The project effort is to demonstrate environmental advantages such as a reduction of thrust specific fuel consumption and noise abatement of a newly developed low cost additive manufactured (AM) micro-turbine engine over current micro turbine power plants with traditional designs. Across all services of the Department of Defense (DoD) there is a continual need for power plants that yield a reduced environmental impact through improved efficiency and a reduction in noise emissions. Existing turbine engines have a number of barriers which have prevented their more prolific application. The obvious barriers are high initial cost, relatively high maintenance and life cycle costs, and most of all the high frequency noise that is harmful to humans if not controlled. The following technical objectives will be accomplished: Objective 1: Demonstrate AM micro turbine for multiple applications, ensuring cost effectiveness of newly developed AM turbine engine for DoD services; Objective 2: Demonstrate improved performance in thrust specific fuel consumption and noise emissions of AM micro turbine engine by establishing baseline performance criteria and performing geometry optimization (as required); Objective 3: Validate reduced thrust specific fuel consumption and noise emissions of AM micro turbine and provide recommendations for implementation at DoD installations.

Project effort will utilize commercially available EOS M290 Additive Manufacturing machines to build AM micro turbines, employing a powder bed fusion, direct metal laser melting (DMLM) technology that uses lasers to melt ultra-thin layers of metal powder to build a three-dimensional part. Parts can be built directly from a computer-aided design model. DMLM makes possible a design-driven process with significant benefits.

Rapid technological innovations over the past few years have boosted the efficiency of larger turbine engines, approaching 80% energy efficiency. As yet, the innovations and improvements developed for the large scale engines have not made it into the micro-turbine engine world. Traditionally, the turbine engine as a power plant, especially on the micro scale, has a higher capital and investment cost to the user than its piston driven counterparts. With the new manufacturing processes available to us today, these cost gaps can be reduced by an order of magnitude. With the use of AM, it is believed that many of the fuel efficiency concepts can be incorporated into a micro-design. Iterative design cycles will be used to evaluate the practical application of these noise reduction concepts from larger engines as well as enabling the development of novel solutions. The environmental impact from AM engine production will benefit in energy saving, carbon footprint reduction, waste management, etc. The advantages of AM technologies offer capabilities to rapidly prototype and manufacture a micro-turbine with following expected benefits: Cost effectiveness of newly designed AM micro-turbine engine; reduced carbon footprint through less CO2 emissions from a cleaner AM engine production process; reduced perceived noise emissions through advanced/optimized geometry; improved thrust specific fuel consumption efficiency which is directly linked to the fuel consumed by the engine and the emissions. Additive Manufacturing is taking increasing part in micro-turbine production offering not only cost reduction, but additional benefits such as capabilities to develop optimized model design to maximize performance characteristics reducing noise and improving fuel consumption. The new capability to manufacture truly optimized models will have far reaching environmental impacts starting with a reduction in fuel consumption and a reduction of noise pollution.

DISTRIBUTION STATEMENT A: Approved for Public Release; AFLCMC-2020-0073 24 March 2020