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Article
Drag Reduction of Crude Oil Flow in Pipelines Using Sodium Dodecyl Benzene Sulfonate Surfactant

Authors: Ali A. A. Hadi --- G. A. R. Rassoul
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2007 Volume: 8 Issue: 2 Pages: 29-34
Publisher: Baghdad University جامعة بغداد

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Abstract

In the present worA a closed loop circulation system consist of three testing sections was designed and constructed. The testing sections made from (3m) of commercial carbon steel pipe of diameters (5.08, 2.54 and 1.91 cm) . Anionic surfactant (SDBS)with concentrations of (50 100, 150, 200 and 250 ppm) was tested as a drag reducing agent The additive(SDDS) studied using crude oilfrom south of Iraq. The flow rates of crude oil were used 08 and 2.54cm ID.pipes are (1 — 12) m3/hr while (1-6) ra were used in 1.91 cm ID. pipe. Percentage drag reduction (%Dr) was found to increase by increasing solution velocity, pipe diameter and additives concentration (La increasing Renolds number).Also it was found that there is no change in apparent physical properties (viscosity) of crude oil after the addition of SDBS, The higher value of drag reduction of 54% in 5 cm ID. was observed using 250 ppm SDBS surfactant dissolved in the used crude oil at flow rate of 12 m Friction factor was calculated from experimental data. The friction factors values for pure solvent lies near or at Blasius asymptote suggestedfor flow of Newtonian fluids. Afier the addition of small amount of SDI3S, the friction factor values were positioned below Blasius asymptote toward Virk maximum drag reduction asymptote, &hich was never reached.


Article
Effect of Riblets Geometry on Drag Reduction
تأثیر شكل الحزوز على تخفیض الكبح

Authors: Nibras M. Mahdi --- Ikhlase M. Fayed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2010 Volume: 28 Issue: 22 Pages: 6518-6535
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The effect of longitudinal riblet surface models (U, V and semi-Circular and U with fillet corner riblets) on the performance of unsymmetrical airfoil (NACA23015) which has been investigated numerically and experimentally. Numerical investigation involve examining drag reduction by solving the governing equations (Continuity and Navier-Stokes equations) using the known package FLUENT version (6.1) in turbulent regime with appropriate turbulence model (κ-ε). Also measurement in experimental work will be carried out. The results indicate that the riblet surface models are the key parameters for controlling the boundary layer characteristic. The most effective riblet surface is U-riblet with fillet model (Mo.4, h=0.1mm), by compare to smooth model, the results show a small increment in lift slope curve about (9%) and total drag decrease (12%) over the angles of attack range from (0° to 17°).

ذات زاوية محدبة) على أداء U نصف دائره و ، V ، U) يتناول البحث تاثير الحزوز الطوليه عددياً وعملياً. البحث العددي يتضمن حل المعادلات (NACA جناح ذو المقطع غير المتناظر ( 23015 الحاكمة (معادلات الأستمرارية ونافير-ستوكس) لدراسة امكانية تخفيض الكبح باستخدام برنامج وكذلك أجريت القياسات في العمل .(κ-ε) في نظام اضطرابي مع نموذج الأضطراب (FLUEN6.1) المختبري. النتائج بينت ان انواع الحزوز هي عامل مهم في السيطرة على خصائص الطبقة المتاخمة بالمقارنة مع النموذج (Mo.4, h=0.1mm) مع زاوية محدبة U والنموذج الأكثر فعالية هو النموذج ( الأملس، حيث بينت النتائج زيادة صغيرة في منحني الرفع (% 9) وانخفاض في الكبح الكلي (% 12 .( لمدى من زوايا الهجوم (° 0 الى ° 1

Keywords

Drag reduction --- Riblets --- Airfoils


Article
Problems of Heavy Oil Transportation in Pipelines And Reduction of High Viscosity

Authors: Ayad A. Abdulrazak --- Mohammed Al-Khatieb --- Haidar A. Faris
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2015 Volume: 16 Issue: 3 Pages: 1-9
Publisher: Baghdad University جامعة بغداد

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Abstract

Drag has long been identified as the main reason for the loss of energy in fluid transmission like pipelines and other similar transportation channels. The main contributor to this drag is the viscosity as well as friction against the pipe walls, which will results in more pumping power consumption. The aim in this study was first to understand the role of additives in the viscosity reduction and secondly to evaluate the drag reduction efficiency when blending with different solvents. This research investigated flow increase (%FI) in heavy oil at different flow rates (2 to 10 m3/hr) in two pipes (0.0381 m & 0.0508 m) ID By using different additives (toluene and naphtha) with different concentrations (2, 4, 6, 8 and 10) wt. % at 35ᵒ C.The results of this study showed the following:•Increasing values of Dr% and FI% for all drag reducing agents with heavy oil. Increasing values of Dr% with increasing of Reynolds number, fluid velocity and additive concentration.•With the larger pipe diameter, performances of drag reduction occur is much better than smaller pipe diameter.•The additives (toluene and naphtha) reduce the high viscosity of used heavy oil.•Naphtha is more efficient as viscosity reducer than toluene. Finally, all these results help the understanding of the flow properties of heavy oils and aim to contribute to the improvement of their transport.

