scholarly journals Correlation of Pressure Drop in the Sintered Fibrous Porous Tube with Permeability and Friction Coefficient

2021 ◽  
Vol 1096 (1) ◽  
pp. 012005
Author(s):  
K Enoki ◽  
T Kobayashi ◽  
R Watanabe ◽  
Y Otomo ◽  
A Akisawa ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam

AbstractThis research aims of compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes include the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. The pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Increasing 0.3 wt.% of TiO2 and MWCNTs into the oil caused to improvement in viscosity index. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.


Author(s):  
Mohammad Amir Hasani ◽  
Mahmood Norouzi ◽  
Morsal Momeni Larimi ◽  
Reza Rooki

Cuttings transport from wellbore annulus to the surface via drilling fluids is one of the most important problems in gas and oil industries. In the present paper, the effects of viscoelastic property of drilling fluids on flow through wellbore annulus are studied numerically by use of computational fluid dynamics simulation in OpenFOAM software. This problem is simulated as the flow between two coaxial annulus cylinders and the inner cylinder is rotating through its axes. Here, the Giesekus model is used as the nonlinear constitutive equation. This model brings the nonlinear viscosity, normal stress differences, extensional viscosity and elastic property. The numerical solution is obtained using the second order finite volume method by considering PISO algorithm for pressure correction. The effect of elasticity, Reynolds number, Taylor number and mobility factor on the velocity and stress fields, pressure drop, and important coefficient of drilling mud flow is studied in detail. The results predicted that increasing elastic property of drilling mud lead to an initial sharp drop in the axial pressure gradient as well as Darcy-Weisbach friction coefficient. Increasing the Reynolds number at constant Taylor number, resulted an enhancing in the axial pressure drop of the fluid but Darcy-Weisbach [Formula: see text] friction coefficient mainly reduced.


Author(s):  
Hongwei Sun ◽  
Mohammad Faghri

The overall object of this paper is a systematic study of gaseous flows in two-dimensional micro- and nano-channels in terms of the effects of compressibility, rarefaction, and surface roughness which are usually neglected in conventional flow analysis, using direct simulation Monte Carlo (DSMC) method. The flows are mainly in slip and transition regimes that are often encountered in Microelectromechanical Systems (MEMS), Nanoelectromechanical Systems (NEMS), and other microscale devices in diverse fields like molecular biology, space propulsion, and particle physics. For the effect of compressibility, two flows with same outlet Knudsen number (Kn) but different pressure drop ratios (case1:1.3, case2: 4.5) were simulated. It was found that high pressure drop flow (case2) show a 15% higher friction coefficient than that of a fully developed flow while the low pressure drop flow (case1) is consistent with incompressible flow prediction. The inspection for the velocity profile development shows that when pressures drop increase along the channel, the center-line velocity become flatten and the velocity gradients near the wall are higher compared with parabolic velocity profile. The effect of rarefaction was studied by simulating two nitrogen flows with low-pressure drop ratio (= 1.9) but different Kn numbers. (case3: 0.043, case4: 0.083). The pressure distribution, velocity profile, local friction coefficient are checked. The comparison with continuum flow theory (fRe = 24.0) shows that the rarefactions reduce the friction coefficient by 22% and 36% for case3 and case4, respectively. Apparent velocity slips along the channel wall exist for these flows. A locally fully developed model based on local velocity slip and fully developed assumptions predicts the friction coefficient accurately but fails in transition region where the Kn is over 0.1. Two important ratios are investigated for surface roughness effect in micro- and nano-channel flows: relative roughness and distribution of roughness. The DSMC results show that the surface roughness has more profound effect for a lower Kn number microchannel flow. The roughness distribution also plays a very important role in microchannel flows. The denser the roughness distribution, the higher friction coefficient. The future work will focus on flows in free-molecular flow regime and three-dimension geometries.


2020 ◽  
Author(s):  
Hadi Pourpasha ◽  
Saeed Zeinali Heris ◽  
Yaghob Mohammadfam

Abstract This research work purpose to compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and Titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes are including the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. Also, the pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The diameter of MWCNTs and TiO2 nano additives were ranging from 5 nm to 16.1 nm and 7.9 nm to 13.9 nm, respectively. The average particle size of TiO2 and MWCNTs nano additives in 0.4 wt.% in the pure lubricant were 221 nm and 320 nm, respectively. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Nano lubricants with 0.3 wt.% of TiO2 and 0.4 wt.% of MWCNTs nano additives illustrated the maximum improvement in the flash point temperature with enhancement 4 °C and 10 °C. By increasing of 0.3 wt.% of TiO2 and MWCNTs into the pure oil caused to improve in viscosity index with enhancement 6.68% and 2.43% compared to the pure lubricant, respectively. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.


1976 ◽  
Vol 43 (4) ◽  
pp. 594-598 ◽  
Author(s):  
D. E. Kenyon

The time-dependent filtration of liquid through the wall of a soft, porous tube can be quite unlike that of a hard, porous tube. Under conditions described, the seepage is limited to thin layers near each surface, and in one of these layers, liquid seepage proceeds in a direction opposite to the sense of the applied pressure drop across the tube wall. This occurs because it is impossible to produce isotropic contact stress in the solid if kept at constant volume by the slowness of seepage. The liquid must then bear the entire isotropic stress.


Author(s):  
C. O. Ríos Orozco ◽  
N. C. Uzarraga-Rodriguez ◽  
A. Gallegos-Muñoz ◽  
J. M. Riesco Ávila

In this work the characterization of the water flow through a flat solar collector and solar collectors systems interconnected is presented. This allows analyzing the behavior of flow distribution in the headers pipe and riser tubes of flat solar collectors. The hydraulic analysis allows determining if the water flow inside the risers presents a no-uniform distribution, having that the mass flow rate through riser tubes increases when they are located a greater distance from inlet of header pipe. This effect also occurs at system composed of several solar collectors interconnected, through their own header pipes, which behaves like a simple flat solar collector with header pipe longer and major number of riser tubes. The hydraulic model of the water flow through a flat solar collector, equipped with different number of riser tubes, is modeled in the FLUENT® software and comparing with theory and methodology knowing for the calculation of pressure drop in pipe sections and accessories. The results show the curves obtained for hydraulic behavior for the cases of study, where is observed that the water flow is no-uniform. This no uniformity provokes that the friction coefficient varies depending of the position of riser tube.


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