Engineering an afterburner for a miniature gas turbine engine

Purpose - This paper is concerned with the theoretical and practical engineering development issues, necessary for the design, build and test of an afterburner thrust augmentation system for a model aircraft gas turbine engine. Design/methodology/approach - Research into key combustion parameters including, flame holder diameter, flame holder edge velocity, burner velocity and equivalence ratio were undertaken. This information was used as the basis for the design and fabrication of the afterburner combustion system. The after burner system had been designed to fit a Wren MW54 model gas turbine engine, that included FADEC control for the mother engine. Substantial testing of the afterburner system was undertaken. Findings - Changes in "dry" and "wet" jet efflux temperature while the engine is accelerating from idle to full power are found. The increase in temperature between the dry and wet case are not markedly different, demonstrating the poor quality of the afterburner flame: the testing of the afterburner system resulted in limited flame substantiation being achieved. Research limitations/implications - Further research is required and is currently being undertaken, into the computational modelling of fuel atomisation issues and further engineering of the fuel injection system. Practical implications - This afterburner design may eventually be adopted by Wren Turbines for economic production. Originality/value - Provides further information on the engineering and efficiency problems associated with very small-scale gas turbine engines.