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Article
Drag Forces under Longitudinal Interaction of Two Particles

Authors: Sawsan A. M. Mohammed --- Abbas H. Sulaymon عباس حميد سليمون
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2007 Volume: 8 Issue: 2 Pages: 1-4
Publisher: Baghdad University جامعة بغداد

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Abstract

Direct measurements of drag force on two interacting particles arranged in the longitudinal direction for particle ? numbers varying from 10 to are conducted using a micro-force measurement system. The effect of the interparticle distance and Reynolds number on the drag forces is examined. An empirical equation is obtained to dacribe the effect of the interparticle distance (l/d) on the dimensionless drag.


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
Studying the Factors Affecting the Drag Coefficient in Non-Newtonian Fluids

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Abstract

The aim of this research is to study the factors affecting drag coefficient (C ) in non-Newtonian fluids which are the rheological properties ,concentrations of non-Newtonian fluids, particle shape, size and the density difference between particle and fluid .Also this study shows drag coefficient (C ) and particle Reynolds' number (Re ) relationship and the effect of rheological properties on this relationship. An experimental apparatus was designed and built, which consists of Perspex pipe of length of 160 cm. and inside diameter of 7.8 cm. to calculate the settling velocity, also electronic circuit was designed to calculate the falling time of particles through fluid. Two types of solid particles were used; glass spheres and crushed rocks as irregularly shaped particles with different diameters and compared with each other. The concept of equivalent spherical diameter (D ) was used to calculate the diameters of irregularly shaped particles. The flow behavior for Non-Newtonian fluids was represented by Power-Law model. Two types of polymers were used, Carboxy Methyl Cellulose CMC with concentrations of (3.71, 5, 15 and 17.5) g/l and polyacrylamide with concentrations of (2, 4 and 6) g/l. The results showed that the drag coefficient decreased with increasing settling velocity and particle diameters and sizes; and increased as fluid become far from Newtonian behavior and concentrations and the density difference between particle and fluid. The results also showed that the rheological properties of Non-Newtonian fluids have a great effect on the drag coefficient and particle Reynolds number relationship, especially in laminar-slip regime and decreases or vanishes at transition and turbulent-slip regimes. New correlations were obtained which relates drag coefficient with concentrations of polymers and with flow behavior indices for spherical and irregular shaped particles in Carboxy Methyl Cellulose CMC and polyacrylamide solutions.

Keywords

Fluid flow --- Drag --- Settling


Article
Using Microbubbles to Improve Transmission Oil in Pipes

Author: Hussein Hadi Hussein
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2015 Volume: 16 Issue: 2 Pages: 57-60
Publisher: Baghdad University جامعة بغداد

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Abstract

Drag reduction (DR) techniques are used to improve the flow by spare the flow energy. The applications of DR are conduits in oil pipelines, oil well operations and flood water disposal, many techniques for drag reduction are used. One of these techniques is microbubbles. In this work, reduce of drag percent occurs by using a small bubbles of air pumped in the fluid transported. Gasoil is used as liquid transporting in the pipelines and air pumped as microbubbles. This study shows that the maximum value of drag reduction is 25.11%.

Keywords

Drag --- gasoil --- microbubbles --- turbulence


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
ATMOSPHERIC DRAG PERTURBATION EFFECT ON THE SATELLITES ORBITS
تأثير اضطراب الغلاف الجوي للأرض على مسارات الأقمار الصناعية

Author: Abdul_Rahman Hussain Salih عبد الرحمن حسين صالح
Journal: Journal of university of Anbar for Pure science مجلة جامعة الانبار للعلوم الصرفة ISSN: ISSN: 19918941 Year: 2008 Volume: 2 Issue: 2 Pages: 62-72
Publisher: University of Anbar جامعة الانبار

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Abstract

: In this paper the drag perturbation for the law orbit are studded ,Koll-method is suitable to used hear, equation of motion it's solved by numerical integration ;Rang-Kota-method was used ; to find the components of velocity and position and find the orbital parameters with perturbation .Study the effect of drag perturbation on the position , of satellite with time and on perigee , apogee , a ,e and age of satellite, Study the variation of satellite position and age with height we can increase the age of satellite to 40 times by increase the perigee height only 2 times, and by decrease A/m ratio and eccentricity also by rotate in the direction of the earth rotate.

تم في هذا البحث دراسة تأثير كبح الغلاف الجوي للأرض على مدارات الأقمار الصناعية الواطئةواستخدمت طريقة كول لحساب تغير الموضع والسرعة مع الزمن وهي مناسبة. وتحل بالتكامل العدديواستخدمت طريقة رانج –كوتا لإيجاد مركبات الموضع والسرعة، ثم حساب العناصر المدارية بوجود الاضطرابوعمر القمر الصناعي ر ارتفاع a ,e . تم دراسة اضطراب الكبح على مركبات الموضع للأوج والحضيض والقمر على تلك العناصر .وتوصلنا أنه بالإمكان زيادة عمر القمر الصناعي ٤٠ مرة بزيادة ارتفاع الحضيضوالانحراف المركزي وبتدويره باتجاه برم الأرض . A/m مرتين وكذلك تقليل


