Progress in Burner Design Using Additive Manufacturing With a Monolithic Approach and Added Features

Additive manufacturing (AM) is a promising technology for producing better burners. Achieving better energy efficiency on a system level (CO2 emissions) and lower NOx, particulate emissions and CO, as directed by the International Civil Aviation Organisation (ICAO) standards, is a priority for all aircraft and aircraft engine manufacturers. At the current state-of-the-art, technologies like Powder Bed Fusion (PBF) offer a certain freedom of design one can make good use of. Instead of starting from an established conventional burner design and improve it using AM, the proposed approach in this paper is to define from scratch a design that maximises the potential benefits of AM towards a better burner. However, there are a few playing rules one must be aware of. The design, manufacturing and testing of a staged premixed burner with separate injection ramp was done as the follow-up of paper GT2018-75165 where new swirler shapes had been assessed. For this paper a monolithic, profiled burner design for premixed injection was tested for low-emission combustion. Additional features were included and assessed. Separately, regarding the fuel injection system a new design of a fuel ramp disconnected from the burner is proposed in a first approach, which combines the injection and pre-heating of the fuel. It serves as a fuel splitter (burning fuel / bypassed flow), as a miniature heat exchanger and as a multipoint injection ramp. A merging of the monolithic burner and the injection ramp is planned at a later stage. The fuel injection system using AM parts is assessed separately from the burner in a first approach. It suggests some novel technical solutions regarding 3D printed burner designs. Early combustion experiments are described and supported with function tests using a carefully selected instrumentation.