On December 10, 2018, Kyushu Yunjian (Beijing) Space Technology Co., Ltd. successfully conducted a short-range hot test run of the full-scale thrust chamber of the "Lingyun" 10-ton variable-thrust liquid oxygen methane rocket engine.

Test photo-working condition 1

Test photo-working condition 2
The results of this test are as follows:
(1) The combustion characteristics, heat transfer characteristics, and flow resistance characteristics of the thrust chamber are obtained, all of which meet the design expectations;
(2) The ignition matching and work coordination between the self-developed torch electric ignition system and the thrust chamber were assessed;
(3) The working reliability of the thrust chamber under a variety of thrust conditions was assessed.
The thrust chamber participating in this test is one of the key components of the reusable 10-ton liquid oxygen methane engine independently developed by Kyushu Yunjian. The thrust chamber has the following design features:
(1) Creatively design the flexible injection unit, which can be matched with various types and schemes of injection units according to the design intent, which is easy to realize the rapid optimization and iteration of the injection scheme;
(2) The extensive use of automated welding processes such as laser welding and electron beam welding is conducive to improving the weld strength and process consistency, and through 3D printing, precision CNC machining and other means, the number of welds in the entire thrust chamber is compared with traditional solutions Reduced by 90%, greatly improving structural reliability;
(3) The large-scale use of three-dimensional digital simulation methods to optimize the flow field and structure not only improves the design reliability, but also avoids expensive high-temperature alloy materials, and fully adopts ordinary metal materials, which greatly reduces product manufacturing costs.

Thrust room physical photos
Kyushu Yunjian "Lingyun" liquid oxygen methane engine is composed of main components such as turbo pump, thrust chamber, gas generator, igniter, valve and so on. Since the company started operations in January 2018, in accordance with the development process of first component test and then complete machine test, it has successively completed the cold and thermal tests of key components such as the igniter, gas generator, valve, thrust chamber, and thrust control valve.
As an engineering product, the thrust chamber that passed this test will continue to participate in the engine test to be carried out next year.

Engine mold assembly

About the thrust chamber squeeze test:
The thrust chamber is a device that generates high-temperature gas and thrust by a liquid rocket engine. It is composed of a combustion chamber and a nozzle. It is responsible for organizing and burning the high-pressure fuel and oxidant pumped by the turbine in the combustion chamber to produce high-temperature and high-pressure gas, which is then expanded through the nozzle to form high-speed gas and ejected outward, thereby generating thrust.
 

Schematic diagram of thrust chamber
In the overall state of the engine, the propellant from the low-pressure tank is pressurized by the turbo pump and then enters the thrust chamber for combustion, while the extrusion test is to pressurize the tank with high-pressure gas to squeeze the propellant into the thrust chamber. Therefore, the working conditions of the thrust chamber in the engine state can be simulated through the extrusion test, so as to verify the performance and structural reliability of the thrust chamber in advance, so as to improve the reliability of the whole machine test.