scholarly journals Experimental and Numerical Buckling Analysis for Zig-Zag Model Composite Materials of Clamed-Clamped Rectangular Plates

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
Hussam Hussein Ali ◽  
Majid Habeeb Faidh-Allah
Keyword(s):  
Pressure Drop ◽  
Drag Reduction ◽  
Volume Flow Rate ◽  
Polymer Concentration ◽  
Experimental Results ◽  
Additive Concentration ◽  
Rectangular Plates ◽  
Frictional Drag ◽  
Mean Velocity ◽  
Model Composite

flow, where adding certain amount of drag reducing agent, such as polymer. From addition of that agent, it causes a dramatic frictional drag reduction. This work shows the effect of the pressure drop on a drag reduction along pipe in a horizontal placing with kerosene flow is investigated. The tested fluid was kerosene and poly isobutylene polymer (PIB) with 50 ppm (part per million), 75 ppm, and 100 ppm weight concentration of polymer: Experimental investigation gives more description of this phenomenon. The experimental results illustrate that pressure drop and pressure gradient decreases with increasing of polymer concentration and volume flow rate. The friction factor decreases with increasing of additive concentration and velocity. The drag reduction percentage increases with increasing the mean velocity, polymer concentration and temperature. The experimental results show that maximum drag reduction (DR %) about 19%.

scholarly journals Experimental Investigation of Drag Reduction with polymer of Kerosene flow in a horizontal pipe

2018 ◽  
Vol 8 (01) ◽  
Author(s):  
Adil Abbas Alwan ◽  
Ali Jassim Mohammad
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Drag Reduction ◽  
Volume Flow Rate ◽  
Polymer Concentration ◽  
Experimental Results ◽  
Additive Concentration ◽  
Frictional Drag ◽  
Mean Velocity ◽  
Horizontal Pipe

flow, where adding certain amount of drag reducing agent, such as polymer. From addition of that agent, it causes a dramatic frictional drag reduction. This work shows the effect of the pressure drop on a drag reduction along pipe in a horizontal placing with kerosene flow is investigated. The tested fluid was kerosene and poly isobutylene polymer (PIB) with 50 ppm (part per million), 75 ppm, and 100 ppm weight concentration of polymer: Experimental investigation gives more description of this phenomenon. The experimental results illustrate that pressure drop and pressure gradient decreases with increasing of polymer concentration and volume flow rate. The friction factor decreases with increasing of additive concentration and velocity. The drag reduction percentage increases with increasing the mean velocity, polymer concentration and temperature. The experimental results show that maximum drag reduction (DR %) about 19%.

scholarly journals MATHEMATICAL MODEL TO INVESTIGATE THE DRAG REDUCTION OF KEROSENE WITH POLYMER UNDER TURBULENT FLOW

2019 ◽  
Vol 18 (4) ◽  
pp. 577-588
Author(s):  
Adil A Alwan ◽  
Ali J Mohammad
Keyword(s):  
Pressure Drop ◽  
Drag Reduction ◽  
Flow Rate ◽  
Pipe Flow ◽  
Volume Flow Rate ◽  
Polymer Concentration ◽  
Flow Region ◽  
Two Dimensions ◽  
Turbulent Pipe Flow ◽  
Effective Density

This paper present a mathematical study on drag reduction by polymer additive suchas poly isobutylene (PIB) with kerosene in turbulent pipe flow by using computational fluiddynamic commercial package program (COMSOL 4.4) solution. Theoretically thecomputational study was used to calculate the pressure drop in two dimensions geometricmodel with 6m length and 80 mm width as a diameter of the pipe, Geometric shape has beendrawing by tools of the program windows, and to simulated the flow region mathematicallythe flow region is divide into very small parts (mesh generation). The model that used in themathematical modelling method was (k-?( mathematical turbulent model to study theinternal pipe flow properties. The continuity and momentum equations and two k-? modelequations have been solved by the program to obtain the theoretical results. There variablesthat used in the theoretical study were effective density, effective viscosity, inlet velocity,and outlet pressure. The boundary condition was inlet and outlet velocity, temperature, andpressure of flow, and the velocity (u=0) at the pipe wall. The theoretical calculations showthat the velocity and drag reduction percentage increases with polymer concentration andvolume flow rate increasing where maximum DR% is 15.8% at volume flow rate 500 ??minwith polymer concentration 100 ppm, pressure drop decreases with polymer concentrationincreasing. Friction factor decreases with polymer concentration increased, also shear stressdecrease with polymer concentration increasing.