Article
Drag Force Reduction of Flowing Crude Oil by Polymers Addition
تقليل قوة الاعاقة لجريان النفط الخام بإضافة البوليمرات

Author: Dr.Qaiser Muslim Abid Ali* Talal A. Al-ausi*
Journal: Iraqi journal of mechanical and material engineering المجلة العراقية للهندسة الميكانيكية وهندسة المواد ISSN: 20761819 Year: 2008 Volume: 8 Issue: 2 Pages: 149-161
Publisher: Babylon University جامعة بابل

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Abstract

Studying of effect polymers addition on drag force for flowing crude oil are presented. Two types of Iraqi crude oil have been studied namely, Karkok crude oil with API=35.8 and Basrah crude oil with API=31.2 .Three types of linear polymers (poly isobutylene PIB150K, PIB90K and poly isoprene PIP) are used, the polymers are injected through pumping system at different concentrations rounded between (10-50) ppm with temperatures range of 30o to 50oC. Several experiments were carried out to determine the best concentration of polymer which is satisfied lowest drag force on of crude oil flow rate .The results show that the best execution are realization for PIB150K at 30 ppm and 45oC for two types of crude oil.

في البحث المفدم تم دراسة تأثير أضافة مواد بوليمرية الى عينات من النفط الخام المحلي مختلف الكثافة نفط خام البصرة(API=31.2) ونفط خام كركوك .(API=35.8)،استخدمت ثلاثة انواع من البوليمرات الخطية (البولي ايزوبيوتلين والبولي ايزوبرين) على كفاءة عملية ضخ النفط الخام  تم حقن مادة البولي آيزوبيوتلين PIB بنوعيها PIB150KوPIB90K ومادة الآيزوبرين (PIP) وبتراكيز مختلفة تتراوح بين10 أجزاء بالمليون و50 جزء بالمليون (10-50 ppm) وبمدى حراري يتراوح بين 30-45 oم في منظومة الضخ المختبرية وقد لوحظ تأثير كل من تركيزالبوليمر ودرجة حرارة على معدل سرعة جريان النفط الخام. اظهرت نتائج التجارب العملية ان افضل كفاءة اعطتها مادة البولي آيزوبيوتلين PIB150K وبتركيز لا يتعدى 30 جزء بالمليون ودرجة حرارة 45o م لكلا النوعين من النفط الخام.

Keywords

: Crude Oil --- Polymer --- Drag Force


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
STUDY OF IMPORTANT VARIABLES OF AERODYNAMICS FOR SUBSONIC AIRCRAFT USING ADVANCED AIRCRAFT ANALYSIS SOFTWARE
دراسة أهم المتغيرات الأيرودينامية لطائرة ذات سرعة تحت صوتية باستخدام برنامج AAA

Authors: Israa Yheaa Daood --- Sattar J. Habeeb --- Asaad T. Al-Omran
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2010 Volume: 16 Issue: 1 Pages: 877-893
Publisher: Baghdad University جامعة بغداد

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Abstract

This study presents the important variables of aerodynamics of subsonic aircraft using AAA software, moreover to comprehensive preview of some imperical and mathematical equations where needs in this analysis process. Cruise mission chose for this study comparing with another mission of flight such as Take-off, Climb, Dive & Descent, and Landing according to important of the mission and cruise mission has large rung during the flight mission. These analyses of process submit to more and complex iteration process until we access to correct solution. Lift, drag, and moment coefficients along the lift surfaces such as wing, and horizontal tail were showed. Also this paper explain the effect of flight level, aircraft speed, aspect ratio of lift surfaces on lift curve. Results show that, increase the value of altitude, load factor, aspect ratio leads to increase the value of lift coofficent and decrease the airplane velocity.

الدراسة توضح أهم المتغيرات الأيرودينامية لطائرة ذات سرعة تحت صوتية باستخدام برنامج AAA بالإضافة إلى استعراض شامل لبعض المعادلات التجريبية والرياضية الخاصة في عملية التحليل. الدراسة تمت في مرحلة التحليق للطائرة بسبب أهمية هذه المرحلة, فترة بقاء الطائرة فيها تكون كبيرة مقارنة مع الإقلاع, التسلق, الانحدار, والهبوط حيث تخضع عملية التحليل هذه إلى العديد من الحالات التكرارية المستمرة إلى أن نصل إلى الحل الدقيق. أهم المتغيرات المدروسة كانت توزيع معاملات الرفع, الكبح, العزم على أسطح الرفع المتمثلة بالجناح والذنب الأفقي, بالإضافة إلى دراسة تأثير سقف الطيران, سرعة الطائرة, النسب الباعية لأسطح الرفع على منحني الرفع. أخيرا تم دراسة شكل العلاقة بين معامل الرفع, معامل الكبح عند قيم رقم ماخ مختلفة. النتائج اظهرت أن زيادة مستوي الطيران, معامل الحمل, النسبة الباعية لأسطح الرفع يؤدي إلى زيادة قيم معامل الرفع بينما يحدث العكس في حالة زيادة سرعة الطائرة.

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