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Edvaldo Sabadini - One of the best experts on this subject based on the ideXlab platform.
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bis urea based supramolecular polymer the first self assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polym...
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Bis-urea-based supramolecular polymer: The first self-assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polymers, due to irreversible scission of the backbone. In this letter, we present the first hydrodynamic Drag Reducer for hydrocarbons based on a self-assembled polymer formed from the reversible aggregation of bis-urea monomers. This system forms two competitive polymeric structures--the tube (T) and the filament (F) forms--which are in equilibrium with each other. Our rheology results in octane and toluene are fully consistent with calorimetry data and show that only the longest form, T, is able to promote the Drag reduction effect.
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new experimental technique to measure the efficiency of Drag Reducer additives for oil samples
Energy & Fuels, 2009Co-Authors: Marcelo A Da Silva, Nelson Rocha, Carlos H M De Carvalho, Edvaldo SabadiniAbstract:A comparative study about the efficiency of five commercial products used to facilitate the transport of oil through pipelines was developed using a new experimental technique. The technique is based on the applied torque necessary to keep the samples rotating in turbulent flow. The hydrodynamic Drag reduction is proportional to the difference on the torque applied in oil samples with and without the additive. The experiments were developed in a Couette cell of a rheometer, which is sensitive to determine levels of Drag reduction with high accuracy. The method was tested by using five commercial samples of Drag Reducers added to a Brazilian oil sample. Their efficiency, as well as their optimum concentrations, was compared. The method has proven very attractive mainly due to the low amount of sample and the short time required for the measurements.
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firefighting foam stability the effect of the Drag Reducer poly ethylene oxide
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2003Co-Authors: R C R Figueredo, Edvaldo SabadiniAbstract:Abstract The presence in fluids of very small amounts of high molecular weight polymers produces high levels of Drag reduction in the fluid flow. This phenomenon, often termed the Toms Effect, can be used in firefighting, mainly due to the reduction in the energy necessary to pump water. The use of one of the most efficient Drag reducing agents—poly(ethylene oxide) (PEO)—dissolved in the firefighting foam concentrate can significantly increase foam flow. This paper describes studies of the stability of foam generated from a commercial firefighting foam concentrate with added PEO. These studies were based on the lifetime of foams generated with and without small concentrations of PEO. It was observed that the presence of PEO increases the lifetime of the foam. This result is attributed to changes in the drainage rate due to the adsorption of the polymer at the liquid–air foam interface. The adsorption is probably a consequence of the polar interaction of the ether group of PEO and the polar head of the surfactant.
Laurent Bouteiller - One of the best experts on this subject based on the ideXlab platform.
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bis urea based supramolecular polymer the first self assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polym...
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Bis-urea-based supramolecular polymer: The first self-assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polymers, due to irreversible scission of the backbone. In this letter, we present the first hydrodynamic Drag Reducer for hydrocarbons based on a self-assembled polymer formed from the reversible aggregation of bis-urea monomers. This system forms two competitive polymeric structures--the tube (T) and the filament (F) forms--which are in equilibrium with each other. Our rheology results in octane and toluene are fully consistent with calorimetry data and show that only the longest form, T, is able to promote the Drag reduction effect.
Kelly R. Francisco - One of the best experts on this subject based on the ideXlab platform.
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bis urea based supramolecular polymer the first self assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polym...
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Bis-urea-based supramolecular polymer: The first self-assembled Drag Reducer for hydrocarbon solvents
Langmuir, 2010Co-Authors: Edvaldo Sabadini, Kelly R. Francisco, Laurent BouteillerAbstract:The hydrodynamic Drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of Drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective Drag Reducers. Giant micelles are interesting in promoting Drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polymers, due to irreversible scission of the backbone. In this letter, we present the first hydrodynamic Drag Reducer for hydrocarbons based on a self-assembled polymer formed from the reversible aggregation of bis-urea monomers. This system forms two competitive polymeric structures--the tube (T) and the filament (F) forms--which are in equilibrium with each other. Our rheology results in octane and toluene are fully consistent with calorimetry data and show that only the longest form, T, is able to promote the Drag reduction effect.
Zhongwei Huang - One of the best experts on this subject based on the ideXlab platform.