Keywords

Heavy oil --- drag reduction


Article
Improvement Heavy Oil Transportation in Pipelines (Laboratory study)

Authors: Ayad A. Abdulrazak --- Haidar A. Faris
Journal: Journal of Petroleum Research & Studies مجلة البحوث والدراسات النفطية ISSN: 22205381 Year: 2016 Volume: 272 Issue: 13 Pages: 200-209
Publisher: Ministry of Oil وزارة النفط

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Abstract

Since from the past, drag has been identified as the main reason for the loss of energy in pipelines and other similar transportation channels. The contribution of this drag is due to mainly viscous of the flow as well as friction against the pipe walls. These energy losses can be identified through pressure drop, which will results in more pumping power consumption.Due to their very high viscosity heavy oil cannot be transported as such in pipelines and required additional treatments [1].This work studied flow increase (%FI) in heavy oil at different flow rates (2 to 10 m3/hr) in two pipes (0.0381 m & 0.0508 m) ID. By using different additives (toluene and naphtha) with different concentrations (2, 4, 6, 8 and 10) %wt at 27ᵒC.The results of this study showed Increasing values of FI % and Maximum Dr% of 40.48% and 37.03 % were obtained using heavy oil containing 10% wt of naphtha flowing in pipes of 0.0508 and 0.0381 m I.D. at 27°C respectively.Increasing values of %Dr with increasing of Reynolds number, fluid velocity and additive concentration, the used additives (toluene and naphtha) reduce the high viscosity of used heavy oil, and naphtha is more efficient as viscosity reducer than toluene.All these results show treatment heavy oil and improvement their transport in pipelines.


Article
DRAG COEFFICIENT REDUCTION IN CYLINDRICAL BODIES USING A DOWNSTREAM WAVY FIN
تخفيض معامل السحب للاجسام الاسطوانية باستخدام زعنفة موجية

Author: kamal Mohammed Ali كمال محمد علي
Journal: AL-TAQANI مجلة التقني ISSN: 1818653X Year: 2011 Volume: 24 Issue: 6 Pages: 25-32
Publisher: Foundation of technical education هيئة التعليم التقني

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Abstract

An investigation was performed to show how drag force and hence drag coefficient will be reduced when using a wavy shape fin attached to the trailing edge of a cylindrical body fitted normally in air stream of an open loop blower type wind tunnel.Using wavy fin attached to cylinder body to offset any probable flow separation which may be occurred when using straight fins. Drag force measured by using momentum equation between upstream and downstream to the cylinder , this done by measuring differential pressure at a ( 10 *10 ) mesh of points chosen upstream and downstream . Work was done by testing the cylinder with no fin first then attaching straight fin and finally by attaching wavy fin in order to make result comparable.Investigation was done in sub-critical flow regime with variable air speeds which creates of (Re) from ( 4*10³ and 16*10³ ) with seven increments, and with 10 cm cylinder diameter and 10 cm straight fin width i.e. ( L/d = 1 ) and apparent ratio of 0.5 . Results are then compared with that of no fin and with straight fin .Results show that to a certain limit of (Re) there is a considerable reduction in drag coef. compared with straight and no fin cylinder then it tends to decrease and become constant beyond that limit ,and there is a high reduction at low Reynolds number