An Experimental Investigation of Turbulent Drag Reduction in Concentric Annulus Using Particle Image Velocimetry Technique

2013 ◽  
Author(s):  
Fabio Ernesto Rodriguez Corredor ◽  
Majid Bizhani ◽  
Ergun Kuru
Keyword(s):  
Particle Image Velocimetry ◽  
Turbulent Flow ◽  
Drag Reduction ◽  
Particle Image ◽  
Reynolds Shear Stress ◽  
Polymer Concentration ◽  
Mean Flow ◽  
Flow Loop ◽  
Mean Velocity ◽  
Image Velocimetry

Polymer drag reduction is investigated using the Particle Image Velocimetry (PIV) technique in fully developed turbulent flow through a horizontal flow loop with concentric annular geometry (inner to outer pipe radius ratio = 0.4). The polymer used was a commercially available partially hydrolyzed polyacrylamide (PHPA). The polymer concentration was varied from 0.07 to 0.12% V/V. The drag reduction is enhanced by increasing polymer concentration until the concentration reaches an optimum value. After that, the drag reduction is decreased with the increasing polymer concentration. Optimum concentration value of PHPA was found to be around 0.1% V/V. Experiments were conducted at solvent Reynolds numbers of 38700, 46700 and 56400. The percent drag reduction was found to be increasing with the increasing Reynolds number. The study was also focused on analyzing the mean flow and turbulence statistics for fully-turbulent flow using the velocity measurements acquired by PIV. Axial mean velocity profile was found to be following the universal wall law close to the wall (i.e., y+ <10), but it deviated from log law results with an increased slope in the logarithmic zone (i.e., y+ >30). In all cases of polymer application, the viscous sublayer (i.e., y+ <10) thickness was found to be higher than that of the water flow. Reynolds shear stress in the core flow region was found to be decreasing with the increase in polymer concentration.

CFD Modelling and Validation of Newtonian and Non-Newtonian Fluids in Curved Conduits

2015 ◽  
Vol 786 ◽  
pp. 181-187
Author(s):  
Abdulrahman Yousif ◽  
Azuraien Japper-Jaafar
Keyword(s):  
Pressure Drop ◽  
Drag Reduction ◽  
Reynolds Stress ◽  
Tap Water ◽  
Newtonian Fluids ◽  
Experimental Results ◽  
Polymer Additives ◽  
Centrifugal Forces ◽  
Cfd Modelling

CFD modelling of drag reduction agents (also called Flow Improvers) polymer additives dissolved in a newtonian solvent (UTP tap Water) was carried out in a curved conduit, A 7 equation Reynolds stress set of equations was used to simulate this flow. The purpose of this simulation is validate experimental results that show unusual pressure drop behaviour. CFD experiments show that there is pressure build-up near the end of the curved conduit due to severe centrifugal forces produced by the fluid, confirming the validity of the experimental results.

scholarly journals Grafted natural polymer as new drag reducing agent: An experimental approach

2012 ◽  
Vol 18 (3) ◽  
pp. 361-371 ◽  
Author(s):  
Hayder Abdulbari ◽  
Nuraffini Kamarulizam ◽  
A.H. Nour
Keyword(s):  
Drag Reduction ◽  
Closed Loop ◽  
Reducing Agent ◽  
Water Soluble ◽  
Experimental Results ◽  
Circulation System ◽  
Additive Concentration ◽  
Gas Oil ◽  
Media Type ◽  
Type Water

The present investigation introduces a new natural drag reducing agent which has the ability to improve the flow in pipelines carrying aqueous or hydrocarbon liquids in turbulent flow. Okra (Abelmoschus esculentus) mucilage drag reduction performance was tested in water and hydrocarbon (gas-oil) media after grafting. The drag reduction test was conducted in a buildup closed loop liquid circulation system consists of two pipes 0.0127 and 0.0381 m Inside Diameter (ID), four testing sections in each pipe (0.5 to 2.0 m), tank, pump and pressure transmitters. Reynolds number (Re), additive concentration and the transported media type (water and gas-oil), were the major drag reduction variables investigated. The experimental results show that, new additive drag reduction ability is high with maximum percentage of drag reduction (%Dr) up to 60% was achieved. The experimental results showed that the drag reduction ability increased by increasing the additive concentration. The %Dr was found to increase by increasing the Re by using the water-soluble additive while it was found to decrease by increasing the Re when using the oil-soluble additive. The %Dr was higher in the 0.0381 m ID pipe. Finally, the grafted and natural mucilage showed high resistance to shear forces when circulated continuously for 200 seconds in the closed-loop system.

Effects of Interfacial Position on Drag Reduction in a Superhydrophobic Microchannel

2008 ◽  
Author(s):  
Ryan Enright ◽  
Tara Dalton ◽  
Tom N. Krupenkin ◽  
Paul Kolodner ◽  
Marc Hodes ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Drag Reduction ◽  
Flow Rate ◽  
Contact Line ◽  
Superhydrophobic Surface ◽  
Parallel Plate ◽  
Laser Scanning ◽  
Liquid Interface ◽  
Experimental Results ◽  
Superhydrophobic Surfaces

The use of superhydrophobic surfaces in confined flows is of particular interest as these surfaces have been shown to exhibit a drag reduction effect that is orders of magnitude larger than those due to molecular slip. In this paper we present experimental results of the pressure-driven flow of water in a parallel-plate microchannel having a no-slip upper wall and a superhydrophobic lower wall. Pressure-drop versus flow-rate measurements characterize the apparent slip behavior of the superhydrophobic surfaces with varying pillar-to-pillar pitch spacing and pillar diameter. The superhydrophobic surface consists of a square array of cylindrical pillars that are fabricated by deep reactive ion etching on silicon and coated with a hydrophobic fluoropolymer. A major challenge, in correlating our experimental results with existing theoretical predictions, is uncertainty in the location of the gas/liquid interface and the associated gas/liquid/solid contact line within the pillar features comprising the superhydrophobic surface. We present experimental results, from laser-scanning confocal microscopy, that measure the location of the gas-liquid interface and associated contact line for fluid flowing through a parallel-plate microchannel. Knowledge of the contact line location is then used to correlate experimental pressure-drop versus flow-rate data with a theoretical model based on porous-flow theory that takes into account partial penetration of liquid into a superhydrophobic surface.

