Recently, JiuZhou Yunjian "Lingyun" 10-ton liquid oxygen methane rocket engine completed a large-scale continuous variable thrust hot test. This test was carried out at the 100-ton double-station test base independently constructed by JiuZhou Yunjian, and the test was a complete success .

　　This test has the following characteristics:

　　① After Lingyun Engine took the lead in completing the variable thrust hot test in 2019, the length of the test and the number of variable thrusts have been greatly increased;

　　②The measured thrust adjustment range of Lingyun engine this time is 100%-38%, and the adjustment ability has reached the world's leading level;

　　③This test covers the mission profile requirements of the target rocket's flight test.

Large-scale continuous variable thrust hot test run of Lingyun liquid oxygen methane engine

(Thrust changes after 100s of rated work)

　　What is the large-range thrust adjustment of a liquid rocket engine?

　　Vertical recovery launch vehicle can significantly reduce launch costs, and at the same time has broad prospects for derivative applications. At present, the key bottleneck restricting the development of my country's vertical recovery rocket lies in the liquid rocket engine. For a rocket to achieve vertical recovery, in addition to the ability of the engine to be able to start more than three times, it also needs to adjust the thrust of the engine in a wide range before landing. A very low level can make the rocket land smoothly. If the thrust adjustment range of the engine cannot reach the 60% level, it will be difficult to achieve a safe landing of the rocket. The larger the engine's thrust adjustment range, the better the response characteristics, and the higher the "fault tolerance" during the rocket recovery process. The actual test of the Lingyun engine can be throttled to 20% operating conditions. This test is a continuous adjustment of 100%-38% operating conditions, which once again assessed the engine's variable thrust capability and reliability.

Before and after the 100%-38% change of "Lingyun" liquid oxygen methane rocket engine

　　What is the difference between this test run and the deep variable thrust test run completed in 2019?

　　Lingyun engine has broken through the deep thrust adjustment technology in 2019, and took the lead in the deep variable thrust hot test in China, but due to the limitations of the test conditions at the time, the testable thrust range and test time were relatively limited. In 2020, JiuZhou Yunjian began to independently build an intelligent engine test base, aiming to provide stable and reliable hot test conditions for the "Lingyun" and "Longyun" engines. The thrust level of the intelligent test base covers a scale of 100 tons. It supports the two types of engines for various tests. This large-scale continuous variable working condition hot test was completed at the independent test base. It can be seen that the Lingyun engine's test duration and the number of variable thrusts far exceed the test in 2019, which more effectively assesses the depth of the Lingyun engine. Reliability of thrust technology.

2019 Lingyun engine deep variable thrust hot test run picture

　　The follow-up "Lingyun" engine will continue to carry out various assessments such as reliability accumulation and working conditions deviation, and solidify the engine technology innovation and reliability. In addition, technologies such as "Longyun" engine multiple starts, deep thrust adjustment, low-cost and quick use and maintenance can help accelerate the development of "Longyun" recyclable engines. At present, "Longyun" engines have completed the semi-system hot test assessment, which is expected to be Carry out the whole system test this year.