Table of content

Iraqi journal of mechanical and material engineering

المجلة العراقية للهندسة الميكانيكية وهندسة المواد

ISSN: 20761819
Publisher: Babylon University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

Iraqi journal for mechanical and material engineering is a refereed scientific journal published quarterly by the engineering college/ university of Babylon. It deals with high quality researches in fields of mechanical and material engineering.

Loading...
Contact info

Journal E-mail:
j.mec_mat_eng@yahoo.com
Babylon university/Babylon/Iraq P.O.Box(4)
Tel:++96430245387.(1155)

Table of content: 2018 volume:2018 issue:3

Article
EXPERIMENTAL STUDY OF SOLAR CHIMNEY PERFORMANCE FOR PASSIVE HEATING
دراسة تجريبية لأداء المدخنة الشمسية للتدفئة السلبية

Loading...
Loading...
Abstract

An experimental investigation on solar chimney used for heating under climate of Iraq is carried out. Experiments were conducted on the chimney installed on vertical wall with absorber plate placed at the front side of the air gap. The solar chimney attached to room of dimensions (2.5×1.29×1.07) m. The chimney is studied to measure the effect of the air gap width with constant height of (1.07 m). Three widths are tested, namely, 0.2 m, 0.3 m and 0.4 m. The experimental results showed that the solar chimney can achieve about (13 °C) difference in temperature between indoor and outdoor as well as it gives acceptable difference in partial cloudy days. The results also indicated that the best performance of solar chimney is with 0.3m air gap width.


Article
THERMAL PERFORMANCE OF PARABOLIC TROUGH SOLAR COLLECTOR
ألاداء الحراري لمجمع شمسي نوع قطع مكافئ خطي

Loading...
Loading...
Abstract

This work presents design, instrumented and test of a parabolic trough solar collector under Baghdad climate conditions (of latitude 33.33o N, of longitude 44.4o E). The parabolic trough solar collector consists of: a mirror matrix or tapes which work as reflective surface of (2m *1m), absorber copper tube (receiver), two axis tracking system. Water is used as a heat transfer medium. The setup is tested within clear days from June, to September 2017. The collector heat gain, efficacy and temperature of absorber were presented for absorber five different circulating mass flow rates of (0.15, 0.2, 0.3, 0.4, 0.5) 1pm. The results show that the maximum thermal efficiency of the parabolic trough solar collector is 80.26%. The maximum outlet temperature of the absorber tube reaches 81 oC at the noon when water flows at (0.15) 1pm. The maximum obtained heat gain is (1619W) for (0.5) 1pm flow rate of water.


Article
WIRELESS CONTROL SYSTEM TECHNIQUE FOR EVALUATING THE BUCKLING BEHAVIOR OF 6061-T4 AL-ALLOY
تقنية نظام التحكم اللاسلكي لتقييم سلوك الانبعاج الجانبي لسبيكة الألمنيوم 6061-T4

Loading...
Loading...
Abstract

This research deals with the evaluation of buckling behavior for 6061-T4 aluminum alloy under increasing compressive dynamic loads. Two types of columns, long, and the intermediate columns were used. The number of specimens used in the dynamic axial compression test were 9 samples. (1%) of the length column is the allowable lateral deflection. For the purpose of calculating the initial deflection, the digital dial gauge was used and the instrument was set at a distance of (0.7) of length from the fixed condition for the column. A control system is designed to evaluate the critical buckling and to prevent sample failure. The control system consists of a measuring circuit (transmitter circuit) with a flex sensor installed at 0.7 of the total column length of the column's fixed condition. In addition, the system contains a shutdown circuit (receiver circuit) to switch off the machine at critical load with a mobile phone for the purpose of displaying deflection data. The connection between the transmitter circuit and the receiver wirelessly through the RF sensor and between the transmitter circuit and mobile phone also wirelessly via Bluetooth. The results obtained were experimentally compared with the Perry-Robertson formula. It was found that the Perry-Robertson formula was a good agreement with the experimental results with a safety factor of (1.2) .


