Issue 1 - Volume 2

Dec 2019

محتويات الجزء العربي

رئيس التحرير

العوامل المؤثرة في إستكمال مشروعات الإسكان والمرافق المتوقفة بطرابلس

نسرين محمد بن يونس

د. محمد الشريف

تحليل القباب الكروية المتعامدة الخواص ذات إسناد تابت باستخدام نظرية العناصر المحددة المختلطة

م. صبحيه سعد عبده (جامعة جفارة ،كلية الهندسة العزيزيه– ليبيا,األكاديمية الليبية) howida.saad77@gmail.com

أ. د.صالح يحي الباروني (-مدرسة العلوم التطبيقية والهندسية ، قسم الهندسة المدنية والعمارة ،جنزور- ليبيا) saleh.barony@academy.edu.ly

ضوابط التشكيل البصري الخارجية لمباني المتاحف في مدينة طرابلس

نجوى عمران الحصادي (قسم الفنون التشكيلية. تخصص تصميم داخلي. األكاديمية الليبية) alhasadi@gmail.com

مخرجات الصناعة وأثرها على البيئة وصحة الانسان (مصنع سوق الخميس للاسمنت نموذج للدراسة 2018)

د. عبدالحكيم إمحمد خماج Khmag@yahoo.com

م. عبدالله جمعة محمد

English Part-Contents

Editor-in-Chief

Onshore Subsurface Infiltration Galleries Intake for Reverse Osmosis Desalination Plants: A laboratory Scale Investigation

Intake facility is an important system for seawater desalination plant, quantity and quality of the feed water is greatly dependent upon the type of intake. The proper intake system is the first stage of pretreatment process. Infiltration galleries is based on the concept of slow sand filtration where water passes through a filter bed consisting of deferent layers of gravel and sand to a collecting perforated pipes underneath, these galleries are installed on the beach within the intertidal zone of the beach. For this study different combination of bed depths using four different materials with different grain sizes tested at different water heads which are support gravel(G1) with an average diameter of 10mm, engineered gravel(G2) the average diameter 1.81 mm, Engineered sand (ES) the average diameter 0.74 mm and sea sand (SS) the average diameter 0.32 mm. Results revealed that G1 which characterized by large average diameter, high porosity and shape factor have the lowest impact on water flow and head loss while the last layer of SS have the highest impact on water flow and head loss. The effect of water head is minor. The influence of different bed depths for different media materials was investigated; Particle diameter has the main influence on head loss. Several experiments has been carried out using different combinations of bed depths of the used materials, each was constructed and studied separately to quantify a proper filtration rate. Filtration rate is linearly proportional to water head and Sea sand has the highest head loss among the used materials and any depth of the sea sand more than 20Cm has almost the same head loss and reduces the filtration rate

Mukhtar M. Ashur (Libya Academy) ashour60@academy.edu.ly

Munira T. Moamer

Acicular Ferrite Transformation by Isothermal Decomposition in Medium Carbon Vanadium Micro Alloyed Steel

The aim of the present paper is focused on nucleation onset and development morphologies of acicular ferrite and to evaluate microstructure and mechanical properties during isothermal austenite transformation in titanium free micro-alloyed steel. Isothermal treatment was carried out in the temperature range 350 to 450 C. These treatments were interrupted at different times between 2 and 1800 s in order to analyze the evolution of the microstructure. Yield stress was determined by compression testing on samples with final Microstructure. The metallographic evaluation was done by using optical and scanning electron microscopy (SEM) enabled determination of the nucleation onset at all treatments and subsequent on the development of acicular ferrite of isothermally treated titanium free micro-alloyed steel. The results show that during continuous cooling, dominantly acicular ferrite microstructure is formed. Main characteristics of acicular ferrite are intragranular nucleation and strongly disorganized microstructure with a larger ability to deflect cracks. Acicular ferrite is, therefore, widely recognized to be a desirable microstructure due to good mechanical properties. Keywords: Micro alloyed Steel, Isothermal Transformation, Prior Austenite Grain Size, ø5x5mm Compression Test, Grain Boundary and Acicular Ferrite Nucleation. 