هذا البحث يظهر كيف أن قوة السحب(Fd) وبالتالي معامل السحب (Cd) ستنخفض باستخدام زعنفة على شكل موجة مثبتة عند الطرف الخلفي لجسم أسطواني مثبت بشكل عمودي على مجرى الهواء في مجرى هوائي من النوع المفتوح النافخ للهواء . تستخدم هذه الزعنفة المثبتة على جسم الأسطوانة لغرض التخلص من أي انفصال في الجريان يمكن احتماله والذي لوحظ وجوده عند استخدام زعنفة مسطحة. في هذا البحث تم قياس قوة السحب باستخدام معادلة الزخم بين طرفي الأسطوانة وهذا يتأتى عن طريق قياس فرق الضغط في (10*10) نقطة موزعة أمام وخلف الأسطوانة. هذا العمل نفذ باستخدام أسطوانة بدون زعنفة أولا ثم باستخدام نفس الأسطوانة ولكن باستخدام زعنفة مستقيمة وأخير باستخدام نفس الأسطوانة ولكن مع زعنفة على شكل موجة جيبية حتى يمكن مقارنة النتائج بشكل أدق.هذا البحث أجري عند منطقة (الجريان تحت الحرج) مع تغير في سرعة الهواء والتي تنتج رقم رينولد 0.4*10≤ Re ≤1.6*10)) مع 7 زيادات. الزعنفة المستقيمة طولها 10سم وزعنفة موجية طولها 10سم أيضا وقطر أسطوانة 10سم أي أن(L ∕ D=1)ومعامل الظهور يساوي 0,5 .النتائج بعد ذلك قورنت مع تلك الأسطوانة الخالية من الزعانف وكذلك مع تلك التي تحتوي على زعنفة مسطحة. وجد أنه إلى حد معين من رقم رينولد هناك تغير واضح وملحوظ في معامل السحب مقارنة مع الأسطوانتين الأولى والثانية بعد ذلك التناقص يصبح ثابتا وأن هناك تخفيض كبير في معامل السحب عند رقم رينولد الواطئ .


Article
Effect of Molecular Weight on Turbulent Drag Reduction with Polyisobutylene
تأثير الوزن الجزيئي على تقليل الإعاقة الاضطرابي بواسطة بوليمر الايزوبيوتيلين

Author: Dr. Jabir Shanshool د. جابر شنشول جمالي
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2008 Volume: 11 Issue: 1 Pages: 52-59
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Turbulent drag-reduction efficiency of polyisobutylene with three different, very high molecular weights was studied in a build-up closed loop gas oil circulation system. The turbulent mode was produced via a positive displacement gear pump to avoid mechanical degradation of polymer chains during the experimental period. Three molecular weights 2.9*106, 4.1*106 and 5.9*106 g/mol dissolved in reformate were used as additives in order to investigate the effect of molecular weight on drag-reduction rate. The effect of polymer concentration was investigated over a range up to 70 wppm in gas oil flow Reynolds number 8341 to 35747 as well as in 1.25 inch inside pipe diameter. A gradual increase of drag reduction and throughput was achieved by increasing the polymer concentration and gas oil flow rate. Friction factor was calculated from the experimental data. For untreated gas oil pipelining, friction factor values lies near Blasuis asymptotes. While by addition of polymer drag reducer into the flow, the friction factor values were positioned towards Virk maximum drag-reduction asymptotes, noticeably for the highest molecular weight type. Furthermore the investigation showed that the degree of molecular weight is significantly in drag reduction performance. Correlation equations were suggested to predict the effect of flow parameters, concentration, flow rate and finally polymer molecular weight on pressure drop reduction. The results of the correlations showed good agreement between the observed and predicted pressure drop reduction values, with a higher than 97% correlation coefficient

تم دراسة تقليل الاعاقة الاضطرابي في منظومة جريان مغلقة لزيت الغاز بوجود ثلاث اوزان جزيئية مخلتفة من البولي ايزوبيوتيلين. تم الحصول على الجريان الاضطرابي بواسطة مضخة الازاحة الموجية لتجنب الانحلال الميكانيكي لسلاسل البوليمرية. البوليمرات المستخدمة على شكل محاليل في الريفورميت و تمثل مديات مختلفة للوزن الجزيئي, هي 2.9*610 , 4.1*610 و 5.9*610 غرام/الوزن الجزيئي, بهدف دراسة تأثير الوزن الجزيئي على تقليل الاعاقة و زيادة طاقة الضخ في انابيب نقل زيت الغاز.تم اختبار تاثير تركيز البوليمرات المظافة بحدود تصل الى 70 جزء بالمليون وزنا, علاوة على سرعة الجريان المتمثلة بعدد رينولدز بحدود 8341 الى 35747 في انبوب بقطر داخلي 1,25 أنج. تحصل زيادة مستمرة في تقليل الاعاقة بزيادة تركيز البوليمر المضاف, و سرعة الجريان زيت الغاز.تم حساب معامل الاحتكاك من نتائج العملية لتقليل الاعاقة. تقع قيم معامل الاحتكاك لزيت الغاز الغير معامل باتجاه محاذي بلاسيوس. بينما تتجه قيم معامل الاحتكاك نحو محاذي فيرك عند أضفة بوليمرات تقليل الاعاقة, خاصة للنوع ذي الوزن الجزيئي الاعلى. النتائج العملية تشير بوضوح الى تاثير الوزن الجزيئي العالي على فعالية تقيل الاعاقة.تم اقتراح معادلات تخمينية لتقدير تأثير معاملات منظومة الجريان, و هي التركيز, سرعة الجريان و اخيرا الوزن الجزيئي على انخفاض تقليل هبوط الضغط. نتائج المعادلات تؤشر الى توافق كبير بين قيم هبوط الضغط المستحصلة عمليا و المحسوبة من المعادلات التخمينية بنسبة اعلى من 97%.


