The thrust regulation system for the "Lingyun" liquid oxygen-methane rocket engine has successfully completed a semi-physical simulation test.

In November 2018, the thrust regulation system of Jiuzhou Yunjian's "Lingyun" liquid oxygen-methane rocket engine successfully completed its first round of semi-physical simulation tests. These tests involved comprehensive system-level evaluations of key variable-thrust components, including the engine thrust controller, regulator valve driver, and electrically actuated regulating valve. The trials thoroughly validated the operational compatibility between the thrust regulation control system and the overall engine architecture, as well as the functional adaptability of the control drivers and the rationality of the underlying control logic. This successful completion of the semi-physical simulation marks the first breakthrough in domestic semi-physical simulation technology applied to pump-fed liquid rocket engines, laying a solid foundation for the development of variable-thrust engines.

On-site Semi-Physical Simulation Test

The following achievements have been obtained through this semi-physical simulation test:

• The engine control and motor drive systems adopt an integrated design approach, significantly simplifying the system and reducing the weight of the control unit.

Control the drive

• A low-cost electric control valve with independent intellectual property rights, which has achieved breakthroughs in key technologies such as high-pressure dynamic sealing, rapid response, and resistance to vibration and impact for electric control valves.

Electrically Actuated Control Valve

• Self-developed software for motor drive and engine thrust control, ensuring independent control over core technologies.
• A variety of control algorithms adaptable to the overall requirements of the rocket, selectable based on the rocket's specific mission needs.
• A real-time and computationally accurate engine hardware-in-the-loop simulation model.

Rocket reusability technology is a crucial approach to reducing launch costs. Commercial aerospace companies such as SpaceX and Blue Origin in the United States have vigorously pursued the development of rocket reusability technologies, significantly lowering launch expenses through the partial recovery and reuse of rockets. To achieve rocket reusability, the propulsion system must overcome at least two key technological challenges: First, it requires advanced multiple ignition and startup capabilities for the engine. During the rocket's return journey, the engine performs multiple ignitions and other maneuvers to precisely control its trajectory, ensuring a safe landing at the designated site. Second, the system must feature deep thrust modulation technology, enabling continuous and precise adjustments in engine thrust throughout the descent phase. This allows the rocket to decelerate effectively, meeting stringent safety requirements for a controlled and secure touchdown. The "Lingyun" liquid oxygen-methane engine developed by Jiuzhou Rocket Company was designed from the outset with reusability as its core principle. Aligning with international cutting-edge standards, this engine boasts exceptional performance, including the ability to undergo dozens of successful ignitions and offering seamless, stepless thrust regulation ranging from 30% to 100%.

The semi-physical simulation test of the thrust regulation system represents another critical validation experiment conducted by Jiuzhou Cloud Arrow, following their previous tests on the torch-type electric igniter and the long-range variable-thrust testing of engine subsystems. This test focuses on the core technology of low-cost, reusable commercial launch vehicle propulsion systems. The successful completion of the semi-physical simulation underscores Jiuzhou Cloud Arrow's breakthrough in overcoming the control challenges associated with deep-thrust regulation in pump-fed liquid rocket engines. It also marks an initial achievement in mastering the engine thrust control technology essential for enabling both rocket recovery and propulsion system reuse—key milestones that lay a solid foundation for subsequent full-scale thermal testing and other advanced verification activities related to deep-thrust regulation technology.

Regarding Hardware-in-the-Loop Simulation:

Half-physical simulation originated in the aerospace field and has been developed for over 20 years, now enjoying widespread application across various industries. It involves integrating a combination of mathematical models with real-world physical equipment to create an operational simulation system. Through half-physical simulation testing, we can: 1. Avoid simulation errors arising from modeling systems that cannot be fully or accurately described by mathematical models alone, thereby addressing challenges that purely mathematical simulations cannot resolve. At the same time, it complements mathematical simulations, enabling their strengths to be more effectively utilized. 2. Enable system-level simulation testing even during the early stages of component product development, significantly reducing risks associated with integrated subsystems. This approach not only accelerates product iteration cycles but also shortens overall development timelines while mitigating development risks. For this reason, half-physical simulation has become an indispensable and critical component in control system simulation.

Principle Schematic Diagram of Semi-Physical Simulation