From Import Dependence to Independent Innovation: The Localization Path of Marine Propeller Design and Manufacturing

Strategic Significance of Autonomous Marine Propeller Design and Manufacturing

The shipbuilding industry is a core pillar of the national maritime power strategy, and as a key component of ship propulsion systems, the design and manufacturing capability of marine propellers directly determines ship power performance, energy efficiency, and navigation safety. For a long time, the global high-end marine propeller market has been dominated by a few European and American companies, with critical design technologies and manufacturing processes subject to strict restrictions. As a result, domestic large-scale shipbuilding enterprises had to rely on imported products, facing high procurement costs, long delivery cycles, and inadequate maintenance services, which seriously constrained the independent development of China’s shipbuilding industry.

With the continuous improvement of global shipping requirements for energy efficiency and environmental protection, as well as the rapid expansion of China’s high-end shipbuilding capacity, including ultra-large container ships, very large crude carriers (VLCCs), and liquefied natural gas (LNG) carriers, the strategic urgency of achieving independent marine propeller design and manufacturing has become increasingly prominent. On the one hand, an autonomous and controllable propeller supply chain can effectively reduce shipbuilding costs and enhance the competitiveness of Chinese shipyards in the international market. On the other hand, breaking through technological barriers and mastering independent intellectual property rights in propeller design and manufacturing represent a key step in transforming China from a major shipbuilding country into a world-leading shipbuilding power.

Taking the 307,000-ton very large crude carrier Junwang, delivered in March 2026, as an example, the vessel was independently designed and built by Dalian Shipbuilding Industry Co., Ltd. under China State Shipbuilding Corporation. The project team completed an integrated optimization of a high-efficiency propeller, pre-swirl energy-saving device, and vortex-reducing fin. The comprehensive energy-saving performance reached world-class levels, reducing annual fuel costs by approximately 35 million RMB. This case demonstrates that independently designed and manufactured high-performance propellers can not only meet the propulsion requirements of ultra-large vessels but also generate significant economic and environmental benefits through technological innovation, highlighting the core value of propeller autonomy in industrial upgrading.

Key Technical Challenges in Marine Propeller Design

Marine propeller design is a complex multidisciplinary engineering system involving fluid dynamics, structural mechanics, materials science, and acoustics. Its primary objective is to achieve maximum propulsion efficiency, minimum vibration and noise, and optimal energy-saving performance while satisfying strength requirements. This process involves numerous technical challenges.

The first challenge is hydrodynamic performance optimization. Marine propellers operate in complex flow environments, where interactions occur between the hull, propeller, and individual blades. Optimizing blade geometry, expanded area ratio, pitch distribution, and other parameters to maximize propulsion efficiency is a fundamental challenge during the design stage. Traditional design methods rely heavily on empirical formulas and model tests, resulting in long development cycles, high costs, and limited optimization capabilities. With the development of computational fluid dynamics (CFD), numerical simulation has become a major tool for propeller hydrodynamic design. However, accurately predicting turbulence, cavitation phenomena, and hull–propeller interaction in complex flow fields still requires advanced computational models and significant computing resources.

The second challenge is structural strength and vibration/noise control. During operation, propellers experience alternating hydrodynamic loads, which may cause fatigue damage over long periods. Under extreme conditions such as emergency stopping or severe sea states, blade roots experience substantial stresses, imposing strict requirements on structural design. Meanwhile, propeller-induced vibration and noise not only affect passenger comfort but also increase underwater radiated noise, potentially impacting marine ecosystems. Therefore, design optimization is required to reduce excitation forces and control noise levels.

The third challenge involves integrated design with energy-saving devices. In recent years, as the International Maritime Organization (IMO) has introduced stricter ship energy-efficiency requirements, optimizing the propeller alone is no longer sufficient. Propellers must be integrated with pre-swirl ducts, vortex-reducing fins, and other energy-saving devices to improve inflow conditions and reduce wake losses. Such integrated optimization requires consideration of complex flow interactions among multiple components, significantly increasing design complexity. In the Junwang project, the design team achieved excellent energy-saving performance by integrating the high-efficiency propeller with energy-saving devices, demonstrating the value of integrated design approaches.

Development History and Challenges of Marine Propeller Manufacturing

Marine propeller manufacturing has evolved from traditional sand casting to precision casting and from metallic materials to composite materials. Different development stages have faced different technical challenges. Traditional marine propellers are mainly manufactured using copper alloy casting, a technology developed over more than a century. Although mature and reliable, this approach suffers from long production cycles, low material utilization efficiency, heavy weight, and difficulties in producing complex curved structures.

For ultra-large marine propellers, individual blades may weigh tens of tons due to their enormous size. Large-scale casting requires extremely high standards for equipment and process control, while defects such as porosity and shrinkage are difficult to eliminate, resulting in high manufacturing challenges. In recent years, advances in precision casting have enabled domestic enterprises to manufacture ultra-large propellers exceeding 10 meters in diameter, meeting the requirements of ultra-large container ships and crude carriers. However, differences remain compared with international leaders in high-precision manufacturing of complex curved surfaces.

Biomimetic tubercle propellers represent a new type of innovative design inspired by the flow-control mechanism of humpback whale flippers. By introducing tubercle structures along blade edges, these propellers can delay cavitation, reduce noise, and improve efficiency. However, the highly complex curved structures of these blades are difficult to manufacture accurately using traditional casting methods. Although additive manufacturing technologies can produce complex geometries, industrial-scale 3D printing of large propellers remains expensive and slow, currently limiting applications mainly to prototypes and small-batch production.

