Chinese Aero Engines - Recent Developments
China's aviation industrial base, with the strong support of the Chinese government, has improved substantially since the dawn of the new century. China is capable of developing and producing both advanced commercial and military aircraft and seeks to compete with foreign aviation manufacturing companies in the near future. Despite these advances, however, the industry continues to experience some problems, most notably in producing advanced engines.
China has been unable to reproduce Russia's highly efficient high-temperature turbofan AL-31F engine, designed in the early 1980s and currently mounted on the Su-27 fighter and its modifications. The engines for Sukhoi planes manufactured in China are made in Russia and then assembled and adjusted in China. The AL-31F engine is also mounted on China's J-10 fighter planes. The engine's Chinese analogue, the WS-10, is less efficient than the Russian prototype. China's JF-17 Thunder fighters need the RD-93 engines produced at the Moscow-based Chernyshev machine-building plant. It was reported in 2002 that China had imported 240 D-30 KP-2 engines from Russia to use in upgrading its H-6K bombers. The H-6K project stopped because of the suspension of the contract for 240 D-30KP2. J-10 and H-6K production were only restarted after China started to purchase engines from the Russians again.
Despite progress in other areas of aviation, China's aviation engine sector remains an ''Achilles' heel'' in China's aviation manufacturing industry. A major obstacle is China's inability to successfully develop and manufacture an advanced turbofan engine. China is not alone in experiencing difficulties producing a turbofan engine. Currently, only a few nations have mastered the techniques necessary to manufacture a turbofan engine. Besides the United States, other countries that can independently manufacture turbofan engines include France, Russia, Ukraine, and the United Kingdom.
The great successes of the nuclear weapon and ballistic missile programs in the early 1960s led China to overrate her technological abilities. Many decision-makers, supervisors and implementers in the Chinese aviation industry lacked preparation for the difficulties of of aircraft engine design and production. China's aviation industry plans were unprofessional, and lacked a solid industrial foundation and basic scientific research. Prior to the 1980s, the aviation industries were shaken by political movements, such as the Great Leap Forward and the Cultural Revolution. After 1980, they were negatively impacted by reductions in military expenditures. All these factors combined in a single result: after 40 years, China in the 1980s was still unable to independently develop a new aircraft engine.
The Rand Corporation noted in 2005 that China had eight aircraft engine manufacturers. The most important manufacturers were Liming, which made turbojets for the J-5, J-6, J-7, and J-8 fighters and the Q-5 attack aircraft, and is now developing the WS-10 turbofan; Xi'an, which makes the WP-8 engine for the H- 6 medium bomber; Liyang, which currently makes turbojets for the J-7 and J-8 fighters; and China National South Aeroengine Company, which makes turboprops for the Y-8 medium transport and turboshafts for the Z-9 helicopter. Chengdu, Harbin, Shanghai, and Changzhou do not appear to be currently involved in whole-engine production.
The aero piston-type engine is the machinery that applies the mixture of gasoline and air, burns in closed vessel (cylinder) and makes power in expansion. The piston-type engine must drive the screw propeller, which generates pushing (pulling) force and is suitable for middle and low flying middle and small-sized planes. Turboprop engine, also called propeller engine, is composed of propeller and gas generator and the propeller is driven by turbine. The propeller is of about 1000 rotations per minute due to its big propeller and rotation speed lower than the turbine. In order to make the turbine and propeller work in normal range, it is necessary to install a speed reducer between them and to reduce the rotation speed of turbine to one tenth, only in this way, the propeller can be driven. The speed reducer is of heavy load, complicated structure and high manufacturing cost and its weight is equal to the total weight of air compressor and turbine. As part of the whole engine, the speed reducer takes important place in design, manufacturing and test.
According to Rand, China's engine manufacturers are apparently able to produce satisfactory turboprop engines, including the 4,192-shaft-horsepower China National South Aeroengine Company WJ6A used in the Y-8 medium transport. However, the Y-12 light transport and the new MA60 airliner (based on the Y-7) use engines manufactured by Pratt & Whitney Canada (P&WC), presumably because these engines are more efficient or reliable than Chinese-made turboprops. P&WC engines are also reportedly being considered for an upgraded version of the Y-8.
The turboshaft engines for the Z-8 helicopter were produced by the Changzhou Lanxiang Machinery Works. The Z-9 and Z-11 use license-produced Turbomeca Arriel engines produced by South Aeroengine, and P&WC engines have been selected to power the developmental Z-10.43 In addition, Chinese enterprises produce components for all three major Western engine manufacturers: General Electric, Rolls-Royce, and Pratt & Whitney.
More efficient and more powerful than turbojet engines, turbofan engines are a necessary component of any modern commercial or military jet. A turbofan engine is the most modern variation of the basic gas turbine engine. In the turbofan engine, the core engine is surrounded by a fan in the front and an additional turbine at the rear. This sort of construction allows a turbofan engine to provide significantly more thrust per fuel amount than a normal gas turbine engine. Without the ability to successfully produce a turbofan engine, China will remain dependent on imported engines. Presently, China is attempting to establish its independence from foreign engine suppliers by developing its own turbofan engines, such as the WS-10A and the SF-A turbofan engines.
In 2010, AVIC Commercial Aircraft Engine Co., Ltd started to construct its R&D base. The launch of the large aircraft engine development project marked the formal start of China's civil engines. Following the United States, Britain, Russia and France, China has become the world's fifth country committed to the independent R&D of aeroengines. With the increasingly powerful economic strength, China has paid more attention to the aeroengine industry and provided support policies. Xi'an Aero-Engine has huge potential. It can integrate the engine assets of Shenyang Liming Aero-engine, Harbin Dongan Engine and Chengdu Engine. By product, Shenyang Liming is the most promising enterprise.
In order to improve China's aviation industrial base, Beijing has implemented an industrial strategy for its aviation industry. Three factors in particular help to promote China's aviation manufacturing industry. First, China's aviation industry enjoys strong government support. Second, the industry benefits from an offset policy that requires technology and know-how transfers from more-established foreign aviation manufacturing firms in return for market access in China. Third, the close integration between the commercial and military sectors of China's aviation industry allows Beijing to bolster its military aviation manufacturing capabilities by exploiting advances in the commercial aviation sector.
Technology and processes perfected in China's commercial aviation industry will strengthen China's military aviation industry. This in turn will increase China's air combat capability and contribute to China's capacity to hinder the U.S. military's ability to operate freely in East Asia.
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