Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Jadriyah, Baghdad
Iraq
Mobile:
Email: joengbag@uobaghdad.edu.iq

Table of content: 2015 volume:21 issue:12

Article
Study the Dynamic Behavior of Rotor Supported on a Worn Journal Bearings
دراسة السلوك الديناميكي لدوار مستند على كراسي تحميل متآكلة

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Abstract

In this paper, the effect of wear in the fluid film journal bearings on the dynamic behavior of rotor bearing system has been studied depending on the analytical driven of dynamic stiffness and damping coefficients of worn journal bearing. The finite element method was used to modeling rotor bearing system. The unbalance response, critical speed and natural frequency of rotor bearing system have been studied to determine the changes in these parameters due to wear. MATLAB software was used to find the analytical values of dynamic coefficients of journal bearing. The results of rotor mounted on fluid film journal bearings showed that the wear in journal bearing increases the amplitude of unbalance response and decrease critical speed, stability and the natural frequencies.


Article
Civilizations and Environmental Particulars of Place in Islamic Holy Thresholds in Iraq (Alkadhumain Holy Threshold as a case study)
المحددات الحضارية والبيئية للمكان في عمارة العتبات الإسلامية المقدسة في العراق (العتبة الكاظمية المقدسة –حالة دراسية)

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Abstract

Islamic shrines architecture is one of the Islamic Architectural building types. It is called (Thresholds); (Atabat) in Arabic. Thoroughbred throughout the Islamic world from the east to west. In addition, it carries the style features and peculiarities of uniqueness from the rest of the types of Islamic architecture. By virtue of the particularity of its function as tomb for important person in Islamic history. Islamic shrines architecture has grown and evolved in started from the small shrines, and then taken to widen with the evolution of time in line with the value of the event and the rituals associated with it. Some of them to became centers of large cities of the largest in many parts of the Islamic world. The research problem represented is the insufficiency of information about what roles influences and factors of place (cultural and environmental) in the formation of patterns and relationships space holy Islamic shrines architecture in Iraq. In addition, what the role-played by the inherited urban civilization Iraqi both sides physical & moral support and integration with the concepts and spirit of the Islamic religion, and its rules in construction of architecture. Moreover, presumably Holy Islamic shrines architecture in Iraq are to be studied and its impact on the urban structure and planning in many cities of Iraq mission. In addition to the dimensions of the moral and doctrinal and their impact on society, they have evolved modes of planning over time according to the needs and requirements circumstantial, but the factor of place had a role the basis for the formation of masses and spaces. In addition to the formal role of the Islamic religion and the nature of religious practice in which they are, and the availability of spatial knowledge about the factors that produced the Iraqi architecture, provides a comprehensive picture about the origin of processors and architectural configurations and their source of origin from which it came. Which branded the Islamic holy shrines in Iraq equipped and versatile textural characteristics and detailed thoroughbreds.


Article
Experimental Evaluation Use of Semifluidized Bed Adsorber for the Treatment of P-chlorophenol and O-cresol in Wastewater using Activated Carbon as Adsorbent
تقييم استخدام العمود الماز شبه المميع مختبريا لمعالجة باراكلوروفينول و اورثوكريسول من المياه الملوثة بأستخدام الكاربون المنشط كمادة ممتزة

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Abstract

In the present work the performance of semifluidized bed adsorber was evaluated for removal of phenolic compound from wastewater using commercial activated carbon as adsorbent. P-chlorophenol (4-Chlorophenol) and o-cresol (2-methylphenol) was selected as a phenolic compound for that purpose. The phenols percent removal, in term of breakthrough curves were studied as affected by hydrodynamics limitations which include minimum and maximum semifluidization velocities and packed bed formation in the column by varying various parameters such as inlet liquid superficial velocity (from Uminsf to 8Uminsf m/s), and retaining grid (sometimes referred to as adsorbent loading) to initial static bed height ratio (from 3-4.5). Inlet phenols concentration (50-400 mg/l) and initial pH of the liquid solutions feed (from 4 to 10) were also studied. The experimental semifluidized adsorber unit was designed and constructed in Chem. Eng. labs at Al-Nahrain University (consisted of a QVF glass tube 2.54 cm inside diameter, and 70cm length). The results showed that the initial percent removal of phenolic compounds (P-chlorophenol and o-cresol) decrease with increasing the superficial liquid velocity while the time required reaching equilibrium state decreased. Also it slightly affected with the increase in the retaining grid height and the time required to reach the equilibrium value decreased.


