作者: Xiao Liang Feng, Xue Jun Xu

摘要: Geographic Information Systems (GIS) are designed to support the management, manipulation, analysis, and modeling of spatial data. Water supply pipeline network is a system which has a large of spatial attribute data. In order to improve the managing and working efficiency, the paper proposed a new method for designing the long distance pipeline based on GIS. Seamless integration of GIS platform, hydraulic model of long distance pipeline is built which is base of hydraulic calculation. The model is based on building pipeline concise model dynamic. The hydraulic calculation is to guarantee the authenticity of the model which can help to simulate the whole system status and analyze the condition of long distance pipeline. The pressure and safety coefficient models of long pipeline based on GIS can help operator to know the details of every segment in the long distance pipeline system. The method locates the weakness of long distance pipeline and displayed impressively on GIS platform. All the technologies strengthen the security of the pipeline design, improve the accuracy of hydraulic calculation, and help operators to analyze the long distance pipeline condition by spatial visualization. The example shows that the method is reasonable, effective, and has been applied to practical project.

502

作者: Xiao Hui He, Lei Gao, Hong Bing Liu, Zhi Gang Li

摘要: This paper has studied the partial cavitation of 2-D hydrofoil based on the theory of viscous flow. The numerical calculation sets forth from the complete N-S equation and adopts the two-equation turbulence model closed Reynolds equation. As the basic control equation, the cavitating flow adopts the Rayleigh plesset model and calculates the zero angle of attack. At the same time, it calculates the influences of different ship speeds on the hydrofoil partial cavitating flow and analyzes the flow field of the hydrofoil. In addition, it makes comparisons on the calculation results and the published test conclusions. The results have shown that the calculation method in this paper has relatively good calculation precise degree.

102

作者: Zhan Ying Wu, Zhen Wei Mu

摘要: The unsteady flow RNG k ~ ε turbulence model and VOF Method are employed to numerically simulate 3-D flow field of diversion tunnel outlet stilling pool in Xinjiang dina river wuyi reservoir. The computational and experimental water surface elevation, pressure on the bottom and cross-sectional mean velocity of the suspended grid stilling pool are compared in well agreement. Suspended grid is used in stilling pool, the number of vortex and range are increased in the pool, and the size of the vortex is decreased along with the flow increase. The suspended grid position is determined at end of the vortex. In the suspended grid stilling pool water stability, flow regime is good.

2569

作者: Jian Wu, Yang Hua, Wei Wei Shang, Yi Bin Liu, Bin Xu

摘要: In order to build an accurate spray model for studying the characteristics of n-butanol and diesel blends. First, the calculation of gas-liquid two phase flow inside the nozzle was carried on, the birth and development of cavitation and the non-uniformity of the velocity field inside the nozzle were analysed. Then the spray model coupled flow inside the nozzle was established and verified. The spray simulation calculation of n-butanol and diesel blends was carried on by using the model, and compared the results with the results of flow inside the nozzle not coupled. The results show that the droplet speed, spray penetration and SMD of D100 and N40 is all bigger under the condition of without coupling flow inside the nozzle. The flow inside nozzle will affect the whole spray process and spray characteristics, which will ultimately affect the combustion and emission characteristics. So the spray model coupled flow inside the nozzle can provide accurate initial condition for spray calculation, which can reflects the fuel spray characteristics truly.

1684

作者: Yi Yang, Liang Chu, Di Fan, Yu Ting Huang

摘要: This paper proposes a flow calculation method of the ball solenoid valve, by measuring diameter of the input valve spool, we can estimate the rated flow of the solenoid valve. Aiming at the calculation method, we have built a MATLAB/Simulink model to calculate the valve flow, and we also validated the model by the flow demand of one type of RBS system.

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