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a model of calculating the circulating pressure loss in coiled tubing ultra short radius radial drilling
Petroleum Exploration and Development, 2012Co-Authors: M A Dongjun, Li Gensheng, Zhongwei Huang, L I JingbinAbstract:Abstract By analyzing the relationship between measured values of pressure loss in a high-pressure hose and calculated values of metal tubing pressure loss formula under the same condition, a calculation formula of pressure loss in a high-pressure hose is revised on the basis of the existing formula, and a model of calculating the circulating pressure loss in coiled tubing ultra-short radius radial drilling is established by theoretical derivation. The effects of tubing diameter, tubing length, pump delivery and fluid dynamic viscosity on each part of pressure loss in circulation system are studied by the pressure loss calculating model. The pressure loss in coiled and straight parts of 0.025 4 m (1 in) coiled tubing is about 8-10 times bigger than the pressure loss of 0.038 1 m (1.5 in) coiled tubing, and the pressure loss in high-pressure hose accounts for a large proportion in circulation system, about 86% in this study; and with Drag Reducer added in clear water, the pressure loss is about half of clear water pressure loss under the same condition.
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A model of calculating the circulating pressure loss in coiled tubing ultra-short radius radial drilling
KeAi Communications Co. Ltd., 2012Co-Authors: Zhongwei Huang, Jilei Niu, Cheng Hou, Mingjuan LiuAbstract:By analyzing the relationship between measured values of pressure loss in a high-pressure hose and calculated values of metal tubing pressure loss formula under the same condition, a calculation formula of pressure loss in a high-pressure hose is revised on the basis of the existing formula, and a model of calculating the circulating pressure loss in coiled tubing ultra-short radius radial drilling is established by theoretical derivation. The effects of tubing diameter, tubing length, pump delivery and fluid dynamic viscosity on each part of pressure loss in circulation system are studied by the pressure loss calculating model. The pressure loss in coiled and straight parts of 0.025 4 m (1 in) coiled tubing is about 8-10 times bigger than the pressure loss of 0.038 1 m (1.5 in) coiled tubing, and the pressure loss in high-pressure hose accounts for a large proportion in circulation system, about 86% in this study; and with Drag Reducer added in clear water, the pressure loss is about half of clear water pressure loss under the same condition. Key words: coiled tubing, radial drilling, high-pressure hose, circulation system, friction factor, pressure los
K. L. Bessa - One of the best experts on this subject based on the ideXlab platform.
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Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats
Brazilian Journal of Medical and Biological Research, 2011Co-Authors: K. L. Bessa, J. F. Belletati, Luciano Dos Santos, Luciana V Rossoni, J. P. OrtizAbstract:This study was designed to evaluate the effect of Drag Reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and Drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7%), WSS (Wistar/E+: 36; SHR/E+: 40%) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.
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Drag reduction by polymers additives in laminar and turbulent pulsatile flow in tail arterial bed from normotensive and hypertensive rats and rigid tubes.
Escola Politécnica, 2008Co-Authors: K. L. BessaAbstract:Nesse trabalho, foi analisada a redução de arrasto, a partir da utilização de duas bancadas experimentais, onde uma delas está situada no laboratório de Mecânica dos Fluidos (EPUSP) e a outra, no laboratório de Fisiologia Vascular (ICB-USP). A redução de arrasto foi investigada a partir do uso dos seguintes polímeros: poliacrilamida 1822S e 1340S, polietileno glicol (PEG4000) e óxido de polietileno (Polyox WSR-301). O comportamento reológico das soluções poliméricas do PEG4000 e das poliacrilamidas foi adquirido experimentalmente, enquanto do Polyox WSR-301 foi obtido da literatura. Esses polímeros foram utilizados na bancada experimental da EPUSP, simulador hidrodinâmico, mas somente o PEG4000 foi utilizado na bancada experimental do ICBI em leitos arteriais caudais de ratos normotensos (Wistar) e espontaneamente hipertensos (SHR). No simulador hidrodinâmico, foi estudada a redução de arrasto em escoamentos pulsáteis laminares e turbulentos, cuja faixa de Reynolds varia entre 2300 a 13700, com concentrações poliméricas que variaram entre 5 e 100 ppm, porém para o PEG4000 essa concentração atingiu valor de 5000 ppm. Em leitos arteriais caudais de ratos, a redução de arrasto foi analisada para escoamento laminar, cuja faixa de Reynolds varia entre 