and graph is done to explain the results obtained in details. Findings show that casing diameter of combustion chamber has effect on the outlet temperature. Increasing or decreasing the casing diameter from an optimum diameter for a specific length of combustion chamber reduces its thermal efficiency. Casing length-to-diameter ratio of 3 yields the highest thermal efficiency and uniform temperature distribution. Comparison of the pattern of temperature contour is also done to verify the modeling and simulation approach of this project.