Advanced metal AM enables microturbines to be 40X more efficient

A microturbine has historically been a simplified version of a gas turbine, suitable for a variety of applications: they are used in unmanned aerial vehicles (UAVs), to charge the batteries that drive motors, as range extenders, or in hybrid UAVs that alternate between batteries and motors. In the US, Sierra Turbines has been breaking the rules of conventional manufacturing to improve the performance of microturbines. Roger Smith, Chief Executive Officer, explains that the company plans to additively manufacture at least 95% of their microturbine components, even when the company reaches large scale production. To do so, the company decided to collaborate with VELO3D, relying on its proprietary support-less metal additive manufacturing technology. Their aim is to make their turbines 40x more efficient by providing 10x more power density and reducing weight by 50% compared to traditional microturbines.

Additive manufacturing technologies will not replace traditional manufacturing methods, but they can certainly boost performance for applications where design has not been optimized yet. This is the case of microturbines, where cost restrictions have always prohibited manufacturing complex features that would improve performance. The time between overhaul (TBO) for most small turbine engines averages 40 to 50 hours but Roger Smith intends to raise that value to 1000+ hours, on par with commercial aircraft. He also plans to reduce engine weight by half, cut noise, and improve fuel efficiency, all while making the turbines easier to manufacture. These are ambitious goals to say the least!

Two 3D-printed turbine combustors that serve as the core of Sierra Turbines’ small engine | Photo courtesy of VELO3D

Roger Smith explains that he is confident that his team will succeed where others have failed thanks to a host of design improvements only made possible with advanced metal AM. This is where VELO3D’s support-free capabilities and their dedicated AM software Flow come in. Today, some designs are impossible to manufacture with powder-based metal AM technologies without supports, adding additional post-processing steps to remove them, therefore increasing costs and limiting design freedom. Ultimately, support-free technology enables more complex components to be manufactured.