Article
Effect of Metakaolin on the geotechnical properties of Expansive Soil
تأثير الميتاكولين على الخواص الهندسيه للتربه الانتفاخيه

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Abstract

Expansive soil spreads in Iraq and some countries of the world. But there are many problems can be occurred to the structures that built on, so we must study the characteristics of these soils due to the problems that may be caused to these structures which built on these kinds of soil and then study the methods of treatment. The present study focuses on improving the geotechnical properties of expansive soils by treating it Metakaolin(M). Metakaolin (M) has never been used before as an improvement material for stabilizing the expansive soil . Metakaolin is a pozzolanic material. It’s obtained by calcination of kaolinite clay at temperatures from 700°C to 800°C. Kaolin chemical composition is basically aluminous silicates hydrates associated with Mn, Fe, Ca, K, Na. Its crystal has a lattice structure of tetrahedral and octahedral layers with interplanar distance of 7.2 Å. The soil used in the present study can be classified according to the Unified Soil Classification System as clay with high plasticity (CH) .


Article
Calibration and Verification of the Hydraulic Model for Blue Nile River from Roseires Dam to Khartoum City
المعايرة والتحقق للنموذج الهيدروليكي لنهر النيل الأزرق من سد الروصيرص إلى مدينة الخرطوم

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Abstract

This research represents a practical attempt applied to calibrate and verify a hydraulic model for the Blue Nile River. The calibration procedures are performed using the observed data for a previous period and comparing them with the calibration results while verification requirements are achieved with the application of the observed data for another future period and comparing them with the verification results. The study objective covered a relationship of the river terrain with the distance between the assumed points of the dam failures along the river length. The computed model values and the observed data should conform to the theoretical analysis and the overall verification performance of the model by comparing it with another set of data. The model was calibrated using data from gauging stations (Khartoum, Wad Medani, downstream Sennar, and downstream Roseires) during the period from the 1st of May to 31 of October 1988 and the verification was done using the data of the same gauging stations for years 2003 and 2010 for the same period. The required available data from these stations were collected, processed and used in the model calibration. The geometry input files for the HEC-RAS models were created using a combination of ArcGIS and HEC-GeoRAS. The results revealed high correlation (R2 ˃ 0.9) between the observed and calibrated water levels in all gauging stations during 1988 and also high correlation between the observed and verification water levels was obtained in years 2003 and 2010. Verification results with the equation and degree of correlation can be used to predict future data of any expected data for the same stations.


Article
The Role of Transition of Workforce between Companies in Transferring Technology
دور انتقال القوى العاملة بين الشركات في نقل التقنية

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Abstract

The transition of professionals between different sectors is considered as one of sources of acquisition of technology and will lead to add the practical experience to them. This experience depending on different factors like: the scientific degree and practical experience by the professionals, the technology possessed by the transferor sector, the duration that spent by experienced in transferor sector, the type of work performed by professional….etc. The research aims to verify the affect of these factors in technology transfer process. Research reached that the technology transfer process which is depending on the Iraqi competencies in work is unsatisfied level between Iraqi organizations because there are different obstacles behind this. Research diagnosed such obstacles as well as the procedures that followed-up by professionals to serve this process.


Article
Operation of the Iraqi Part of Al-Huweizah Marsh
تشغيل الجزء العراقي من هور الحويزه

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Abstract

Al-Huweizah Marsh is considered as the largest in Iraq. This research aims to maintain the sustainability of Al-Huweizah Marsh under all circumstances and within the limits of the available natural resources from the Iraqi side and the absence of feeding from the Iranian side due to the recent Iranian separation dike along the international boundaries within the marsh. Twelve scenarios have been suggested as a first step to restore the whole marsh. But the uncontrolled Iranian feeders and exiguity of their discharges recently, it was necessary to study only the northern part of the marsh as an alternative case to ensure reasonable amounts of water for the purpose of maintaining and restore the marsh. Hydrological routing model was used to calculate the quantities required to restore the whole marsh, as well as the northern part. In this research, the total dissolved solid (TDS) was adopted as the water quality parameter considering, three concentrations of TDS (1500, 1750, and 2000ppm). A two-dimensional flow mathematical simulation model was prepared using the SMS package (surface water modeling system) where RMA-2 and RMA-4 software’s are used to study the flow and water quality patterns, respectively. In order to improve the water quality in the marsh according to the acceptable water quality determinants and the current conditions, we studied diverting some of Tigris River water, which is one of Shatt-Al-Arab feeders, into the marsh and releasing this amount into Tigris River through Al-Kassara control structure into Shatt-Al-Arab. A significant water quality improvement in the marsh was noticed as a result of mixing 25% or 50% of the Tigris River water which is suppose to go to Shatt Al-Arab. According to the results of this study, it was found that the restoration of the whole marsh cannot be achieved under the current circumstances because of the limited water discharges from Iraqi feeders of the marsh and receding of feeding from Iranian side. The best scenario was that of 3650million cubic meters/year for an area 338km2 and water surface elevation of 3m.a.m.s.l. The results also show that Al-Kassara control structure is unable to pass the required outflow at low level to improve water quality according to the required standard determinants.


