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Lin Z.-M.,Aviation Industry Corporation of China
Advances in Manufacturing | Year: 2013

With rapid economic progress and tremendous advances of science and technology, awareness of environmental protection has become worldwide consensus. Saving energy, reducing emission and dealing with climate changes are global objectives. The aviation industry belongs to the manufacturing industry. Air transportation is a major consumer of natural resources and energy. Development of green technology in aviation manufacturing will have significant impacts on air transportation. On the basis of the international situation, this article focuses on the current development of green aviation manufacturing in China, depicting AVIC's objectives and commitments to achieving this. © 2013 Shanghai University and Springer-Verlag Berlin Heidelberg. Source

Mao J.-R.,Nanjing University of Science and Technology | Mao J.-R.,Aviation Industry Corporation of China | Choi W.-W.,Macau University of Science and Technology | Tam K.-W.,Macau University of Science and Technology | And 2 more authors.
IEEE Transactions on Microwave Theory and Techniques | Year: 2013

In this paper, a tunable bandpass filter using crossshaped multiple mode resonators (MMRs) and transformer based external quality factor tuning structures is proposed. The use of a cross-shaped MMR simplifies inter-resonators control while two tuning structures are investigated and incorporated with theMMR to implement simultaneous center frequency agility and narrow and wide bandwidth tuning. Compared with traditional tunable filters, the proposed architecture requires less tuning elements and is easier to realize wideband and high-order tunable filters. Two examples (Filter I and II) are presented to validate the design. Both filters use a single MMR and six tuning elements to achieve a third-order wideband tunable filter. Filter I reports 58% center frequency tuning with constant bandwidth and 14%-64.4% fractional bandwidth (FBW) tuning when center frequency locates at 1 GHz. Filter II achieves larger frequency agility and wider FBW tuning of 82.9% and 95%, respectively, for the same bandwidth and center frequency of Filter I. © 2013 IEEE. Source

Wang L.,Aviation Industry Corporation of China
Hangkong Dongli Xuebao/Journal of Aerospace Power | Year: 2012

Based on the three-dimensional design concept, a design method of low pressure turbine nozzle blade in wide angle diffused meridian passage was presented. The result indicates that smaller inner wall angle of divergence and bigger outer wall angle of divergence should be used to keep the flow stability near inner wall when design meridian passage, meanwhile make the vane lean to pressure side to increase the reaction near inner wall and keep the lean direction near outer wall to decrease the trend of passage vortex moving to mean radius for decreasing or eliminating the possibility of flow separation and increasing flow stability near the outer wall, and so decreasing the loss. This method has been applied and verified on a real aero-engine low pressure turbine. Source

Wang X.-Y.,Aviation Industry Corporation of China
Hangkong Dongli Xuebao/Journal of Aerospace Power | Year: 2015

Based on the concept of electromagnetic field average, the effective optical constants of mixed particles containing ellipsoidal inclusions were studied with Maxwell-Garnett effective medium theory. The effects of shape scale factors and volume fractions of inclusions on the effective optical constants of mixed particles were analyzed. The results show that: a critical value has been found in the shape scale factors of inclusion. When the shape scale factor is smaller than the critical value, the differences in the effective optical constants of mixed particles containing ellipsoidal and spherical inclusions increase with the growing shape scale factor. Otherwise, little effects are shown in the effects of shape scale factors on the effective optical constants of mixed particles. The value of effective optical constants for mixed particles varies between that for the background and inclusions. With the increase of volume fraction of inclusions, the effective optical constants of mixed particles will approach to those of inclusions. ©, 2015, BUAA Press. All right reserved. Source

Xu F.,Aviation Industry Corporation of China | Chen Z.-Z.,Shenyang Aerospace University
Gongcheng Lixue/Engineering Mechanics | Year: 2011

The fatigue crack propagation behavior of A357 casting aluminum alloys at stress ratios of 0.05 and 0.7 under T5 and T6 heat treatments were studied and crack propagation curves were modified by a crack deflection model. The research results show that the fatigue crack grows along the boundary of dendrite cells to cause a remarkable crack deflection. The fatigue crack propagation rate at r=0.05 is smaller than that at r=0.7 for both T5 and T6 heat treatments. The effect of heat treatment on the fatigue crack propagation rates cannot be seen. The fatigue crack propagation rates modified by the crack deflection model predict no change at r=0.7, while a remarkable increase of the fatigue crack propagation rates can be seen at r=0.05. It is more reasonable and accurate to use the effective stress intensity factors for Mode I and II to describe the fatigue crack propagation rates when a crack deflection occurs. Source

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