Article
INVESTIGATING INDOOR AIR QUALITY AND THERMAL COMFORT USING DIFFERENT VENTILATION SYSTEMS UNDER IRAQI CLIMATE
استقصاء نوعية هواء الغرفة والراحة الحرارية للشاغلين باستخدام منظومات تهوية مختلفة عند ظروف الاجواء العراقية

Loading...
Loading...
Abstract

Computational Fluid Dynamics (CFD) of indoor environment as well as quality considerations are important element in the study of energy consumption, thermal comfort and indoor air quality in buildings. This paper investigate a comparison work between impinging jet, displacement, and mixing ventilation systems for an isothermal and non-isothermal ventilated room for Indoor Air Quality (IAQ) and thermal human comfort under Iraqi climate. For IJV system, draught discomfort is the issue of most concern since it supplies cooled air directly to the occupied zone. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment. The considered factors, supply airflow rate and supply air temperature. RNG K-Ɛ turbulence model was used with the turbulent flow. The second aspect included numerical analyses by adopting ANSYS FLUENT15 code to generate simulation models. A square shaped air supply device was used with [0.1 times room height (h)] outlet terminal height from the foot level end. The IJV system proved more efficient than displacement and mixing ventilation systems. The Air Distribution Performance Index (ADPI) obtained for an isothermal and non-isothermal ventilated room adopting IJV system gave best values (0.80, 0.83) respectively compared with the other two ventilation systems.


Article
EFFECT OF ADDING BORON CARBIDE (B4C) TO POLYMER FOR PRODUCING SURFACE COMPOSITE BY FRICTION STIR PROCESSING
تأثير اضافة كاربيد البورون الى المادة الراتنجية لانتاج مركبات سطحية باستخدام طريقة الخلط بالاحتكاك

Loading...
Loading...
Abstract

Friction stir processing (FSP) is a new solid state technique, it is employed for the improvement of the mechanical properties of a material and the production of surface layer composites instead of conventional processing technologies. This research aims to study the ability of applying Friction Stir Processing (FSP) to modify the surface of high density polyethylene (HDPE) reinforcing by B4C with a particle size of 0.4μm, Groove in the middle of HDPE surface made to fill by B4C. Varity in the groove depth (0.6, 1.2 and 1.8)mm used according to B4C ratio on HDPE substrate particles. Friction stir process was carried out, using tool with cylindrical shape of pin and shoe tool to produce surface layer composite. The effect of processing parameters including rotational and transverse speeds on the mechanical properties of composite layer was studied. Wear test results show a pronounced improvement in wear resistance of HDPE surface through reinforcement additions of B4C at a ratio (5%, 10% and 15% ), where wear rate improved by (60%, 71% and 63%) respectively, as compared with as received HDPE, the surface composite HDPE/B4C have good wear resistance. Hardness test results indicate that the hardness of composite layer reinforced with (5%,10% and 15%) particles improved by( 26%, 35% and 28% )respectively as compared with received HDPE. OM revealed that high tool rotational speed resulted in homogeneous distribution of B4C particles and vice versa.


Article
THE EFFECT OF FINS PERFORATION AND MATERIAL TYPE ON THERMAL PERFORMANCE OF A HEAT SINK UNDER NATURAL CONVECTION
تأثير الشكل الهندسي ونوع المعدن للزعانف على الاداء الحراري لمبدد حرارة تحت الحمل الحراري الطبيعي

Loading...
Loading...
Abstract

An experimental study was done to investigate the effect of fin geometry modification and material type on heat dissipation from a heat sink under natural convection. v-corrugated solid fin and v-corrugated perforated fin were designed for this purpose. Aluminum and Copper metals were selected in designing the fins because their wide application in cooling and heating equipment. Three different voltages 110, 150 and 200 V supplied to the heat sink to study their effects on the fins performance. Each experiment repeats two times to reduce the error and the data recorded after reaching the steady state conditions. The utilization of solid and perforated v-corrugated fins is compared. The results showed that perforated fins dissipated heat more than corresponding solid by 15.4, 34 and 32% for aluminum, and 2.7, 2.1 and 4.3% for copper fin in the three voltages. Also, the results indicated that the heat loss by solid copper fin is greater by 56, 72 and 92% than corresponding solid aluminum fin and for perforated fin case by 38, 31.7 and 51.9 % at 110,150 and 200 V respectively.


Article
STUDYING THE EFFECT OF POLYVINYLPYRROLIDONE (PVP) ON CHARACTERIZATION OF ZNO NANOPARTICLES SYNTHESIZED BY SOL – GEL METHOD.
دراسة تأثير بولي فينل بيروليدون(PVP) على خواص جسيمات لأوكسيد الزنك (ZnO) النانوية المحضر بطريقة السول – جل.

