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Zhong Y.,Shanghai JiaoTong University | Zhang J.-G.,Shanghai JiaoTong University | Wang D.-Z.,Shanghai JiaoTong University | Shi J.-Z.,Shanghai Automation Instrumentation Co.
Hedongli Gongcheng/Nuclear Power Engineering | Year: 2010

The Computational Fluid Dynamics (CFD) method is employed to simulate numerically the steady flow and transient flow under variable openings of the nuclear safety grade 2 single-seat pneumatic diaphragm control valve, which is a sleeve valve. The steady simulations under rated condition tells that there is a large amount of vortex in the valve seat necking and around the valve cone, which leads to a much greater flow impact on the head of the valve cone and uneven pressure distribution on spool face. More consideration should be taken on the characteristics of the valve cone accordingly, when designing a valve of this kind. Then the transient flow under 100% and 40% openings is simulated numerically on the basis of steady simulations. The pulsation of the pressure magnitude at the points with large vorticity, in the valve seat necking and around the valve cone, is monitored. The main pulsation frequencies differ from the low natural frequencies of the model, which means that it is safe from leading to structural resonance. Source


Chen J.,Shanghai University | Fu J.,Shanghai University | Bao W.,Shanghai Automation Instrumentation Co.
Communications in Computer and Information Science | Year: 2014

As wireless sensor networks are widely used in industry, the wireless monitoring system for sniffing data packets from wireless sensor networks has been realized. Many novel methods has been utilized to efficiently store data and provide reliable query and display functions in real-time listening, such as adjustment of storage structure and introduction of memory module. This paper designs and realizes a wireless monitoring and visualization system, which can accurately collect data from the communication among a variety of wireless terminal devices in real-time through changing original data storage structure, improving data query algorithms and optimizing data display algorithms. © Springer-Verlag Berlin Heidelberg 2014. Source


Deng W.,Shanghai University of Electric Power | Li K.,Queens University of Belfast | Deng J.,Queens University of Belfast | Jiang E.,Shanghai University of Electric Power | Zhu Q.,Shanghai Automation Instrumentation Co.
Communications in Computer and Information Science | Year: 2014

This paper investigates the problem of identification of a class of Hammerstein systems over a wireless network. An iterative identification method is implemented over a physical IEEE 802.11b wireless channel. Every time the identified model is used into next identification process to produce the estimated values of the plant outputs for compensating the influence of network delays. Finally the identified model can be optimized through the multiple iterations. The effectiveness of the proposed approach is demonstrated by numerical examples. © Springer-Verlag Berlin Heidelberg 2014. Source


Li F.,Shanghai University | Li F.,Henan Agricultural University | Fu J.,Shanghai University | Du D.,Shanghai University | Bao W.,Shanghai Automation Instrumentation Co.
Communications in Computer and Information Science | Year: 2014

In large scale wireless sensor and actuator network (WSAN), unreliable wireless and multihop communications make challenges in designing centralized control due to severe packet dropout and latency. To this end, distributed collaborative control (DCC) scheme based on adaptive chaos mutation particle swarm optimization (ACMPSO) is proposed. In this scheme, control task is carried out collaboratively based on hierarchical clustering using only local information. Moreover, DCC is formulated as an optimization problem, and chaos mutation is introduced to improve the optimal performance of PSO. Simulation shows that the improved PSO has better convergence property, and the proposed scheme works well to obtain control objective. © Springer-Verlag Berlin Heidelberg 2014. Source


Lai Q.,Shanghai University | Fu J.,Shanghai University | Bao W.,Shanghai Automation Instrumentation Co.
Communications in Computer and Information Science | Year: 2014

In wireless sensor networks, gateway is a hub in data transmission between wireless nodes and Personal Computer (PC). Once the gateway fails, the entire network will paralyze. To ensure the stability of the network, a methodology for the design of redundant gateway based on improved Transmission Control Protocol (TCP) congestion algorithm is proposed in this paper. In this methodology, two gateways physically connected by Ethernet are logically divided into a primary one and a secondary one. Secondary gateway is the backup of the primary gateway. The paper gives an improve method of congestion algorithm, which is applied in this scheme. It can better satisfy the high demands of real-time communication in the embedded system when compares with the traditional TCP congestion algorithm. Experiment shows the effectiveness of improved TCP congestion algorithm, when the primary gateway fails. Secondary gateway can rapidly replace the primary gateway and it ensures a better reliability of the network. © Springer-Verlag Berlin Heidelberg 2014. Source

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