100 e 700, com concentração polimérica de 5000 ppm. Além disso, a redução de arrasto foi estudada na presença e ausência das células endoteliais. Simulações computacionais utilizando o método dos volumes finitos (Fluent) foram realizadas a partir dos dados obtidos da bancada experimental do ICB-I, para avaliar a distribuição da tensão de cisalhamento sobre a parede do vaso na presença e ausência das células endoteliais e do PEG4000, considerando a parede da artéria rígida. A partir dos dados obtidos da análise da viscosidade, ficou constatado que o PEG4000 com concentração de 5000 ppm e as poliacrilamidas 1822S e 1340S com concentrações de 5 e 10 ppm apresentaram comportamento de fluido Newtoniano. Para as poliacrilamidas, concentrações poliméricas acima de 10 ppm apresentaram comportamento de fluido não-Newtoniano. De acordo com a literatura, o Polyox WSR-301 apresentou comportamento de fluido Newtoniano para todas as concentrações poliméricas utilizadas nesse trabalho. O PEG4000 não apresentou o fenômeno da redução de arrasto em nenhuma concentração polimérica analisada, quando aplicado na bancada experimental da EPUSP. As poliacrilamidas e o Polyox WSR-301 apresentaram reduções de arrasto que foram dependentes do número de Reynolds e da concentração utilizada, muito embora o Polyox WSR-301 tenha se mostrado mais eficiente em promover esse fenômeno. Nos leitos arteriais caudais, o PEG4000 apresentou redução de arrasto para a concentração de 5000 ppm, que foi acentuada pela presença das células endoteliais. Os valores da tensão de cisalhamento foram maiores para o animal SHR quando comparados com o animal Wistar. Além disso, no animal Wistar, o endotélio controlou o aumento dessa tensão via produção de substâncias vasodilatadoras, mas apresentou disfunção no animal SHR. A partir dos resultados apresentados acima, podese concluir que o Polyox WSR-301 é mais eficiente para promover a redução de arrasto em tubos rígidos. Por outro lado, muito embora o PEG4000 não tenha apresentado efeito na bancada experimental da EPUSP, esse se mostrou um bom redutor de arrasto em leitos arteriais caudais, tendo sua ação intensificada pela presença das células endoteliais.In this work, the Drag reduction was analyzed in two benches located at Laboratory of Fluid Mechanics at Polytechnic School (EPUSP) and at Laboratory of Vascular Physiology at Institute of Biomedical Science (ICB-USP). The Drag reduction was investigated for the following polymers: polyacrilamide 1822S and 1340S, polyethylene glycol (PEG4000) and polyethylene oxide (Polyox WSR-301). The rheological behavior of polymeric solutions of polyacrilamide and PEG4000 was acquired experimentally; while it was obtained from the literature for Polyox WSR-301. All of these polymers were used in the hydrodynamic simulator, but only PEG4000 was employed in the tails arterial bed from normotensive (Wistar) and spontaneously hypertensive rats (SHR) at ICB-1. In the hydrodynamic simulator, the Drag reduction was analyzed in laminar and turbulent pulsatile flow, in the range varying between 2300 and 13700, with polymeric concentrations between 5 and 100 ppm, but for PEG4000, concentration has reached 5000 ppm. On the other hand, in the tail arterial beds, the Drag reduction was analyzed for laminar flow, in the range between 100 and 700, with polymeric concentration of 5000 ppm. In addition, it was studied in the presence and absence of endothelial cells. Computational simulation using the finite volume method (Fluent) was performed using data obtained from ICB-1 in order to analyze the wall shear stress distribution along of wall vessel both in the presence and absence of endothelial cells and PEG4000, considering the rigid walls. Polyacrilamide 1822S and 1340S as well as PEG4000 showed behavior of Newtonian fluid in the following concentrations: 5 and 10 ppm and 5000 ppm, respectively. On the other hand, for polyacrilamides, concentrations higher than 10 ppm showed behaviour of non- Newtonian fluids. According to the literature, the Polyox WSR-301 behaved as a Newtonian fluid in all concentrations used in this work. At EPUSP\'s bench, while PEG4000 did not show Drag reduction for any polymeric concentration analyzed, this phenomenon could be seen for polyacrilamides and Polyox WSR-301, being dependent on Reynolds number as well as polymeric concentration. More important, Polyox WSR- 301 showed to be the most efficient Drag Reducer of them. Interestingly, in the assays employing the tail arterial beds, PEG4000 showed Drag reduction in the concentration of 5000 ppm and it was increased by the presence of the endothelial cells. Thus, Polyox WSR-301 seems to be more efficient to promote Drag reduction in the rigid tubes. On the other hand, while PEG4000 did not show Drag reduction at EPUSP\'s bench, it was a good Drag Reducer in the tail arterial beds, being intensified by the action of endothelial cells