SINGLE-FIGURE RATING OF POROUS WOVEN HOSES USING A NON-LINEAR FLOW RESISTANCE MODEL

2002 ◽  
Vol 257 (2) ◽  
pp. 404-410 ◽  
Author(s):  
C.-M. PARK ◽  
J.-G. IH ◽  
Y. NAKAYAMA ◽  
S. KITAHARA
Keyword(s):  
Flow Resistance ◽  
Linear Flow ◽  
Resistance Model ◽  
Non Linear ◽  
Single Figure

A Linear Flow Resistance Model of a Multi-Governing Steam Valve System Using Computational Fluid Dynamics

2016 ◽  
Author(s):  
Peng Wang ◽  
Yingzheng Liu ◽  
Jin He ◽  
Sihua Xu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Rate ◽  
Flow Resistance ◽  
Control Strategies ◽  
Three Dimensional ◽  
Steam Flow ◽  
Linear Flow ◽  
Valve System ◽  
Resistance Model

A linear flow resistance model (LFRM) of multi-governing valve system performance was built using computational fluid dynamics to determine the distribution of flow rate through all parallel-placed steam valves at different opening ratios. A four-valve configuration connected to a water-feed pump turbine was systematically separated into three sections: valve chambers, diffuser passages and governing stages. The steam flow through each individual section was computationally modeled, and revealed that pressure drops were dependent on the flow rate. A numerical simulation strategy based on shear stress transport (SST) turbulence modeling was validated by the experimental measurements from a single valve test rig, which showed favorable agreement with the measured pressure drop at different flow rates. Subsequently, an LFRM was built to consider the geometric topology. Here, the pressure drop’s dependency on the flow rate along each section in an individual valve passage was regarded as a transfer function module. A performance map of the multi-governing valve system was obtained to predict the flow rate distribution under the opening conditions of different valves. Finally, the three-dimensional steam flow of the full multi-governing-valve system was numerically simulated to obtain the steam flow rate through different valves, and found to be in good agreement with the prediction gained using the LFRM. The proposed model can potentially be used in planning operation control strategies.

Study on the Flow Characteristics of Shengli Oilfield Super Heavy Oil

2017 ◽  
Vol 10 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Wang Shou-long ◽  
Li Ai-fen ◽  
Peng Rui-gang ◽  
Yu Miao ◽  
Fu Shuai-shi
Keyword(s):  
Pressure Drop ◽  
Pressure Gradient ◽  
Heavy Oil ◽  
Flow Characteristics ◽  
Fluid Viscosity ◽  
Linear Flow ◽  
Start Up ◽  
Non Linear ◽  
Core Permeability ◽  
Velocity Pressure

Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.

scholarly journals Linear and non-linear flow mode in Pb–Pb collisions at sNN=2.76 TeV

2017 ◽  
Vol 773 ◽  
pp. 68-80 ◽  
Author(s):  
S. Acharya ◽  
D. Adamová ◽  
J. Adolfsson ◽  
M.M. Aggarwal ◽  
G. Aglieri Rinella ◽  
...  
Keyword(s):  
Flow Mode ◽  
Linear Flow ◽  
Non Linear

scholarly journals Multi-Scale Insights on the Threshold Pressure Gradient in Low-Permeability Porous Media

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 364 ◽  
Author(s):  
Huimin Wang ◽  
Jianguo Wang ◽  
Xiaolin Wang ◽  
Andrew Chan
Keyword(s):  
Porous Media ◽  
Pressure Gradient ◽  
Water Saturation ◽  
Flow Behavior ◽  
Low Permeability ◽  
Threshold Pressure ◽  
Threshold Pressure Gradient ◽  
Linear Flow ◽  
Multi Scale ◽  
Non Linear

Low-permeability porous medium usually has asymmetric distributions of pore sizes and pore-throat tortuosity, thus has a non-linear flow behavior with an initial pressure gradient observed in experiments. A threshold pressure gradient (TPG) has been proposed as a crucial parameter to describe this non-linear flow behavior. However, the determination of this TPG is still unclear. This study provides multi-scale insights on the TPG in low-permeability porous media. First, a semi-empirical formula of TPG was proposed based on a macroscopic relationship with permeability, water saturation, and pore pressure, and verified by three sets of experimental data. Second, a fractal model of capillary tubes was developed to link this TPG formula with structural parameters of porous media (pore-size distribution fractal dimension and tortuosity fractal dimension), residual water saturation, and capillary pressure. The effect of pore structure complexity on the TPG is explicitly derived. It is found that the effects of water saturation and pore pressure on the TPG follow an exponential function and the TPG is a linear function of yield stress. These effects are also spatially asymmetric. Complex pore structures significantly affect the TPG only in the range of low porosity, but water saturation and yield stress have effects on a wider range of porosity. These results are meaningful to the understanding of non-linear flow mechanism in low-permeability reservoirs.

Conservation Law of Energy Using Fractional Taylor Series

2016 ◽  
Vol 841 ◽  
pp. 105-109
Author(s):  
Ali Soroush ◽  
Farzam Farahmand
Keyword(s):  
Taylor Series ◽  
Conservation Law ◽  
Control Volume ◽  
Fractional Differentiation ◽  
Linear Flow ◽  
First Order ◽  
Taylor Series Approximation ◽  
Series Approximation ◽  
Non Linear ◽  
Flow Power

Customary conservation law of energy is commonly derived using first-order Taylor series, which is only valid for situation of linear changes in the flow of energy in control volume. It is shown that using high-order Taylor series will approximate non-linear changes in the flow of energy but in fact some error remains. We used fractional Taylor series which exactly represent non-linear flow of energy in control volume. By replacing the customary integer-order Taylor series approximation with the fractional-order Taylor series approximation, limitation of the linear flow of energy in the control volume and the restriction that the control volume must be infinitesimal is omitted. The innovation of this paper is we show that as long as the order of fractional differentiation is equal with flow power-law, the fractional conservation law of energy will be exact and it can be used for fluid in a porous medium.

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