A Redesigned and 3D Printed Rocket Nozzle

The printed nozzle project was created to improve the design and functionality of the nozzle within high-power rocketry applications using additive manufacturing (AM). This AM method has become increasingly popular amongst major rocket companies due to large costs and design challenges that limit conventional manufacturing methods.

The AM process offers several advantages such as a significant weight reduction, simplified assembly, and a generative design method with intricate internal geometries that cannot be offered through other methods. These intricate design methods allow for novel cooling strategies, which utilize hollow cavities within the structure. The AM-printed nozzle allows for easy integration of the necessary fluid paths within the walls, which absorb the heat and prevent overheating of the structure. To compensate for the lack of stiffness within the hollow walls, an internal lattice structure is introduced for mechanical stiffness.

(Left) Thermal performance of the engine burn. (Right) Optimization Results.

Upon testing, it was found that the nozzle performed as expected during combustion testing in ideal conditions. However, water was unexpectedly ejected from the steam valve, thus eliminating the intended cooling feature, and the nozzle was heated beyond the operating temperature which resulted in damage.

The nozzle was printed within the MSAM facility in Inconel 625 using an LPBF (Laser powder bed fusion) system.

(Left) Printed Nozzle highlighting lattice structure. (Right) Testing of nozzle.

For additional information, visit YouTube for the video “Kismet –Static Fire #5Left Picam”.