Abdulnaser H. Fadel (1Al Zawia University, Faculty of Natural Resources, Al Zawia - Libya) A.fadel@zu.edu.ly

Nenad A. Radovic (Belgrade University, Faculty of Technology and Metallurgy, Kamegijeva 4, 11120 Belgrade, Serbia)

Kamal F. Alhauwari (Al Zawia University, Faculty of Natural Resources, Al Zawia - Libya)

Design, Material and Manufacturing Techniques of a Three Stages Compressor TMM025 Turbojet Engine

The technology of manufacturing a jet engine is a very advanced technology, due to its complicated components which require very advanced technical methods of manufacture and treatment, It has not been established in Libya due to many difficulties which requires special equipment's and alloys with special specifications and standards to withstand the hard operating conditions, not to mention the necessary skilled and experienced labor required to undertake this specialized work. Jet engine(TMM025) has been designed and manufactured in Libya. It has required a tremendous amount of work from many sides and areas, despite the lack of technology and skill needed. Jet engine (TMM025) has been balanced and field tested many times for different inputs and outputs and achieved a very good preliminary results. The success of these tests and the results obtained has made this technology the nucleus of new generation of the strategic industry in Libya, which helped the scientific institutions to understand the technology involved in all of the complicated fields and start to build an advanced technology that can research and develop in this field. The main objective of this research work is to conduct a comprehensive study of a Turbojet engine type (TMM025) with a momentum rate of25daN and rotation speed of 86500rpm, leading to publishing a document that contains restricted and many ways unpublished material in the field of turbojet Engine design and manufacture. TMM025consists of three stage axial compressor, annular combustion chamber with six injectors, axial turbine. Intake and exhaust nozzle modules may be modified for certain design. Turbo Jet Engine TMM025 it can be used as an expendable turbojet engine, such as in Propulsion of weather forecast vehicles, Propulsion of anti-tank missile, Propulsion of anti-ship missile. Can also be reused multiple times, such as in Propulsion of airplane models, Auxiliary propulsion for gliders, demo engines for education. The main task of this paper are as follows; analysis, check out the many different techniques and conditions that must be met when choosing materials and methods of manufacture of all the components of a jet engine and what you need of dynamic balancing process of the rotating parts and heat treatment depending on operating conditions. To find a scientific base and a clear-cut manufacturing operations and future design of the jet turbine engine industry. 

Prof. Dr. Mustafa Jarnaz (The Libyan Academy, Tripoli - Libya) mustafajarnaz@yahoo.com

Dr. Aiman Almahmodi (Tripoli University- Libya) elmahmodi@aerodept.edu.ly

ENG. Taher M. Al-Aabani (Center Welding of Technology _ Tajora -Libya) Taherabani333@gmail.com

MODELLING AND SIMULATION OF MULTISTAGE FLASH (MSF) DESALINATION PLANTS USING TDP, MEDRC AND MSTDP PROGRAMS

Desalination processes are playing a critical role in providing water for domestic and industrial usages in many places over the world. In this study, the benefits of the process modelling utilization in desalination plant design and operation are explored a case study on a real desalination plant is used to demonstrate of the concept. A short-cut method of design and examine operation of Multi Stage Flash (MSF) Process is presented. Three Computer softwares were used and tested to demonstrate simulation of Multi stage Flash (MSF) plant which is operating in an industrial site in Libya. The first software (MSTDP) has been developed by the Authors under the name of '' Modelling and Simulation of thermal desalination plants'' is implemented as Excel Spreadsheet files while the second (TDP) developed by El-Dessouky and Ettouney (TDP - Thermal Desalination Processes) and the last one developed by Middle East Desalination Research Centre (MEDRC). Comparisons and Results obtained from this study are presented along with conclusions and recommendations. 

Salah Al-Hengari (The Libyan Academy, School of Applied Science and Engineering, Chemical and Petroleum Engineering Department, Tripoli – Libya) salah.alhengari@academy.edu.ly

Mohamed El-Bousiffi (Libyan Petroleum Institute, Tripoli – Libya)

Walid El-Moudir (HTC Purenergy Ing. , 001 2305 Victoria Avenue, Regina, SK, S4P 0S7, Canada)

Numerical representation of three stages axial compressor performance map used for small turbojet engine

A numerical representation of three stage axial flow compressor performance map used for a small turbojet engine was developed and verified experimentally. It well known that, the compressor map in the standard format cannot be used directly in a performance calculation program; accordingly in the present work a successful development of non-linear model of a turbojet engine depends largely on the establishing of a consistent compressor performance map that will guaranteeing acceptable accuracy. In the present work the transformation functions of the three stages axial flow compressor performance map for the small turbojet engine are developed to model the non-linear thermodynamic relations obtained from test results

Khaled I. Azzabi (College of engineering technology-Janzour) azzabikh@cetj.edu

Ahmed M. Algadal (College of engineering technology-Janzour) aljedo2000@yahoo.com