Loading...
Loading...
Abstract

In this paper, studying synthesis zinc oxide nanoparticles (ZnO NPs) via sol - gel method and effect of adding polymer in preparation its solution. Zinc nitrate hexahydrate, Polyvinylpyrrolidone PVP, distilled water and sodium hydroxide (NaOH) were used as precursor materials. Crystallization behavior of the ZnO was studied by X-ray diffraction (XRD). Nanoparticles phases can change from amorphous to wurtzite structure at the calcination temperature (500 °C) and crystallite size by Scherrer’s formula about (21.131) nm for samples prepared with distilled water and (20.035)nm for samples prepared with dissolved PVP. Morphological and structural properties were investigated by scanning electron microscopy (SEM). FT-IR spectra was indicated characteristic absorption bands of ZnO. UV-Vis absorption spectrum was shown a typical spectrum for ZnO nanoparticles. Finally, the results were shown the samples with dissolved PVP has smaller particles size, less agglomeration and narrow distribution but less purity phase when compared with samples prepared with distilled water.


Article
ELECTRODEPOSITION OF COPPER POWDER FROM MIXTURE SULPHATE –CHLORIDE ACIDIC SOLUTION
الترسيب الكهربائي لمسحوق النحاس من خليط كلوريد – كبريتات– محلول حامضي

Loading...
Loading...
Abstract

This paper studies the preparation of Copper powder from Copper Sulphate aqueous solution(CuSO4.5H2O), sulfuric acid (H2SO4) and copper chloride (CuCl2.2H2O)by using the process of electro-deposition. Process of Powder deposition have been investigated for copper powder, it is a fine layer on cathode electrode by using the value of different from current densities (0.12, 0.14, 0.16, and 0.18) A/cm2.as it is noticed the weight of the powder rises with there is of current density. Diffractions of X-ray (XRD) revealed high crystallinity and pure copper powder not contain impurity or oxides. Size of the Crystallite has been measured by Scherrer's Formula about (38.44 -43.161) nm. Optical microscopes have revealed the particles of copper have dendritic shapes. The size of Particles analyzer measured the size of a particle which is about (2.4 – 8.7) μm.


Article
CAD DESIGN AND CONTROL OF TRIPLE INVERTED-PENDULUMS SYSTEM
السيطرة والتصميم المعان للبندول الثلاثي المعكوس

Loading...
Loading...
Abstract

This work is aimed to study the dynamic behavior and control of the triple inverted-pendulum system. A nonlinear dynamic model of the inverted-pendulums fixed on a cart, based on CAD model is developed. The Lagrange equation is used to obtain the nonlinear dynamic models of the system. The dynamic model is then linearized around operating point. An augmented dynamic model using the linearized model is also derived. Two control approaches are used to stabilize the pendulums in vertical position. First approach: State Feedback Control based on the linearized model is used to generate the input force control to stabilize the system. Second approach: Model Predictive Control is designed based on augmented dynamic Model to control the motion of the system. In order to verify the developed model and the chosen controller gains several simulations for different carts’ paths are carried out. Several 3D animations are also presented to verify the usefulness of the designed CAD model and the controllers. As a future work: the 3D model of the triple inverted-pendulum system gives a valuable resource for virtual reality work. Beside, another advanced control approach can be applied on the derived dynamic model.


Article
STUDYING THE IMPROVEMENT OF TENSILE STRENGTH OF LOW ALLOY HIGH STRENGTH STEEL WELDS USING AN ECONOMICAL TECHNIQUE
دراسة تحسين مقاومة شد ملحومات الفولاذ الواطئ السبائك العالي المقاومة باستخدام تقنية اقتصادية

Loading...
Loading...
Abstract

Low alloy steels are particularly used in manufacturing several parts in the heavy engineering industries, agricultural equipment and dies which may be subject to service failure, and thus may need to be repaired by one of the welding processes. The weldability of steels is determined by their sensitivity to cracks that can be prevented by the use of special welding procedures which are often expensive and difficult to use. Manual metal arc welding of low alloy high strength steels was done firstly, using a cheap electrode (OK 46.00), followed by the use of an economical technique which depends on coiling copper wires with different diameters around the cheap electrode. The expensive electrode (OK 73.68) was also used for comparison. Results showed an increase in the tensile strength (712 MPa) and weld joint efficiency (83.8%) when the expensive iron powder low hydrogen covering electrode (OK 73.68) was used. On the other hand, the tensile strength was decreased to (206 MPa) and the weld joint efficiency to (24.2%) when the cheap electrode (OK 46.00) was used. Coiling a (0.6 mm) dia. copper wire around the (OK 46.00) electrode increased the tensile strength and weld joint efficiency to (510 MPa) and (60%) respectively.

Table of content: volume: issue: