Successful Ignition Test of the Liquid Oxygen-Methane Rocket Engine Thrust Chamber

On December 10, 2018, Jiuzhou Cloud Arrow (Beijing) Space Technology Co., Ltd. successfully conducted a short-duration thermal test of the full-scale thrust chamber for the "Lingyun" 10-ton variable-thrust liquid oxygen-methane rocket engine.

Test Photo – Condition 1

Test Photo – Condition 2

The following results were achieved in this experiment:
(1) The thrust chamber's combustion characteristics, heat transfer characteristics, and flow resistance characteristics were all found to meet the design expectations.
(2) The ignition matching and operational coordination between the self-developed torch electric ignition system and the thrust chamber were evaluated.
(3) The reliability of the thrust chamber under various thrust conditions was assessed.

The thrust chamber participating in this test is a key component of Jiuzhou Yunjian's independently developed, reusable 10-ton liquid oxygen-methane engine. This thrust chamber features the following design characteristics:
(1) Creatively designed flexible injection units allow for the easy combination of various types and configurations of injection modules according to design requirements, facilitating rapid optimization and iterative improvements in injection strategies.
(2) The widespread adoption of automated welding processes such as laser welding and electron beam welding helps enhance weld strength and process consistency. Additionally, through methods like 3D printing and precision CNC machining, the number of weld seams in the entire thrust chamber has been reduced by 90% compared to traditional approaches, significantly improving structural reliability.
(3) Extensive use of 3D digital simulation techniques for flow field and structural optimization has not only enhanced design reliability but also eliminated the need for costly high-temperature alloy materials, instead fully adopting conventional metal materials, thereby significantly reducing product manufacturing costs.

Physical photograph of the thrust chamber

The Jiuzhou Yunjian "Lingyun" liquid oxygen-methane engine consists of key components such as a turbopump, thrust chamber, gas generator, igniter, and valves. Since commencing operations in January 2018, the company has followed a development process that prioritizes component-level testing before progressing to full-engine tests. As a result, it has successfully completed cold and hot tests for critical components, including the igniter, gas generator, valves, thrust chamber, and thrust regulation valve.
The thrust chamber that successfully passed this test evaluation will continue to participate in the full-engine tests scheduled for next year as an engineering product.

Engine Module Assembly

Regarding the Thrust Chamber Compression Test:
The thrust chamber is the component of a liquid rocket engine responsible for generating high-temperature gases and producing thrust. It consists of a combustion chamber and a nozzle. The thrust chamber orchestrates the combustion process within the combustion chamber, where the high-pressure fuel and oxidizer delivered by the turbopump are ignited to produce high-temperature, high-pressure gases. These gases then expand through the nozzle, accelerating into a high-speed jet that is expelled outward, thereby generating the necessary thrust.

Thrust Chamber Diagram

In the complete engine state, propellants from the low-pressure tank are pressurized by the turbopump before entering the thrust chamber for combustion. In contrast, the squeeze test involves using high-pressure gas to pressurize the tank, thereby forcing the propellants into the thrust chamber. Therefore, the squeeze test can simulate the operational conditions of the thrust chamber under engine conditions, allowing for early assessment and verification of both the thrust chamber's performance and structural reliability, ultimately enhancing the overall reliability of the complete engine testing process.