Sneak Circuit Partition Analysis Algorithm Based on Network Flow Simulation

2013 ◽  
Vol 846-847 ◽  
pp. 718-723
Author(s):  
Tao Zou ◽  
Yan Zhao ◽  
Guo Qiang Zhou ◽  
Lu Lu Chen
Keyword(s):  
Adjacency Matrix ◽  
Network Flow ◽  
Engineering Application ◽  
Flow Simulation ◽  
Circuit Analysis ◽  
Analysis Time ◽  
Analysis Method ◽  
Partition Analysis ◽  
Stratified Analysis ◽  
Cutting Point

Sneak circuit analysis method is moving to intelligent and automation direction, the method based on network flow simulation has some representation. With the expansion of the circuit system topology and the increasement of the component's amount, the analysis time increases and the efficiency is difficult to be guaranteed. To solve this situation, the circuit system can be divided into some blocks for analysis. Based on the network flow simulation model, the adjacency matrix of circuit system is established. The analysis matrix of circuit system is obtained by the simplification of the adjacency matrix; use the analysis matrix as the network model for circuit system partition analysis. Select appropriate point from the network cutting point as the partition point, the circuit system can be divided into some sub-blocks by removing these points. Circuit system stratified analysis principle is proposed; determine the division method and analysis objectives of each convention level. This method can correctly analysis sneak circuit problem for circuit system, effectively reduce the analysis time and improve the analysis efficiency. It can be taken as an effective complement of sneak circuit analysis method based on network flow simulation for engineering application.

Solid-Liquid Flows Simulation for Debris Avalanche Analysis

2011 ◽  
Vol 462-463 ◽  
pp. 855-860 ◽  
Author(s):  
Takuya Toyoshi ◽  
Yoshitaka Wada ◽  
Masanori Kikuchi
Keyword(s):  
Liquid Flow ◽  
Engineering Application ◽  
Flow Simulation ◽  
Debris Avalanche ◽  
Particle Methods ◽  
Mps Method ◽  
Multi Scale ◽  
Large Particles ◽  
Liquid Flows ◽  
Solid Liquid

From a view point of engineering application, solid-liquid flow is one of the most practical phenomena, however MPS and other particle methods usually premises a constant size of all particles in the model.　In a realistic phenomenon, the size of those particles is different.　 Koshizuka et al. has proposed new algorithm for solid-liquid flow simulation which is multi-scale DEM-MPS method. The method can calculate solid -liquid flow with a large difference of the particle scale. However, its program code requires a DEM part and a MPS part, and actual phenomenon includes various scales of particles. In order to analyze solid-liquid flow with different particles, modified Laplacian model and variable cut-off radius MPS method is proposed. This modification can directly deals with small particles and large particles. Calculation cost is kept and visualization of the results has more reality by these modifications.

48″900lb Full-Welded Ball Valve Wall Thickness Optimal Design

2013 ◽  
Vol 753-755 ◽  
pp. 1826-1829
Author(s):  
Chun Li Mo ◽  
Gang Li ◽  
Yong Chen
Keyword(s):  
Stress Analysis ◽  
Wall Thickness ◽  
Oil And Gas ◽  
Engineering Application ◽  
Ball Valve ◽  
Analysis Method ◽  
Theoretical Support ◽  
Theoretical Design ◽  
Practical Engineering ◽  
Design Pressure

Fully-welded ball valve has been applied in large oil and gas pipelines, and its quality is directly related to the safety of the transportation of national energy. The wall thickness of 48900lb ball valve is greater than theoretical design thickness. In this article, FEM software was used to design minimum wall thickness using linear stress analysis method. Though changing wall thickness under design pressure, the minimum wall was 95mm which calculated by linear stress analysis method can provide theoretical support for practical engineering application.

Tunnel Seismic Prediction (TSP) and its Application in Tunnel Engineering

2014 ◽  
Vol 501-504 ◽  
pp. 1779-1782 ◽  
Author(s):  
Chun Jin Lin ◽  
Shu Cai Li
Keyword(s):  
Engineering Application ◽  
Economic Losses ◽  
Analysis Method ◽  
Tunnel Engineering ◽  
Karst Caves ◽  
Fractured Zones ◽  
Geological Prediction ◽  
Seismic Prediction ◽  
Reflection Characteristics ◽  
Insight Into

In order to avoid heavy casualties and economic losses, and to get an insight into engineering and hydrogeological conditions, Tunnel Seismic Prediction (TSP) method is applied for advanced geological prediction in tunnel engineering. Basic principle, data analysis method, prediction criterion of TSP are studied. Seismic reflection characteristics of karst caves and fractured zones are analyzed and demonstrated in Qiyueshan Tunnel. Results indicate that TSP is sensitive to karst caves and fractured zones, but may have errors in location. The location of the prediction results should be checked with comprehensive geological prediction methods. In some extent, research of the prediction principles and engineering application in the present study is instructive for further applications.

