scholarly journals Influence of Fracture Roughness on Aperture Fracture Surface and in Fluid Flow on Coarse-Grained Marble, Experimental Results

2014 ◽  
Vol 02 (05) ◽  
pp. 59-67 ◽  
Author(s):  
G. Dimadis ◽  
A. Dimadi ◽  
I. Bacasis
Keyword(s):  
Fluid Flow ◽  
Fracture Surface ◽  
Experimental Results ◽  
Coarse Grained ◽  
Fracture Roughness

scholarly journals A Simplified Model Applied to the Barite Sag and Fluid Flow in Drilling Muds: Simulation and Experimental Results

2017 ◽  
Vol 72 (4) ◽  
pp. 23 ◽  
Author(s):  
José Messias Ribeiro ◽  
Felipe Moreira Eler ◽  
André Leibson Martins ◽  
Cláudia Miriam Scheid ◽  
Luís Américo Calçada ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Experimental Results ◽  
Simplified Model ◽  
Drilling Muds

An Experimental Investigation for Flow Past a Circular Cylinder With Rectangular Strips

2002 ◽  
Author(s):  
Chuan He ◽  
Tianyu Long ◽  
Mingdao Xin ◽  
Benjamin T. F. Chung
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Circular Cylinder ◽  
Drag Coefficient ◽  
Experimental Results ◽  
Sharp Edge ◽  
Flow Past ◽  
Rectangular Strips

This paper reports an experimental investigation for fluid flow past a circular cylinder with two small rectangular strips and single sharp-edge strips on its surface. The experimental results reflected that different arrangements or dimensions of the strips produced significantly different effects on the flow. The forward step caused a stronger disturbance with a small increase in drag. The backward step arrangement softened the disturbance but reduced the drag coefficient by 33%.

Temperature Distribution in a Turbulent Flow in the Heat Pollution Phenomena

2020 ◽  
Author(s):  
Victorita Radulescu
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Fluid Flow ◽  
Temperature Distribution ◽  
Prandtl Number ◽  
Experimental Results ◽  
Turbulent Heat ◽  
Fluid Viscosity ◽  
Solid Walls ◽  
Good Agreement

Abstract The thermal pollution, with major effects on the water quality degradation by any process involving the temperature transfer, represents nowadays a major concern for the entire scientific world. The turbulent heat and the mass transfer have an essential role in the processes of thermal pollution, mainly in problems associated with the transport of hot fluids in long heating pipes, thermal flows associated with big thermo-electric power plants, etc. In the last decades, the problems of the turbulent heat and mass transfer were analyzed for different dedicated applications. The present paper, in the first part, estimates the universal law of the velocity distribution near a solid wall, with a specific interpretation of the fluid viscosity, valid for all types of flows. Most of the scientific researches associate nowadays both the turbulent heat and the mass transfer with the Prandtl number. In the turbulent fluid flow near a solid and rigid surface, there are three flowing domains, laminar, transient, and fully turbulent, each one with its characteristics. In this paper, it is assumed that the friction effort at the wall remains valid at any distance from the wall, but with different forms associated with the dynamic viscosity. By using the superposition of the molecular and turbulent viscosity and by creating the interdependence between the molecular and turbulent transfer coefficients is estimated the mathematical model of the velocity profile for the fluid flow and temperature distribution. Three supplementary hypotheses have been assumed to estimate the dependence between the laminar and thermal sub-layer and the hydrodynamic sub-layer. The theoretical obtained distribution was compared with some experimental results from the literature and it was observed there is a good agreement between them; the differences are smaller than 3%. In the second part of the paper is determined the temperature field for a fluid flowing also in presence of the solid surfaces with different temperatures, associated not only with the Prandtl number but also with the fluid viscosity and its dependence with the temperature, correlated with the Grashoff number. In the next paragraph is used the concept of the laminar substrate with different thicknesses for the hydrodynamic flows with thermal transfer to the solid walls, and also the inverse transfer from the solid walls affecting the fluid flow and the mass transfer. The obtained mathematical model is correlated with the semi-empirical data from the literature. By numerical modeling, the obtained results were compared with the experimental measurements and it was determined the dependence between the Stanton number and the Prandtl number. The numerical results demonstrate a good agreement with the experimental results in a wide range of the Prandtl numbers from 0.5 to 3000. Finally, are mentioned some conclusions and references.