IMPROVEMENT OF SHARARA CRUDE OIL FLOW USING POLYSTYRENE AND POLYDIMETHYLSILOXANE AS DRAG REDUCING AGENTS

2019 ◽  
Vol 2 (1) ◽  
pp. 14-28
Author(s):  
Rabeeah H. Sultan ◽  
Abduelmaged B. Abduallah ◽  
Omar M. Sultan M. Sultan
Keyword(s):  
Drag Reduction ◽  
Crude Oil ◽  
Friction Factor ◽  
Polymer Concentration ◽  
Polymeric Materials ◽  
Reducing Agents ◽  
Additive Concentration ◽  
Pumping System ◽  
Polymeric Additives ◽  
Oil Flow

In this study the applicability of the Libyan crude oil flow induced by improved lab pumping system was examined in order to evaluate the effect of adding polymeric materials of Polystyrene and Polydimethylsiloxane as drag reducing agents (DRA) on the flow of Sharara crude oil in the pipeline. The polymers are injected through a pumping system at different concentrations rounded between (10-100) ppm. Several experiments were carried out to determine the best concentration of polymer, which satisfied lowest drag force on of crude oil flow rate. Furthermore, the effect of additive concentration on the Viscosity(μ), friction factor (ƒ), percentage drag reduction (%DR) and the amount of flow increases (%FI) were determined. The results show that the activities of Polydimethylsiloxane for Drag reduction is higher than drag reduction for Polystyrene. However, the %DR is generally increased with increasing of polymer concentration for all tested additives. It is progressively increased with increasing Reynolds number (Re) at any specific concentration of the polymeric additives. The friction factor is well correlated with Reynolds numbers and polymer concentration according to the relation of the form ƒ= k ReaCb, the results showed good agreement between the observed values and the predicted ones.

Measurement of Turbulence Modification by Microbubbles Causing Frictional Drag Reduction

2003 ◽  
Author(s):  
Atsuhide Kitagawa ◽  
Kazuyasu Sugiyama ◽  
Masa-aki Ashihara ◽  
Koichi Hishida ◽  
Yoshiaki Kodama
Keyword(s):  
Liquid Phase ◽  
Drag Reduction ◽  
Measurement Data ◽  
Turbulence Structure ◽  
Frictional Drag ◽  
Mean Velocity ◽  
Gas Phases ◽  
Structure Of Flow ◽  
Image Velocimetry ◽  
Velocity Turbulence

In this research, in order to clarify the mechanism for drag reduction caused by microbubbles, the turbulence structure of flow field including microbubbles in a horizontal channel is experimentally investigated using particle tracking velocimetry and laser induced fluorescence (PTV/LIF) technique. First, we discuss the particle image velocimetry (PIV) and PTV results for the liquid phase velocity detection. Second, using instantaneous measurement data, we obtain the profiles of the mean velocity, turbulence intensity and Reynolds stress of the liquid phase. In order to obtain the information of both the liquid and gas phases simultaneously, furthermore, we propose a new system based on the combination of PTV, LIF and infrared shadow technique (IST).

scholarly journals Drag Reduction Properties of Nanofluids in Microchannels

2015 ◽  
Vol 12 (2) ◽  
pp. 60 ◽  
Author(s):  
H.A. Abdulbari ◽  
F.L.W. Ming
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Drag Reduction ◽  
Single Phase ◽  
Critical Concentration ◽  
Primary Objective ◽  
Experimental Results ◽  
Water Suspensions ◽  
Micro Channels

An experimental investigation of the drag reduction (DR) individualities in different sized micro channels was carried out with nanopowder additives (NAs) (bismuth(III) oxide, iron(II/III) oxide, silica, and titanium(IV) oxide) water suspensions/fluids. The primary objective was to evaluate the effects of various concentrations of NAs with different microchannel sizes (50, 100, and 200 µm) on the pressure drop of a system in a single phase. A critical concentration was observed with all the NAs, above which increasing the concentration was not effective. Based on the experimental results, the optimum DR percentages were calculated. The optimum percentages were found to be as follows: bismuth III oxides: ~65% DR, 200 ppm and a microchannel size of 100 µm; iron II/III oxides: ~57% DR, 300 ppm, and a microchannel size of 50 µm; titanium IV oxides: ~57% DR, 200 ppm, and a microchannel size of 50 µm, and silica: 55% DR, 200 ppm, and a microchannel size of 50 µm.  

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