48″600lb Full-Welded Ball Valve Wall Thickness Optimal Design

2012 ◽  
Vol 190-191 ◽  
pp. 401-404
Author(s):  
Chun Li Mo ◽  
Xing Wei Tang ◽  
Xu Ming Guo
Keyword(s):  
Stress Analysis ◽  
Wall Thickness ◽  
Oil And Gas ◽  
Engineering Application ◽  
Ball Valve ◽  
Analysis Method ◽  
Theoretical Support ◽  
Theoretical Design ◽  
Practical Engineering ◽  
Design Pressure

Fully-welded ball valve has been applied in large oil and gas pipelines, and its quality is directly related to the safety of the transportation of national energy. The wall thickness of 48″600lb ball valve is greater than theoretical design thickness. In this article, FEM software was used to design minimum wall thickness using linear stress analysis method. Though changing wall thickness under design pressure, the minimum wall was 85mm which calculated by linear stress analysis method can provide theoretical support for practical engineering application

Research on Lightweight Design Manual Piston Pump

2012 ◽  
Vol 220-223 ◽  
pp. 859-862
Author(s):  
Nan Liu ◽  
Jin Li Liu ◽  
Bao Hua Fang ◽  
Hong Wang Zhang ◽  
Wei Guang Shao
Keyword(s):  
Lightweight Design ◽  
Engineering Application ◽  
Optimization Theory ◽  
Piston Pump ◽  
Analysis Method ◽  
Element Analysis ◽  
Object A ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis ◽  
Research Analysis

In this paper, as the research object a manual piston pump is designed lightweight, by using optimization theory and the finite element analysis method. The manual piston pump body, the piston and the end cover are designed proper structures include diameter, height, ayout, etc. The optimized calculation and research analysis provide credible theory and experience for engineering application.

scholarly journals Why is the subendocardium more vulnerable to ischemia? A new paradigm

2011 ◽  
Vol 300 (3) ◽  
pp. H1090-H1100 ◽  
Author(s):  
Dotan Algranati ◽  
Ghassan S. Kassab ◽  
Yoram Lanir
Keyword(s):  
Heart Rate ◽  
Network Flow ◽  
Perfusion Pressure ◽  
Compressive Loading ◽  
Flow Simulation ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
New Paradigm ◽  
Vessel Wall Thickness

Myocardial ischemia is transmurally heterogeneous where the subendocardium is at higher risk. Stenosis induces reduced perfusion pressure, blood flow redistribution away from the subendocardium, and consequent subendocardial vulnerability. We propose that the flow redistribution stems from the higher compliance of the subendocardial vasculature. This new paradigm was tested using network flow simulation based on measured coronary anatomy, vessel flow and mechanics, and myocardium-vessel interactions. Flow redistribution was quantified by the relative change in the subendocardial-to-subepicardial perfusion ratio under a 60-mmHg perfusion pressure reduction. Myocardial contraction was found to induce the following: 1) more compressive loading and subsequent lower transvascular pressure in deeper vessels, 2) consequent higher compliance of the subendocardial vasculature, and 3) substantial flow redistribution, i.e., a 20% drop in the subendocardial-to-subepicardial flow ratio under the prescribed reduction in perfusion pressure. This flow redistribution was found to occur primarily because the vessel compliance is nonlinear (pressure dependent). The observed thinner subendocardial vessel walls were predicted to induce a higher compliance of the subendocardial vasculature and greater flow redistribution. Subendocardial perfusion was predicted to improve with a reduction of either heart rate or left ventricular pressure under low perfusion pressure. In conclusion, subendocardial vulnerability to a acute reduction in perfusion pressure stems primarily from differences in vascular compliance induced by transmural differences in both extravascular loading and vessel wall thickness. Subendocardial ischemia can be improved by a reduction of heart rate and left ventricular pressure.

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