Composite propellers are considered an important future development direction. Compared with traditional metal propellers, composites offer advantages including low density, high specific strength, excellent fatigue resistance, and greater design flexibility. They enable adaptive pitch adjustment under different operating conditions, improving propulsion efficiency. However, manufacturing composite propellers involves complex processes such as fiber placement and resin molding, requiring precise control of fiber orientation, volume fraction, and manufacturing defects to ensure structural strength and dimensional accuracy.

Current Status and Breakthroughs in China’s Autonomous Marine Propeller Design and Manufacturing

In recent years, supported by national policies promoting shipbuilding transformation and upgrading, China’s shipbuilding industry has conducted extensive research on autonomous marine propeller design and manufacturing. Significant progress has been achieved in design technology, manufacturing processes, and testing validation. China has developed independent capabilities covering a wide range of marine propeller types, gradually breaking the long-standing dependence on foreign technologies.

In terms of design technology, domestic research institutes and major shipbuilding enterprises have developed proprietary marine propeller hydrodynamic design software. Combined with CFD simulations and model testing, these tools can support the integrated design of various propellers and energy-saving devices. For major ship types such as VLCCs and ultra-large container ships, domestically designed propellers have achieved internationally competitive propulsion efficiency and energy-saving performance.

In manufacturing capability, China has established several large-scale professional propeller production bases capable of manufacturing ultra-large propellers with diameters exceeding 12 meters. Casting technologies have evolved from conventional sand casting to precision casting, improving defect control and product reliability. Domestic machining and inspection equipment can now achieve high-precision processing and three-dimensional measurement of large propellers.

Regarding materials, traditional copper alloy propeller materials have achieved domestic production with stable supply and reliable performance. Meanwhile, China is actively developing composite propellers, making progress in resin matrices, reinforcing fibers, and manufacturing processes. Prototype composite propellers have been produced and tested, accumulating valuable engineering experience.

Nevertheless, some gaps remain in high-end applications, including large-scale engineering applications of advanced composite propellers and specialized propellers for large cruise ships. Further technological breakthroughs are still required.

Industrial Transformation Opportunities Brought by Composite Materials

The development of composite materials is driving profound changes in the marine propeller industry, providing new opportunities for performance improvement while creating new requirements for autonomous design and manufacturing.

The most significant advantage of composite propellers is lightweight design. Carbon fiber composites have a density approximately one-fifth that of copper alloys. Under equivalent strength conditions, composite propellers can reduce weight by more than half. This reduces ship displacement, structural loads, and propulsion system weight. In addition, composite materials provide excellent fatigue resistance, extending service life and reducing maintenance costs.

More importantly, the design flexibility of composites provides greater opportunities for propeller optimization. By adjusting fiber orientations, composite blades can achieve tailored flexibility, allowing adaptive deformation under different operating conditions and maintaining optimal propulsion efficiency. Research from the EU CoPropel project indicates that adaptive composite propellers can improve average propulsion efficiency by approximately 8% compared with conventional metal propellers.

Composite materials also facilitate the manufacturing of complex curved structures, providing a foundation for innovative designs such as biomimetic propellers. Furthermore, composite propellers can integrate structural health monitoring systems using embedded fiber-optic sensors to monitor stress, strain, and damage conditions in real time, improving operational safety and reducing maintenance costs.

Despite challenges such as high material costs, complex manufacturing processes, and incomplete certification standards, continuous technological progress and industrial development are expected to accelerate the adoption of composite propellers.

Future Development Directions of Autonomous Marine Propeller Design and Manufacturing

Looking ahead, marine propeller design and manufacturing will develop toward higher efficiency, environmental sustainability, and intelligent production.

First, improving energy efficiency will remain a major focus to meet increasingly strict environmental regulations. Future propeller development will involve deeper integration with ship hulls, engines, and energy-saving devices, while adopting greener manufacturing processes to reduce carbon emissions.

Second, composite propeller technology will be further advanced toward engineering applications. China needs to strengthen research on low-cost, high-precision manufacturing technologies, improve design methodologies and testing systems, and establish internationally recognized certification standards.

Third, intelligent manufacturing technologies will play an increasingly important role. Digital design platforms will integrate design, simulation, manufacturing, and inspection processes, improving efficiency and shortening development cycles. Industrial robots, additive manufacturing, digital inspection, artificial intelligence, and big data technologies will further enhance manufacturing precision and optimization capabilities.

Fourth, fundamental research and innovative designs should continue to be strengthened. Concepts such as biomimetic tubercle propellers require further investigation into optimal parameters and manufacturing methods to achieve practical engineering applications. Collaboration among universities, research institutes, and enterprises will accelerate technological breakthroughs.

Conclusion

After years of technological development, China has achieved a transition from initial exploration to independent capability in marine propeller design and manufacturing. The country now possesses autonomous supply capabilities for major ship types. However, achieving global leadership and full technological independence still requires continuous innovation.

Driven by the maritime power strategy and industrial upgrading, the integration of advanced technologies such as composite materials, artificial intelligence, and intelligent manufacturing will enable China’s marine propeller industry to achieve further breakthroughs. These developments will provide strong support for the high-quality growth of China’s shipbuilding industry and enhance its competitiveness in the global market.

Keywords:
Marine propeller, autonomous design, manufacturing, localization, hydrodynamic optimization, composite materials, intelligent manufacturing, energy efficiency, shipbuilding industry, technological breakthrough, CFD simulation, integrated design, lightweight, biomimetic propeller, sustainable development, digital manufacturing, innovation, propulsion system, engineering application, marine technology.