Article
Drag-Reducing Agent for Aqueous Liquid Flowing in Turbulent Mode through Pipelines
معامل الاعاقة للسوائل التي تتدفق في الوضع المضطرب خلال خطوط الانابيب

Authors: Zainab Y. Shnain زينب يوسف شنين --- Ramzy S. Hamied رمزي صيهود حميد --- Ali M. Hameed علي محمد حميد
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2014 Volume: 10 Issue: 2 Pages: 15-22
Publisher: Baghdad University جامعة بغداد

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Abstract

In this study, mucilage was extracted from Malabar spinach and tested for drag-reducing properties in aqueous liquids flowing through pipelines. Friction produced by liquids flowing in turbulent mode through pipelines increase power consumption. Drag-reducing agents (DRA) such as polymers, suspended solids and surfactants are used to reduce power losses. There is a demand for natural, biodegradable DRA and mucilage is emerging as an attractive alternative to conventional DRAs. Literature review revealed that very little research has been done on the drag-reducing properties of this mucilage and there is an opportunity to explore the potential applications of mucilage from Malabar spinach. An experimental piping rig was used to study the DR properties of the mucilage on water under the effect of varying pipe dimensions and mucilage concentrations. It is shown that these additives can dramatically reduce friction drag provided that the flow is occurring under turbulent conditions. Experimental results also show that DR increases when the mucilage concentration increases.

في هذه الدراسة تم استخلاص الصمغ من السبانخ واختبارها لغرض دراسة خواص تقليل الاعاقة للسوائل المائية التي تتدفق خلال خطوط الانابيب. الاحتكاك التي تنتجها السوائل المتدفقة في الوضع المضطرب من خلال خطوط الانابيب تؤدي الى زيادة في استهلاك الطاقة. ويستخدم معامل الاعاقة مثل البوليمرات, المواد الصلبة العالقة والسطحية للحد من خسائر الطاقة. هنالك طلب على المواد الطبيعية والمواد القابلة للتحلل والصمغية باعتبارها بديلا فعالا . كشفت مراجعة الادبيات السابقة بانه يوجد ابحاث قليلة حول دراسة تقليل الاعاقة للصمغ وكذلك هنالك فرصة لامكانية استكشاف التطبيقات المحتملة للصمغ من السبانخ. تم استخدام انابيب الحفر التجريبية لدراسة خصائص الصمغ على المياه تحت تأثير ابعاد مختلفة للانابيب وكذلك تركيز الصمغ.


Article
Experimental and Theoretical Investigation of Polymeric Drag Reducing Agent in Turbulent Pipe Flow

Author: Izzat Niazzi Slaiman
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2016 Volume: 23 Issue: 2 Pages: 46-53
Publisher: Tikrit University جامعة تكريت

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Abstract

In the present work, the drag reduction effectiveness of water soluble Carboxyl methyl cellulose (CMC) was studied as a function of polymer concentration and flow rate. Drag reduction results were assessed by measuring pressure drop over a one meter test section from the selected pipe. The effect of additives concentration was investigated over a range of 0 – 85 wppm, the solvent (water) flow conditions that were studied included higher flow rates. The experimental work was performed in a constructed re–circulating closed loop system. Maximum drag reduction percent (MDR%) of 17.3 % was obtained by using 85 wppm of CMC. The friction factor was calculated from experimental data with an acceptable average absolute percent Deviation. Correlation equation for fanning friction factor was suggested as a function of Re. The drag reduction results have been correlated based on an modification of a theoretical model available in the literature. The functional form of the model requires knowledge of the velocity profile, ratio of mixing length, friction factor, and the additive concentration as dependent variables.


