Through metal 3D printing design, the engine injector of smile project has achieved excellent mixed combustion efficiency and lightweight characteristics, and the number of parts has been significantly reduced after integration, with 30 scattered parts integrated into an integral part

Challenge:

Design and manufacture of reusable liquid rocket engine injector for small satellite launch vehicle

Solution:

Based on rich design experience in additive manufacturing, 3D systems customer innovation center in Leuven uses metal 3D printer prox DMP 320 and a Ni Cr based super heat resistant alloy laserform for high temperature applications ® Ni718 (a) meets the requirements of German Space Center.

achievements:

• Optimize part characteristics to improve performance

• Integrate the injector components from 30 scattered components into one component

• Reduce the weight of spray head parts by 10%

One of the projects in the EU horizon 2020 program, called "European small innovative Launcher" (also known as smile project), aims to design a small satellite carrier rocket to put a small satellite (up to 150 kg) into orbit synchronized with the sun. The Institute for structure and design of the German Space Center in Stuttgart, Germany, is one of the 14 participating organizations and is responsible for the development of the smile project. The Institute's focus on liquid propulsion systems is based on the potential for system refurbishment and reuse to provide a more cost-effective solution for small satellite launchers.

In view of the high complexity of the components of the LOX / kerosene engine injector, the German Space Center DLR, in collaboration with the 3D systems customer innovation center CIC, has designed a 3D printing injector to achieve new performance. 3D systems Leuven center is one of the four centers in the world dedicated to accelerating advanced applications, providing customers with the resources they need to develop, validate and commercialize products.

The German space center decided to use 3D printing jet head. They took advantage of the key advantages of additive manufacturing, including the use of integral design to reduce the number of parts and the use of integrated key functions, such as cooling channels, to improve the performance of the overall propulsion system.

30 scattered parts are integrated into one integral part through metal 3D printing jet head, and the weight is reduced by 10%

Marcus Kuhn and Ilya Muller are managing the jet head project at the German Space Center. They said that because the metal printing of 3D systems has a successful application in the aerospace field, they chose 3D systems as their partner this time. "Based on the success of DMP metal printing technology in aviation, we believe that 3D systems is very suitable for the design and manufacture of jet heads, which can explore new possibilities of sensor integration, fuel and coolant distribution," Kuhn said

The injector of rocket engine is the part of fuel and oxidant entering the combustion chamber. Successful liquid rocket fuel injectors push the components in a specific way to ensure that they atomize and mix properly to produce the combustion required for a mobile rocket.

Cohen Whitt, a project engineer at 3D systems, said that the liquid fuel injection head envisioned by the German space center contains several properties that can only be achieved through DMP printing technology: "optimizing performance and cooling functions, pressure and temperature sensor channels

The complex design and simplified assembly and the consistency and repeatability of production all need prox ® DMP 320。”

The thermal test of 3D printing jet head shows that it has good mixing and combustion efficiency

DMP metal printing can help German Space Center achieve the following goals:

• Optimize part performance through new possibilities for fuel and coolant distribution

• Easy to realize 3D path pressure and temperature sensor channel

• Eliminate intermediate production and assembly links

• independent optimization of thermal, mass and hydraulic performance without limitation of traditional manufacturing methods

• Avoid assembly failure points and improve the quality of the overall design

• Reduce processing steps and produce high integrated multi-function injector

By using metal 3D printing, the Aerospace Center is able to completely change the design method of coaxial ejector, eliminating the need for multiple components and significantly reducing production time and cost. Reducing the number of parts from 30 to 1 is helpful to reduce the final weight by 10%, eliminate the known failure points of fasteners, reduce the related quality control measures, and improve the system performance.

Printing integrated components with precision metal

The application engineers of 3D systems use 3dxpert software to prepare the files of jet head for printing. 3dxpert is a comprehensive software, covering the entire metal additive manufacturing process. 3D systems is used to prepare for printing, so as to facilitate the post-processing of many powders in one place. At the same time, it is also used to check the printability, so as to ensure that there will be no problems in the printing process.