Advanced Materials Research Vols. 610-613

Abstract: Wave function expansion method and Green function method were employed to study thescattering problem of SH-waves to the semi-cylindrical canyon and rectangular hill on the gr ound. First, the displacements in the half space and rectangular hill were given which can santisfy the stress-free conditions on the free boundaries. Then, the first kind of Fredholm integration equation of the unknown distribution stress was obtained by using the displacement conditions on the common boundary between the half-space and the rectangular hill, and Gauss-Legendre integration formula was used to solve the equation. The given example results show the feasibility and practicability of the method here.

Abstract: This study presents the investigation of aerodynamics and aeroacoustics of centrifugal fan using commercial computational fluid dynamics (CFD) code. The unsteady turbulent flow of the fan is simulated with Detached Eddy Simulation (DES) and the acoustics sources are computed based on the pressure fluctuations. The Ffowcs Williams and Hawking model is used to predict the tonal noises in aeroacoustics simulation.

Abstract: Through analysis of the vibration characteristics of 1000mm² Large Section Conductor and test on the Anti-vibration effect of the vibration damper, a kind of method to determine the installation location of the vibration damper for 1000mm² large Section Conductor by Simulation test is put forward. Compared with the conventional method, the protected span of the damper which installation location is determined by the new method is larger. This method will have guiding significance for the anti-vibration of the large section conductor.

Abstract: Partial coherence analysis can eliminate competing influences of different noise sources and identify the main noise source when all noise sources of system are relevant. In the paper, the method of partial coherence analysis is used for identifying noise source of grader. A multi-input and multi-output noise source identification model is established. And then the computational formula is developed. Finally, an experiment is carried out with an actual grader. In the experiment the main noise sources are accurately identified.

Abstract: Floating floor coverings are widely applied in ship structures. With regard to the laminated composite shells made up of floating floor coverings and cabin deck and based on ANSYS system, a dynamics analysis on structures of three different kinds of floating floors is performed using FEM built upon laminated shell elements. The influence of rockwool board in terms of thickness, density and elastic modulus on structure dynamic characteristics is discussed. The performances of vibration control of three different floating floor structures are compared. The FEM performs well in analyzing and calculating the vibration control characteristics of structures, the results of which offer certain reference to the design and research on cabin deck covered with floating floor coverings.

Abstract: Airport noise is noise pollution produced by any aircraft or its components, during various phases of a flight,especially the landing phases. This paper study the airport noise prediction model basing on WECPNL(Weighted Equivalent Continuous Perceive Noise Level) recommended by ICAO as a index. With the measurement data,which is properly distribute to the final of active runway and centerline, a brief summary of WECPNL-based prediction model from touchdown to runway centerline is established. However, the results showed a discrepancy of certain points was between prediction and measurement data, especially 1.5-2.5km away from the airport. Therefore, an amendment was proposed with greater accuracy, which the relative of the new model for future prediction ranged from 1.0% to 2.0%. To some extent, this model also can reflect and make full use of the limited data with a high accuracy, especially suit for monitoring rapidly in some new small airports.

Abstract: In order to solve the problems of multifactor and fuzziness of airport noise environmental impact, the multilevel fuzzy cluster analysis for comprehensive assessment of airport noise environmental impact was proposed in this paper. The method is a quantitative analysis of the environmental impact of airport noise, which integrates Fuzzy Cluster Analysis with Analytic Hierarchy Process (AHP). The results show that the method is better reflecting of fuzziness between the levels of noise environmental pollution, better solving the problem of weight factors of various indicators, and making assessment results more reasonable. This work can provide decision support for airport noise manager.

Abstract: The vibration energy can be converted to electrical energy directly and efficiently using piezoelectric cantilever beam based on piezoelectric effect. Since its structure is simple and its working process is unpoisonous to the environment, the piezoelectric cantilever beam can be used in various fields comprehensively. The present paper perform an analysis on the vibration energy harvesting problem of piezoelectric bimorph cantilever beam. The piezoelectric cantilever model has been formulated using the theory of elasticity mechanics and piezoelectric theory. A prototype of piezoelectric power generator is set up to do vibration test, and the electromechanical coupling FEA model under vibration load is built to simulate its output displacement, stress and voltage. The present numerical results of piezoelectric bimorph cantilever coincide well with our related experimental results, which shows the validity of the present FEA model and the relate results.

Abstract: According to the requirements of the circulating water treatment, a corrosion and scale inhibitor which compounded several single corrosion inhibitor and scale inhibitor was prepared, resulting in simplifying the process of operation, improving the concentration ratio of circulating water from 2.2 to 2.8, reducing the sewage volume, and decreasing the corrosion rate and cohesion rate. Therefore, the economic efficiency of the power plant gets greatly improved.

Abstract: By the methods of system dynamics, a model prediction of the potential of cleaner production (PCP) in Liao River Basin was constructed, and the dynamic trend of PCP in Liao River Basin was simulated by using this model. It was predicted that under the conditions of maintaining present development schemes, the CPC in Liao River Basin in 2000-2020 would be increased year by year. The result showed that selected 2007 as the base year, with the cleaner production, the emission of COD and NH3-N would be reduced 10.7% and 13.6% respectively in 2010. The emissions of these would be reduced 26.6% and 35.0% in 2015, 40.5% and 54.6% in 2020. Cleaner production had obvious effect on water saving and emission reduction in Liao River Basin.