Fluid Flow Through Randomly Packed Monodisperse Fibers: The Kozeny-Carman Parameter Analysis

1997 ◽  
Vol 119 (1) ◽  
pp. 188-192 ◽  
Author(s):  
O. Rahli ◽  
L. Tadrist ◽  
M. Miscevic ◽  
R. Santini
Keyword(s):  
Fluid Flow ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Experimental Results ◽  
Parameter Analysis ◽  
Flow Through Porous Media ◽  
Aspect Ratios ◽  
A Value ◽  
Flow Through ◽  
Permeability Increase

Experimental studies have been carried out on fluid flow through porous media made up of randomly packed monodisperse fibers. The permeability and the Kozeny-Carman parameter kk are deduced from experimental results. The variations of the permeability increase exponentially with the porosity. The parameter kk is a decreasing function of the porosity ε and tends asymptotically to a value close to that deduced from a modified Ergun relation. The important decrease, observed for small aspect ratios, is certainly an effect of the cut sections of fibers. The results in terms of parameter kk are systematically compared to those deduced from various theoretical models. The variation laws of the parameter kk, deduced from different models, present important discrepancies with our experimental results.

scholarly journals Computer Modeling of Electromagnetic Fields and Fluid Flows for Edge Containment in Continuous Casting

2004 ◽  
Vol 127 (4) ◽  
pp. 724-730 ◽  
Author(s):  
Fon-Chieh Chang ◽  
John R. Hull
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Liquid Metal ◽  
Eddy Currents ◽  
Stokes Equations ◽  
Fluid Flows ◽  
Experimental Results ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel (Ispat Industries Ltd.) for twin-roll casting. This mathematical model can greatly shorten casting research on the use of EM fields for liquid metal containment and control. It can also optimize the existing casting processes and minimize expensive, time-consuming full-scale testing. The model was verified by comparing predictions with experimental results of liquid metal containment and fluid flow in EM edge dams designed at Inland Steel (Ispat Industries Ltd.) for twin-roll casting. Numerical simulation was performed by coupling a three-dimensional (3D) finite-element EM code (ELEKTRA) and a 3D finite-difference fluids code (CaPS-EM) to solve Maxwell’s equations, Ohm’s law, Navier-Stokes equations, and transport equations of turbulence flow in a casting process that uses EM fields. ELEKTRA is able to predict the eddy-current distribution and EM forces in complex geometry. CaPS-EM is capable of modeling fluid flows with free surfaces and dynamic rollers. The computed 3D magnetic fields and induced eddy currents in ELEKTRA are used as input to flow-field computations in CaPS-EM. Results of the numerical simulation compared well with measurements obtained from both static and dynamic tests.

scholarly journals Thrust Faults Promoted Hydrocarbon Leakage at the Compressional Zone of Fine-Grained Mass-Transport Deposits

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiliang Sun ◽  
Xinong Xie ◽  
Shiguo Wu ◽  
Guorui Yin
Keyword(s):  
Fluid Flow ◽  
Mass Transport ◽  
Northern South China Sea ◽  
Coarse Grained ◽  
Thrust Faults ◽  
Borehole Data ◽  
Fine Grained ◽  
Hydrocarbon Reservoir ◽  
Effective Seal ◽  
Mass Transport Deposits

Fine-grained mass-transport deposits (MTDs), especially their compressional toe zones, are traditionally considered as effective seal in constraining the vertical fluid migration underneath. However, this study documents thrust faults at the compressional toe zone of fine-grained MTDs that could disaggregate the seal competence and promote vertical fluid flow. The investigated MTD referred to as MTD-a lies directly over a large hydrocarbon reservoir that is located within the Central Canyon of northern South China Sea, which is examined by using high-resolution 3D seismic and borehole data. Thrust faults and irregular blocks composed of coarse-grained sandstones are observed in the compressional zone of the MTD-a’s toe. More importantly, seismic evidence (e.g., enhanced seismic reflections) suggests that a large amount of hydrocarbons from the underlying reservoir penetrated through the MTD-a along these thrust faults and charged into the coarse-grained sandstone blocks. This clear evidence of thrust faults compromising the MTD’s seal effectiveness and thus facilitating the vertical fluid flow through the non-permeable strata demonstrate the importance of reassessing the seal capacity of MTD.

scholarly journals Android Malware Detection Based on API Pairing

2020 ◽  
Vol 38 (5) ◽  
pp. 965-970
Author(s):  
Jun Guan ◽  
Huiying Liu ◽  
Baolei Mao ◽  
Xu Jiang
Keyword(s):  
Detection Method ◽  
Undirected Graph ◽  
Malware Detection ◽  
Experimental Results ◽  
Application Program Interface ◽  
Coarse Grained ◽  
Practical Significance ◽  
Android Malware ◽  
Android Malware Detection ◽  
Program Interface

Aiming at the problem that the permission-based detection is too coarse-grained, a malware detection method based on sensitive application program interface(API) pairing is proposed. The method decompiles the application to extract the sensitive APIs corresponding to the dangerous permissions, and uses the pairing of the sensitive APIs to construct the undirected graph of malicious applications and undirected graph of benign applications. According to the importance of sensitive APIs in malware and benign applications, different weights on the same edge in the different graphs are assigned to detect Android malicious applications. Experimental results show that the proposed method can effectively detect Android malicious applications and has practical significance.

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