From Mach 0 to 6: this engine may power China’s future fighter jets and missiles

China is developing a revolutionary air-breathing engine for next-generation fighter jets and hypersonic missiles. Designed to operate continuously from a stationary start-up to over Mach 6, the “contra-rotary ramjet engine” could replace the combined turbine-ramjet systems currently used in high-speed flight. After more than three decades of work, the engine prototype has been completed and experimentally verified, marking a potential step towards engineering applications. The next steps involve adapting the engine to various aircraft platforms and conducting real-world flight tests, according to researchers involved in the project. “China’s development of new-principle engines would be a strategic choice to break the Western monopoly and even surpass the West,” Xu Jianzhong, an academician of the Chinese Academy of Sciences (CAS), was quoted as saying in a China Science Daily report earlier this month. Conventional approaches to hypersonic flight typically require two separate propulsion systems: a turbine engine for speeds below Mach 3 and a ramjet for higher speeds. This configuration results in significant “deadweight” when one system is inactive and introduces technical challenges during mode transition due to differing airflow and combustion conditions, which can cause instability, particularly during climbing or manoeuvring flight. The new design, developed by a team led by Xu, departs from conventional aero-engines by employing two sets of compressor blades rotating in opposite directions. Conventional turbine engines are generally limited to speeds below about Mach 3 – modern fighters such as the F-22 and J-20 operate at roughly Mach 2 – while ramjets cannot function at low speeds or during take-off. Xu’s contra-rotary ramjet aims to overcome these limitations by enabling operation across the full speed range without mode switching, a long-sought goal in aerospace propulsion, according to a 2025 report from a symposium held at CAS’ Institute of Engineering Thermophysics. The concept of combining turbine and ramjet technologies dates to the end of the second world war, when German engineers developed turboramjet concepts. However, those early designs used co-rotating turbine blades, which created significant material and stress challenges owing to compounded rotational forces. The key innovation in Xu’s design lies in the contra-rotary compressor, in which high- and low-pressure rotors spin in opposite directions. This configuration reduces the absolute rotational speed required for each rotor while maintaining relative speed, thereby lowering centrifugal forces on blades and discs. “The engine blades used to rotate in the same direction … Now they are rotating in opposite directions, which has improved the efficiency of rotation. When combined with stamping technology, the contra-rotary stamping engine was produced,” Xu told state broadcaster CCTV in 2023. The engine also challenges a long-standing assumption in aero-engine design that shock waves should be minimised; instead, the team harnessed them for compression. China Science Daily reported: “Their original low-entropy increase shock wave booster rotary stamping compressor eliminates the guide vanes between the high and low pressure rotors. The booster capacity of the two-stage vanes is equivalent to that of the traditional four to six-stage ones, and both the weight and size are significantly reduced.” According to the paper, Xu began focused research into hypersonic propulsion in the mid-1990s and had outlined the contra-rotary ram-compressor concept by around 2000. At the time, China was the only country among the five permanent members of the UN Security Council unable to independently develop advanced aero-engines. By 2009, the team had secured institutional support but had to build experimental platforms from scratch; nearly a decade was spent overcoming key bottlenecks in blade cascade design. The technology carries significant implications for both aircraft and missile design. For hypersonic missiles, reductions in engine weight can translate into increased fuel capacity, payload, range or manoeuvrability. A single wide-speed-range engine also simplifies integration and eliminates risks associated with propulsion mode switching. China is not alone in pursuing novel air-breathing engine concepts. In January, American giants GE Aerospace and Lockheed Martin announced they had completed tests of a liquid-fuelled rotating detonation ramjet for hypersonic missiles. The companies said that the compact engine could enable faster, longer-range flight at a lower cost while allowing ignition at lower speeds and reducing reliance on large boosters. The two approaches address similar strategic challenges through different technical pathways. Xu’s contra-rotary ramjet focuses on airflow management and compression, incorporating shock waves into the pressure-building process through a novel compressor structure. In contrast, the rotating detonation ramjet developed by US companies centres on combustion, using detonation waves to improve efficiency at supersonic and hypersonic speeds. Neither technology has yet been publicly demonstrated as a mature, widely deployable system, but their parallel development underscores intensifying competition in hypersonic propulsion. While US efforts appear to emphasise detonation-based systems for missiles, Xu’s work suggests China is pursuing a broader engine architecture that could eventually power both reusable aircraft and high-speed weapons.

From Mach 0 to 6: this engine may power China’s future fighter jets and missiles

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}Revolutionary engine prototype three decades in the making could replace combined turbine-ramjet systems in high-speed flight

Revolutionary engine prototype three decades in the making could replace combined turbine-ramjet systems in high-speed flight