Article
The Combined Effect of Rib with Single Large Eddy Break Up Devices on Flow and Heat Transfer Characteristic of Turbulent Flow in Rectangular Duct

Authors: Ekhlas Mohammed Fayyedh --- Moayed R. Hasan --- Ali Falah Mohammed
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 1 Pages: 281-291
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

An experimental investigation has been performed to study the effect of combined artificially roughened (ribs) with and without single Large Eddy Break-Up Devices, on flow and heat transfer characteristic of fully developed turbulent flow in rectangular duct. The aspect ratio of rectangular duct is 10, hydraulic diameter 72.72 mm, relative roughness pitch (P/e) 10 and relative roughness height (e/Dh) 0.05. The rib was in the form of circular shape with diameter of (4mm) which was mounted on heated wall of duct at spanwise direction. The experiments have been conducted by varying airflow rate in terms of Reynolds number ranging from 3.2x104 to 6.2x104 and constant heat flux of 600W/m2. The heat transfer and friction factor of the flow for rib and combined method were compared with those of a smooth duct under similar experimental conditions. It has been found that the combined method (rib with single Large Eddy Break-Up Devices) has significant effect on the friction factor and heat transfer with decreasing in friction factor with percent(1.2) and increasing Nusselt number with (4.1). Correlations for Nusselt number and friction factor in terms of (Reynolds number and Large Eddy Break-Up Devices) parameters are found which reasonably correlate the experimental data.


Article
Study the Characterization of Adding Polymer-Surfactant Agent on the Drag Reduction Phenomena in Pipeline Flow System
دراسة خصائص امكانية مزج بوليمر مع مواد تقليل الشد اسطحي وتاثيرها على ظاهرة تقليل الاحتكاك باستخدام نظام انابيب جريان

Author: Sahar A. Dawood سحر عبد الهادي داوود
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2017 Volume: 13 Issue: 2 Pages: 79-89
Publisher: Baghdad University جامعة بغداد

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Abstract

In this study, the effect of carboxylic methyl cellulose (CMC), and sodium dodcyl benzene sulfonate (SDBS) as an aqueous solution on the drag reduction was investigated. Different concentrations of (CMC) and (SDBS) such as (50, 100, 150, 200, 250, 300, 350, 400, 450, and 500 ppm) were used to analyze the aqueous solution properties, including surface tension, conductivity, and shear viscosity. The optimum four concentrations (i.e., 50, 100, 200, and 300 ppm) of fluid properties were utilized to find their effect on the drag reduction. Two different PVC pipe diameters (i.e., 1" and 3/4") were used in this work. The results showed that blending CMC with SDBS gives a good drag reduction percent about (58%) more than using them individually, friction factor decreasing with increasing Reynolds number and gives good agreement with von Karamn equation and maximum drag reduction (MDR) asymptote. Reynolds number, pipe diameter, and polymer-surfactant concentrations were considered as influencing factors. In addition, critical micelle concentration, the onset of drag reduction, and the interactions between the mixed additives were discussed.

في هذا البحث تم دراسة تأثير استخدام كاربوكسيل مثيل سليلوز, وصوديوم دودسيل بنزين سلفونيت بوصفها محاليل مائية على ظاهرة تقليل ألأعاقة لجريان السوائل من خلال الانابيب. تراكيز مختلفة من هذه المواد مثل ( 50, 100, 150, 200, 250, 300, 350, 400, 450, 500 جزء من المليون) تم استخدامها لتحليل خواص هذه المحاليل المحضرة باستخدام هذه المضافات والتي تشمل "الشد السطحي, التوصيلية الكهربائية, واللزوجة" لكل من المضافات المستخدمة منفصلة و ممزوجة وبتراكيز مختلفة. افضل اربعة تراكيز مثل ( ,50100, 200, 300 جزء من المليون) من خواص المحاليل المدروسة تم استخدامها لدراسة تأثيرها على ظاهرة تقليل ألأعاقة لجريان السوائل ,أستخدمت انابيب (PVC) مختلفة الاقطار (1 انج, 3/4 انج ) لدراسة تاثير هذه المضافات منفصلة وممزوجة بوصفها مواد مقللة للاحتكاك عند جريان السوائل خلال هذه الانابيب. النتائج أوضحت امكانية المزج واعطت نسبة تقليل اعاقة حوالي 58 % اعلى مما لو استخدمت منفصلة , تناقص معامل الاحتكاك مع تزايد عدد رينولدز و توافق جيد مع معادلة فون كارامن و MDR asymptote . عدد رينولدز, قطر الانابيب تركيز المضافات كلها تعد عوامل مؤثرة وقد تم مناقشة كل من التركيز الحرج لتكوين المذيلات وبداية ظاهرة تقليل الاعاقة والتداخلات بين المضافات الممزوجة.

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