European Space Agency launches first hot test of full-size 3D printed copper alloy thrust chamber

On May 26, 2020, the European Space Agency (ESA) conducted a hot test run of a fully additively manufactured rocket thrust chamber at the German Aerospace Center (DLR). The first test lasted 30 seconds, and other tests are expected within this week. ESA will collect and analyze the test data.

Under test3D printingThrust chamber. Source: ESA

Integrated cooling runner

According to ESA, tested3D printingThe thrust chamber has only three parts, which can provide power for the upper layer of future rockets. The number of additive manufacturing thrust chamber parts has been reduced from hundreds to three, shortening production time, lowering costs, and significantly improving the competitiveness of liquid propulsion engines in European launch vehicles.

The full-size thrust chamber for testing has3D printingCopper alloy lining, the lining has an integrated cooling channel, and its outer layer is a high-strength outer jacket built by cold air spraying.3D printingThe manifold and integral fuel injection of the thrust chamber are also additively manufactured.These3D printingThe production and testing of the parts have been carried out in ESA’s “Future Launcher” preparation plan.

ESA said that the full size of this test3D printingThe thrust chamber is based on the technology and method verified in the ETID (Expander-cycle Technology Integrated Demonstrator-ETID) hot test run in 2019. ESA has tested four configurations of ETID. ETID has three new combustor geometries and designs.Two different injector heads were also tested, including full3D printingThe nozzle, and a regenerative nozzle, the nozzle optimizes the engine cycle by absorbing heat to the maximum extent. Both the combustion chamber and the nozzle use the heat of combustion to preheat, thus “expanding” the hydrogen propellant before combustion. The flow of cold hydrogen also has the effect of cooling the hardware, keeping the temperature within a reasonable range during operation.

ESA conducted a total of 23 tests on ETID, with a total running time of 2707s. During the test, 49 different operating points were reached, including testing behaviors under “extreme” conditions, such as increasing the flow of cold hydrogen in the system, and therefore “subcooling” the hardware during operation. The test shows the versatility of the ETID design and can operate in a wide range of mixing ratio and chamber pressure. Multiple operating points will also aid in calibration, which is used to design a numerical model for subsequent engine design and predict its performance.

Review

Since May this year, we have seen aerospace3D printingThe impressive results achieved by the application.

At 18:00 on May 5th, the Long March 5B rocket, a new member of the “Fat Five” family, carried a new generation of manned spacecraft test ship and a flexible inflatable cargo return cabin test cabin, ignited from the Hainan Wenchang Space Launch Site and officially opened. This marks the prelude to the “third step” mission of my country’s manned space project.The new generation of manned spacecraft test ship not only completed the first time3D printingSpace experiment, also equipped with the world’s first metal-based3D printingTechnicalCube Star Deployer.At the same time, the entire 211 plant developed by China Aerospace Science and Technology Corporation3D printingThe core-level bundled support successfully passed the flight assessment and verification.

May 31st, Beijing time,SpaceX The latest Crew Dragon spacecraft was successfully launched on launch pad 39A of the Kennedy Space Center in the United States. The launch vehicle Falcon 9 and Crew Dragon spacecraft and two astronaut helmets are being manufactured,3D printingBoth played an important role.

3D printingIt has become a core technology in the field of aerospace manufacturing, and there is no need to say more about it. Especially in the field of rocket engine manufacturing,3D printingIt has become an important “bargaining chip” for aerospace manufacturing institutions to seize the next generation of economical and reusable rocket engines.Involved in ESA’s recent test drive3D printingThe thrust chamber is a key competition track for the additive manufacturing of rocket engines.

l The trend of “a hundred schools of thought”

Copper alloy thrust chamber components

Aerojet Rocketdyne uses powder bed selective laser melting3D printingTechnically manufacturedCopper alloyThe thrust chamber components passed the ignition test conducted by the Defense Production Act Title III Project Management Office of the United States in 2017.Passed the test3D printingThe copper alloy thrust chamber components are full-size. This thrust chamber will replace the thrust chamber components of the current RL10C-1 engine.3D printingThe copper alloy thrust chamber component is composed of two copper alloy parts.Compared with traditional manufacturing process, selective laser melting3D printingTechnology has brought a higher degree of freedom to the design of the thrust chamber, allowing designers to try advanced structures with higher thermal conductivity, such as integrated internal cold channels. The enhanced heat transfer capability makes the design of the rocket engine more compact and lightweight, which is exactly what the rocket launch technology needs.

