In March last year, Galactic Energy Space Technology Co Ltd, headquartered in Beijing, China, one of China’s leading commercial aerospace companies, announced the first successful full-system test flight of its Welkin 50-ton (sea-level thrust) reusable LOX/kerosene engine. Several of the key components of the engine – including the turbo pump and the LOX/kerosene main valve housing – are additively manufactured by Falcontech, Wuxi City, using a Laser Beam Powder Bed Fusion (PBF-LB) machine from Farsoon Technologies, headquartered in Changsha.
The aim of Galactic Energy’s full-system test was to verify the engine operation, structural design, and coordination of each assembly. During the test flight, the engine’s ignition, starting, and transition were tested for performance, with gathered data showing that each component worked as expected. The combustion process was reported to be stable, and the major performance parameters observed were consistent with the calculated data values. The test achieved complete success with the engine remaining intact, and in a reusable condition, after the test.
In July 2019, Galactic Energy partnered with Falcontech on the project, resulting in more than thirty metal parts of various sizes being additively manufactured and accepted by Galactic Energy in just four months.
Utilising AM as a part of a larger manufacturing process was said to be a true breakthrough in the development of commercial rocket engines in China. To date, the Welkin engine is reputedly the highest thrust LOX/kerosene engine in the Chinese commercial aerospace field. The Welkin is also said to be the first large-thrust liquid rocket from China to adopt pintle injection technology. The thrust chamber of a high-thrust liquid rocket engine usually adopts active regenerative cooling for the combustion chamber’s thermal protection. With conventional manufacturing technologies, the manufacturing process of thrust chamber components is extremely complicated and usually takes several months. A slight production variation in one single component may lead to the functional test failure of the whole thrust chamber.
During the design phase of the turbo pump, the Galactic Energy engineering team compared the efficiency of two models: one designed for the conventional manufacturing process and the other for Additive Manufacturing. The new AM design improved production efficiency by 5%.
Significant efficiencies were also seen in the design and manufacturing of the turbine disks, where the traditional machining will take twenty to twenty-five days, but takes only three to four days using Additive Manufacturing. Here, the manufacturing cycle was shortened by 80%.
In further development of its Welkin LOX/kerosene engine, Galactic Energy has reported that it sees many opportunities to use AM, specifically targeting lightweight, high-strength components and improved part reliability.