Dependence of the dynamic moduli of heterogeneous nematic polymers on planar anchoring relative to flow direction

2011 ◽  
Vol 50 (9-10) ◽  
pp. 767-778 ◽  
Author(s):  
Eric P. Choate ◽  
M. Gregory Forest
Keyword(s):  
Flow Direction ◽  
Dynamic Moduli ◽  
Nematic Polymers

Roll cells and disclinations in sheared nematic polymers

2001 ◽  
Vol 449 ◽  
pp. 179-200 ◽  
Author(s):  
J. J. FENG ◽  
J. TAO ◽  
L. G. LEAL
Keyword(s):  
Shear Rate ◽  
Shear Flow ◽  
Simple Shear ◽  
Flow Direction ◽  
Flow Regimes ◽  
Flow Conditions ◽  
Break Up ◽  
Nematic Polymers ◽  
Defect Nucleation

We use the Leslie–Ericksen theory to simulate the shear flow of tumbling nematic polymers. The objectives are to explore the onset and evolution of the roll-cell instability and to uncover the flow scenario leading to the nucleation of disclinations. With increasing shear rate, four flow regimes are observed: stable simple shear, steady roll cells, oscillating roll cells and irregular patterns with disclinations. In the last regime, roll cells break up into an irregular and uctuating pattern of eddies. The director is swept into the flow direction in formations called ‘ridges’, which under favourable flow conditions split to form pairs of ± 1 disclinations with non-singular cores. The four regimes are generally consistent with experimental observations, but the mechanism for defect nucleation remains to be verified by more detailed measurements.

Effects of Director Angle Anchoring Conditions on the Dynamic Moduli of Heterogeneous Nematic Polymers

2008 ◽  
Author(s):  
Eric P. Choate ◽  
M. Gregory Forest ◽  
Zhenlu Cui ◽  
Lili Ju ◽  
Albert Co ◽  
...  
Keyword(s):  
Dynamic Moduli ◽  
Nematic Polymers

Effects of strong anchoring on the dynamic moduli of heterogeneous nematic polymers

2008 ◽  
Vol 47 (2) ◽  
pp. 223-236 ◽  
Author(s):  
Eric P. Choate ◽  
Zhenlu Cui ◽  
M. Gregory Forest
Keyword(s):  
Dynamic Moduli ◽  
Nematic Polymers ◽  
Strong Anchoring

Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system

2011 ◽  
Vol 2 (1) ◽  
pp. 13-17
Author(s):  
I. David ◽  
M. Visescu
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Geothermal Energy ◽  
Flow Direction ◽  
Energy Resource ◽  
Hot Water ◽  
Injection Well ◽  
Production Well ◽  
Ground Water Flow ◽  
The Earth

Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

EFFECT OF GAS FLOW DIRECTION ON PASSIVE SUBSEA COOLER EFFECTIVENESS

2019 ◽  
Vol 11 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
Nikolay Ivanov ◽  
Vladimir V. Ris ◽  
Nikolay A. Tschur ◽  
Marina Zasimova
Keyword(s):  
Gas Flow ◽  
Flow Direction

Spatial Variability of Physical Parameters and Processes in Two Field Soils

1991 ◽  
Vol 22 (5) ◽  
pp. 327-340 ◽  
Author(s):  
K. Høgh Jensen ◽  
J. C. Refsgaard
Keyword(s):  
Transport Model ◽  
Flow Direction ◽  
Measurement Data ◽  
Flow Simulation ◽  
Solute Concentration ◽  
Conclusive Evidence ◽  
Physical Parameters ◽  
Effective Parameters ◽  
The Mean ◽  
Tracer Experiments

A numerical analysis of solute transport in two spatially heterogeneous fields is carried out assuming that the fields are composed of ensembles of one-dimensional non-interacting soil columns, each column representing a possible soil profile in statistical terms. The basis for the analysis is the flow simulation described in Part II (Jensen and Refsgaard, this issue), which serves as input to a transport model based on the convection-dispersion equation. The simulations of the average and variation in solute concentration in planes perpendicular to the flow direction are compared to measurements obtained from tracer experiments carried out at the two fields. Due to the limited amount of measurement data, it is difficult to draw conclusive evidence of the simulations, but reliable simulations are obtained of the mean behaviour within the two fields. The concept of equivalent soil properties is also tested for the transport problem in heterogeneous soils. Based on effective parameters for the retention and hydraulic conductivity functions it is possible to predict the mean transport in the two experimental fields.

Recent Patents on Valve Mechanism Device

2020 ◽  
Vol 13 (3) ◽  
pp. 230-241
Author(s):  
Ye Dai ◽  
Hui-Bing Zhang ◽  
Yun-Shan Qi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Flow Direction ◽  
Research Progress ◽  
Valve Mechanism ◽  
Advantages And Disadvantages ◽  
Valve Structure ◽  
Valve Leakage ◽  
Safety And Reliability

Background: Valves are an important part of nuclear power plants and are the control equipment used in nuclear power plants. It can change the cross-section of the passage and the flow direction of the medium and has the functions of diversion, cutoff, overflow, and the like. Due to the earthquake, the valve leaks, which will cause a major nuclear accident, endangering people's lives and safety. Objective: The purpose of this study is to synthesize the existing valve devices, summarize and analyze the advantages and disadvantages of various devices from many literatures and patents, and solve some problems of existing valves. Methods: This article summarizes various patents of nuclear-grade valve devices and recent research progress. From the valve structure device, transmission device, a detection device, and finally to the valve test, the advantages and disadvantages of the valve are comprehensively analyzed. Results: By summarizing the characteristics of a large number of valve devices, and analyzing some problems existing in the valves, the outlook for the research and design of nuclear power valves was made, and the planning of the national nuclear power strategic goals and energy security were planned. Conclusion: Valve damage can cause serious safety accidents. The most common is valve leakage. Therefore, the safety and reliability of valves must be taken seriously. By improving the transmission of the valve, the problems of complicated valve structure and high cost are solved.

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