NASA made copper alloy parts in 20153D printingIn terms of progress, the manufacturing technology is also selected by laser melting3D printing, The printing material is GRCo-84 copper alloy. NASA uses this technology to make3D printingThe part is the lining of the rocket combustion chamber. The part is divided into 8,255 layers and printed layer by layer. The printing time is 10 days and 18 hours. In 2019, NASA announced a new type of copper alloy3D printingMaterial GRCop-42, which is a high-strength, high-conductivity copper-based alloy material that can be used to produce nearly completely dense3D printingComponents, such as rocket combustor lining and fuel injector panel.

Nickel-based superalloy integrated thrust chamber

Material: IN718 nickel-chromium alloy; Equipment: SLM®280. Source: SLM Solutions

CellCore has worked closely with SLM Solutions to use nickel-based superalloys and selective laser melting technology to successfully achieve the integrated molding of the multifunctional thrust chamber.exist3D printingIn the thrust chamber, the cooling pipe is part of the design and is formed with the entire cavity in the same production process. The integrated rocket engine, combined with the ejector and thrust chamber, simplifies many individual components into one. Only through the laser selective melting process can a multi-functional integrated lightweight structure be realized. The internal structure developed by CellCore covers the entire rocket engine, which is not only suitable for heat transfer, but also improves the structural stability of the components.

Integrate more than 100 cooling channels

In 2019, China’s Deep Blue Aerospace liquid oxygen kerosene engine once again carried out a long-distance test run of the thrust chamber and achieved complete success.In terms of thrust performance, Deep Blue Aerospace optimizes the design of main functional components and uses a large number of3D printingThe technology has achieved a technological leap in the efficiency of the thrust chamber of the domestic liquid oxygen kerosene rocket engine from 95% to 99%, reaching the international advanced level.

Source: Deep Blue Aerospace

Blite undertook the test engineInjector housing and thrust chamberMetal of the two parts of the body3D printingWork. Engine injector shell and thrust chamber body are the key components of aerospace engine. The use environment is harsh. There are more than 100 cooling channels inside the parts. The traditional milling and welding processes not only have a long manufacturing cycle, high cost, and part performance. It is also difficult to be guaranteed.

Control the surface roughness of the internal cooling channel

Rocket Lab, a young aerospace company, has deployed intellectual property rights in the field of rocket engine thrust chamber manufacturing. According to market observations from 3D Science Valley, in related patents, Rocket Lab emphasizes the unique ability of selective laser melting technology to control the surface roughness of rocket engine coolant flow channels:

First of all, additive manufacturing can realize the design of small bumps, 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.

The above3D printingAlthough the case is only the tip of the iceberg in the aerospace engine additive manufacturing track, it can still be seen that when the laser selective melting technology is used for additive manufacturing, the cooling channel directly becomes a part of the overall design, and is in the same production process. The whole cavity is formed together, which is also3D printingIt is applied to the thrust room and other thermal management fields.

about3D printingIn the application of aerospace engine manufacturing, 3D Science Valley has published “3D printingAnd aerospace manufacturing white paper“.3D printingThe parts that were originally combined by multiple components can be integrated and printed, which not only realizes the integrated structure of the parts, avoids the connection structure (flanges, welds, etc.) that exist when the original multiple parts are combined, and can also help design It breaks the constraints and realizes the optimal design of functions. The realization of the integrated structure not only brings the advantages of light weight, but also reduces the need for assembly and opens up feasible space for enterprises to improve production efficiency.

(Editor in charge: admin)