Morgan Stanley estimates that by 2040, the revenue of the global aerospace industry will grow from the current US$350 billion to a market size of more than US$1 trillion. According to market observations from 3D Science Valley, Space X created by Elon Musk and Blue Origin created by Amazon CEO Jeff Bezos may be one of the largest players in the industry. In addition, there are startups such as Launcher and Relativity Space that started late.
Relativity Space, a start-up at the helm of the post-90s generation, is turning the tide of financing to3D printingCreate an entire rocket to launch a strong offensive. Just in October 2019, Relativity Space raised a new round of financing of 140 million U.S. dollars (1 billion yuan). Another young company, Rocket Lab (founded in 2006), has received a total of more than 215 million U.S. dollars (1.5 billion yuan) in financing.
Behind such strong financing is the huge market space of the aerospace industry on the one hand, and the unique rocket manufacturing technology of emerging rocket companies on the other.In this issue, 3D Science Valley special sharing3D printingAnalysis of rocket engine thrust chamber, ejector and turbo pump patents.
Source: Patent US10527003B1 approved by Rocket Lab (Authorization Date: January 7, 2020)
3D printingGenerate complex parts with integrated structure
Recently, Rocket Lab’s patent US10527003B1 (authorization date: January 7, 2020) disclosed in detail Rocket Lab’s use of additive manufacturing processes to manufacture rocket thrust chambers, injectors and turbo pumps for rocket engines.
Detail drawing of isometric cutaway view. Source: Patent US10527003B1 approved by Rocket Lab (Authorization Date: January 7, 2020)
Traditional turbopump assemblies used in rocket engines typically include a centrifugal propellant pump driven by one or more turbomachines. The control of this system is very complicated, because a small amount of propellant from the propellant pump is needed to supply the gas generator to power the turbine.
Side view and top view of the impeller of the electric turbo pump. Source: Patent US10527003B1 approved by Rocket Lab (Authorization Date: January 7, 2020)
Rocket lab’s patent confirms that the use of additive manufacturing technology for the production of turbopump components can greatly simplify the assembly of this system, and the manufacturing of various components through the selective metal melting process will greatly reduce the assembly complexity of this system.3D printing-Additive manufacturing technology allows the formation of complex geometric shapes, which is difficult or impossible to achieve using traditional subtractive processing technology or casting/injection molding technology.3D printingThis flexibility of technology provides unique opportunities in the field of rocket engine design.
An exploded side view of the thrust chamber. Source: Patent US10527003B1 approved by Rocket Lab (Authorization Date: January 7, 2020)
As can be seen from the exploded side view of the thrust chamber, the ejector 122 can be inserted between the cover 105 and the barrel portion 102. The thrust chamber is manufactured by additive manufacturing technology, the material is titanium alloy, and the throat 103 and the expansion part 104 can be formed as a single piece by additive manufacturing. The thrust chamber is formed by three parts. Because the thrust chamber has a double-wall structure, Rocket Lab has developed a welding method to combine multiple parts together.
It is worth mentioning that due to the structure of this engine, it is very problematic to control the surface roughness of the coolant flow passage 110 in the conventional rocket engine. In this conventionally manufactured rocket engine, the ability to control the surface finish in the coolant flow channel is very small, because after the coolant flow channel is formed, it is usually impossible to enter the inner surface of the channel.
In contrast, the use of additive manufacturing techniques to form the part of the thrust chamber provides a relatively unique capability that exists on two levels:
First, it is possible to design small bump features, ridges, protrusions, valleys, etc., which are used to provide local changes in specific areas of the coolant flow channel.
Second, by adjusting the processing parameters and powders of additive manufacturing technology, different surface roughness can be produced.For example, laser melting of metal in selected areas3D printingThe average particle size of the powder particles commonly used in the processing can usually be between 30 μm and 110 μm.
Changing the surface roughness in the coolant flow channel can also provide increased heat transfer characteristics, which can compensate to some extent the thermal characteristics of the material used to form the thrust chamber. For example, copper is commonly used in traditional thrust chambers.3D printingThe thrust chamber can use titanium alloys (including Ti.sub.6Al.sub.4V), steel alloys (including stainless steel alloys and maraging steel alloys) and Inconel alloys (such as Inconel.RTM.625 (UNS N06625) or Inconel .RTM.718 (UNS N07718)), because the thermal conductivity of these materials is one or two orders of magnitude lower than that of copper. Compared with copper, changing the surface roughness in the coolant flow channel can compensate to some extent for the reduced thermal conductivity of these materials.
Of course, copper alloys are now gradually being included in the constituency of metal melting3D printingWithin the scope of processing, among them, NASA succeeded3D printingThe parts of the copper alloy combustion chamber are produced. There are more than 200 complicated passages between the outer walls of the combustion chamber.And domestic metal3D printingThe company Blite has made progress in the field of copper metal laser forming, and has developed products for refractory metals and high thermal conductivity and high reflective metals3D printingProcess, realized the copper material manufacturing process of the complex runner, successfully prepared3D printingCopper alloy tail nozzle.
Rocket lab’s patent shows that additive manufacturing or3D printingTo manufacture the ejector 122. According to the market research of 3D Science Valley, the ejector can be a structure-integrated overall structure without the need for connection between components, which provides the ejector with strength and reliability. The selective laser melting process may result in a rough surface on the finished product, which can be removed or cleaned with abrasives. However, the surface roughness has a positive effect. The turbulence in the propellant flow caused by the surface roughness may assist atomization when the propellant flow hits.
(Editor in charge: admin)
0 Comments for “See through 3D printed rocket engine thrust chamber, ejector and turbo pump patent”