Abstract

The recent developments of metallic Additive Manufacturing (AM) are regarded as beneficial for numerous engineering applications including biomedical, aerospace and power generation. Particularly in the field of gas turbine combustion, AM offers potential in manufacturing components with improved mechanical properties and increasingly complex geometry. Furthermore, AM can significantly decrease product development time and cost through rapid prototyping. In this direction, Cardiff University is currently investigating the influence of AM parameters on the efficiency of gaseous and liquid-fuelled gas turbine combustion systems. For example, current research includes an evaluation of the combustion and aerodynamic performance resulting from surface roughness variation in AM swirlers of well-characterized geometry, with respect to flame stability, turbulence intensity, and corresponding NO_x emissions. This effect was experimentally and numerically (CFD) assessed for lean premixed methane-air flames. Similarly, AM has been employed using an in-house Renishaw AM250 machine to produce a newly designed AM burner, suitable for co-firing ammonia-hydrogen blends. Furthermore, experimental work was carried out regarding the atomisation efficiency of multiple novel AM air-blast atomiser designs utilising aviation fuel, highlighting the benefit of AM in iterative product development.  In regards to the mechanical properties of AM components, the porosity of heavy-walled, pressure-retaining AM cooling nozzles was also assessed using high-powered CT scanning. Across multiple current research topics, the results show the potential for AM components to improve gas turbine combustion performance. By proving that geometries of increased complexity can be successfully built, some demonstrating multiple component integration, future research will look to utilize metallic AM to further improve gas turbine combustion stability and efficiency, with reduced emissions and enhanced fuel flexibility.