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Design and implementation of large vessel navigation system based on beidou cors

Huang P., Liu Y., Du Z., Chen Q., Chen J.

Polish Maritime Research

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2017

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S 3

12--15

EN

The ship’s pilot can obtain the ship auxiliary information through the navigation system, when berthing system can display the parameters such as traverse speed and distance of the ship. But most of the system data show that there are insufficient precision. Taking the CORS system to obtain the location information, data Calculation of Berthing System based on Polar Coordinate Algorithm, this paper puts forward a solution to the “dead point” of the berthing and aiding system, which has a certain reference value for the design of the ship berthing assistance system.

2

A numerical approach to predict the rotating stall in the vaneless diffuser of a centrifugal compressor using the eigenvalue method

Hu C., Liu P., Zhu X., Chen H., Du Z.

Journal of Theoretical and Applied Mechanics

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2017

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Vol. 55 nr 2

635--647

EN

A two-dimensional incompressible flow model is presented to study the occurrence of rotating stall in vaneless diffusers of centrifugal compressors. The diffuser considered has two parallel walls, and the undisturbed flow is assumed to be circumferentially uniform, isentropic, and to have no axial velocity. The linearized 2D Euler equations for an incompressible flow in a fixed frame of the coordinate system are considered. After discretization by a spectral collocation method based on Chebyshev-Gauss-Lobatto points, the generalized eigenvalue problem is solved through the QZ algorithm. The compressor stability is judged by the imaginary part of the eigenvalue obtained. Based on the 2D stability analysis, the influence of inflow angle, radius ratio and wave number are studied. The results from the present stability analysis are compared with some experimental measurement and Shen’s model. It is showed that diffuser instability increases rapidly and the stall rotational speed decreases quickly with an increase in the diffuser radius ratio. The largest critical inflow angle can be obtained when the wave number is around 3 ∼ 5 for the radius ratio between 1.5 to 2.2. It is also verified that the stability model proposed in this paper agrees well with experimental data and has the capability to predict the onset of rotating stall, especially for wide diffusers.

3

DFT Investigation of Reaction Mechanism of NCO with NO

Gao H. W., Du Z., Ge L. Y., Deng H. H., Yan T. X.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 4

661-668

EN

The reaction mechanism of NCO + NO was studied using density functional theory (DFT) method at 6-31G* level. Geometry optimization, vibrational frequency analysis, and kinetic and thermodynamic properties calculation were performed for reactants, transition state and products. These results indicate that the reaction branch NCO + NO rightwards arrow N2 + CO2 is a major path way of the reaction of NCO + NO on the potential energy surface.