Article
Aeroelastic Flutter of Subsonic Aircraft Wing Section with Control Surface
المرونة الهوائية لرفرفة مقطع جناح طائرة مع اسطح السيطرة في سرعة دون سرعة الصوت

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Abstract

Aeroelastic flutter in aircraft mechanisms is unavoidable, essentially in the wing and control surface. In this work a three degree-of-freedom aeroelastic wing section with trailing edge flap is modeled numerically and theoretically. FLUENT code based on the steady finite volume is used for the prediction of the steady aerodynamic characteristics (lift, drag, pitching moment, velocity, and pressure distribution) as well as the Duhamel formulation is used to model the aerodynamic loads theoretically. The system response (pitch, flap pitch and plunge) was determined by integration the governing equations using MATLAB with a standard Runge–Kutta algorithm in conjunction with Henon’s method. The results are compared with previous experimental data. The results show that the aerodynamic loads and wing-flap system response are increased when increasing the flow speed. On the other hand the aeroelastic response led up to limit cycle oscillation when the flow equals or more than flutter speed.


Article
Modeling and Control of Fuel Cell Using Artificial Neural Networks
النمذجة والسيطرة لخلية وقود باستخدام الشبكات العصبية الاصطناعية

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Abstract

This paper includes an experimental study of hydrogen mass flow rate and inlet hydrogen pressure effect on the fuel cell performance. Depending on the experimental results, a model of fuel cell based on artificial neural networks is proposed. A back propagation learning rule with the log-sigmoid activation function is adopted to construct neural networks model. Experimental data resulting from 36 fuel cell tests are used as a learning data. The hydrogen mass flow rate, applied load and inlet hydrogen pressure are inputs to fuel cell model, while the current and voltage are outputs. Proposed model could successfully predict the fuel cell performance in good agreement with actual data. This work is extended to developed fuel cell feedback control system using PID controller to stabilize the fuel cell voltage. Particle swarm optimization technique is used to tune the PID controller gains. The voltage error and hydrogen flow rate are input and the actuator of the PID controller respectively. Simulation results showed that using PID controller with proposed model of fuel cell can successfully improve system performance in tracking output voltage under different operating conditions.


Article
Strengthening of Reinforced Concrete T- Section Beams Using External Post-Tensioning Technique
تقوية العتبات الخرسانية المسلحة ذات مقطع على شكل حرف (T) باستخدام تقنية الشد اللاحق الخارجي

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Abstract

This research is carried out to investigate the externally post-tensioning technique for strengthening RC beams. In this research, four T-section RC beams having the same dimensions and material properties were casted and tested up to failure by applying two mid-third concentrated loads. Three of these beams are strengthened by using external tendons, while the remaining beam is kept without strengthening as a control beam. Two external strands of 12 mm diameter were fixed at each side of the web of the strengthened beams and located at depth of 200 mm from top fiber of the section (dps). So that the depth of strands to overall depth of the section ratio (dps /h=0.8). For each strengthened beams, the strands have been tensioned by using a hydraulic jack with constant stress of 600 MPa. The main parameter conducting in this research is the strengthening length ratio (Ls/L) which is equal to the length of strengthening region (Ls) divided to the length of beam (L), these ratios are 0.83, 0.67 and 0.50. The experimental results showed that this technique for strengthening is efficient for reducing cracks width and increasing first cracking, service cracking and ultimate load capacities. The percentage increasing in first crack loads were 100%, 133% and 167%, for service crack loads (0.3 mm) were 63%, 75% and 88% and for ultimate loads were 78%, 89% and 67% for strengthening length ratios 0.83, 0.67 and 0.50 respectiviely as compared with the control beam.


Article
Modified Grid Clustering Technique to Predict Heat Transfer Coefficient in a Duct of Arbitrary Cross Section Area
طريقة مطورة لتنضيد العقد لغرض التنبؤ بمعامل انتقال الحرارة على طول مجرى ذو مقطع مساحة اعتباطي

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Abstract

A simple straightforward mathematical method has been developed to cluster grid nodes on a boundary segment of an arbitrary geometry that can be fitted by a relevant polynomial. The method of solution is accomplished in two steps. At the first step, the length of the boundary segment is evaluated by using the mean value theorem, then grids are clustered as desired, using relevant linear clustering functions. At the second step, as the coordinates cell nodes have been computed and the incremental distance between each two nodes has been evaluated, the original coordinate of each node is then computed utilizing the same fitted polynomial with the mean value theorem but reversibly. The method is utilized to predict Nusselt number distribution in a hybrid cross section area duct, non-circular non-rectangular, for laminar incompressible flow under Uniform Wall Temperature condition. The results have been compared with the published data and the agreement has been found very well.

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