Aiman Elmahmodi (Aeraonutical department, Faculty of engineering- University of Tripoli)

Mohamed T. Swei (College of engineering technology-Janzour)

PM3 Calculations on Corrosion Inhibition of Aluminum by phosphonium compounds

We have performed a PM3 calculations on phosphonium as corrosion inhibitors of aluminum with complete optimization of geometries using B3LYP/6-31 G level (d, p) to find a relation between the molecular structure and corrosion inhibition. The electronic properties such as the energy of the highest occupied molecular orbital (HOMO), the energy of lowest unoccupied orbital (LUMO), the energy gap (LUMO–HOMO), quantum chemical parameters such as hardness, softness, the fraction of the electron transferred, and the electrophilicity index. the inhibition efficiency of the investigated phosphonium compounds follows the trend allyl triphenyl phosphonium iodide < allyl triphenyl phosphonium bromide < allyl triphenyl phosphonium chloride < allyl triphenyl phosphonium . 

Zohor M . Elshawi (Department of lab medicine, Higher Institute for Medical Profession – Elzahra) zohorshawe.82@yahoo.com

Salim M. Khalil (Department of Chemistry and Chemical Technology,Faculty of Science, Tafila Technical University)

Manal Ali. Erteeb (Department of Chemistry and Higher Institute Of Sciences And Technology-Azizia) manal.rateeb8503@gmail.com

Structural Optimization of a Composite Wind Turbine Blade (CWTB) for Material and Blade Weight

In order to reduce electrical energy production costs, the size of commercial wind turbines has grown considerably during the past decade. Currently, the largest wind turbine installed gives more power. However, as the size of the wind turbine rotor increases, the structural performance, durability and dynamic stability requirements tend to become more and more challenging to meet. The two main structural performance requirements for wind turbines are sufficient flapwise bending strength to withstand highly rare extreme static and dynamic loading conditions (e.g. 50- year return-period gust or a short-term extreme operating gust), sufficient flapwise bending stiffness to ensure that a minimal clearance is maintained between blade tip and the turbine tower at all times during wind turbine operation. To satisfy the above two extreme operating conditions, several methods have been proposed to evaluate the extreme structural performances of horizontal axis wind turbine (HAWT) blades. One of these method materials basis and weight of wind turbine blade so in this paper two different blade materials were modeled with ANSYS software and the stress ratio and tip deflection under extreme gust loads and the normal wind load are evaluated. The results were compared and presented for different blade materials. 

Prof. Dr. Ramadan A. Almadane (Libyan Academy for Postgraduate Studies Tripoli - Libya) ramadanalmadani@ymail.com

Prof. Dr. Mustafa. E. Jarnaz (College of Engineering Technology-Jounzur Libya) mustafajarnaz@yahoo.com

Mrs Eman Alijaly Daman eman_daman@yahoo.com

EFFECT OF ELEMENT TYPES ON THE RESULT OF FE ANALYSIS

From the very beginning of any analysis tasks the analyst ask him self what type of elements that is suitable for this task ,which element that gives an accurate result .Modern finite element packages have libraries that contain a vast number of elements ranging from simple 1D link element to 3D brick element . These elements increase the capability of finite element (FE) programs to model and solve complex engineering problems. Not only do these elements provide improvement, validity in accuracy of the results but also brought about new challenges which include evaluation of numerical errors of results, setup and execution time as well as large computer memory capacity. The outcome of the analysis is very much dependent of the type of element chosen. The aim of this paper is to investigate the factors influencing the selection of elements in FEA by considering the effects of different types of elements on the results of FEA. A cylindrical pressure vessel is considered for this analysis as an example to demonstrate the importance of element selection .Three different models of the pressure vessel was constructed using ANSYS elements 183 , element 272 and axi har 25 element. The results of these models were compared with the analytical calculation . The FEA results of these models showed good agreement with the theoretical calculation for model meshed with element 183 . Error with element CPT213 and axi har 25 ranged from 12 % to 17% respectively, these might be due to non ax symmetric loading feature of these elements.

Mabrouk M. AlGAMIL (Mech. Engg. Dept., Faculty of Engineering, Sebratha University-Libya) malgamil57@gmail.com

Khalifa M. Ahmed (Mech. Engg. Dept., Faculty of Engineering, Zawia University-Libya) khalifa_online381@yahoo.com

Hassan Guffa (Engineering, Sebratha University-Libya) hassanalgoffa@gmail.com