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: 2008 volume:8 issue:1

Article
NUMERICAL SIMULATION OF THERMAL ENERGY STORAGE SYSTEM USING PHASE CHANGE MATERIAL FOR FREE COOLING OF BUILDINGS

Authors: Dr. Karima E. Amori
Pages: 1-13
Loading...
Loading...
Abstract

A numerical investigation is adopted for a two dimensional thermal energy storage system (TES), employing finite element method to compute the time of charging or discharging energy from a phase change material (PCM) during day or night to utilize it in free cooling of space applying Baghdad Summer climate conditions (ambient temperature). A computer program is developed to analyze the thermal energy unit for different tube diameters, air flow rates and inlet air temperature for both solidification and melting processes. This study shows that utilizing small tube diameter, low flow rates or air inlet temperature near the fusion temperature lead to increase time of phase change process. It was also shown that the time duration of melting is larger than solidification.

Keywords

Free Cooling --- PCM --- Melting --- Solidification --- FEM.


Article
NUMERICAL ANALYSIS OF UNSTEADY NATURAL CONVECTION IN SQUARE CAVITY FILLED WITH A POROUS MEDIA
التحليل العددي لانتقال الحرارة بالحمل الطبيعي غير المستقر

Authors: Khaled Abdul Hussein Al-Farhany
Pages: 14-24
Loading...
Loading...
Abstract

Numerical Analysis of Unsteady Natural convection in square cavity filled with a porous media studied in this paper. The left vertical wall preserves the constant high temperature Th , and the right wall preserves the constant low temperature Tc and both the horizontal walls are insulated . The alternating –direction implicit method ( A.D.I ) is used to solve the non-dimensional governing equations, and finite differences method devoted to Nussele numbers and the horizontal and vertical velocity flow . The results are obtained for the initial transient start up to the steady state, and for Rayleigh number( ). It is observed that the results for average Nusselt number showing an undershoot during the transient period and that the time required to reach the steady state is longer for low Rayleigh number and shorter for high Rayleigh number. ٌِ


Article
HEAT TRANSFER CALCULATIONS OF NON-DEVELOPED STEADY LAMINAR FLOW BETWEEN PARALLEL PLATES
حسابات انتقال الحرارة للجريان الطبائقي المستقر المتطوِّر بين صفيحتين متوازيتين

Loading...
Loading...
Abstract

The objective of the current research is to investigate the developing laminar flow of a Newtonian incompressible fluid and heat transfer in the entrance region of a two parallel plate channel were investigated. The continuity, x-momentum, and energy equations were solved as a steady state in two dimension equations. The dimensionless technique was used. These equations have been represented by finite difference technique. This model has been solved by using the new method of implicit scheme, which would minimize the solution errors. The velocity profile becomes fully developed at approximately , and the temperature distribution becomes fully developed at approximately , as expected. The computational algorithm is able to calculate all the hydrodynamic properties such as velocities. Also the computational algorithm is able to predict all the thermal properties such as the temperature, bulk temperature, and local Nusselt number. The validity of thermal results for constant wall temperature and constant wall heat flux is verified and shows that there is a good agreement between the results of the present numerical solution and the correlation related to it.


Article
HEAT TRANSFER FROM COMPOSITE MATERIAL EXTENDED SURFACES HEAT SINK

Authors: Ali Meer Ali Jasim
Pages: 43-58
Loading...
Loading...
Abstract

The heat transfer from two dimensional unsteady state of composite straight extended surfaces heat sink of different materials is analyzed here by using finite element technique. Galerkin method with linear rectangular elements is used in the present analysis. The effects of conductivity ratio (KR) on the efficiency and the effectiveness of the heat sink are examined ( the efficiency & the effectiveness of the heat sink are increased with increasing of (KR), also the present and non-present of the heat generation through the heat sink is discussed. The effect of the conductivity ratio on the steady state time is discussed here. It can be noted that the increasing of the conductivity ratio (from less than one to greater than one) will reduce the time for reach the steady sate.


Article
EFFECT OF JUTE FIBERS ON THE MECHANICAL PROPERTIES OF EPOXY RESIN
تأثير الياف الجوت على الخواص الميكانيكية لراتنج الايبوكسي

Loading...
Loading...
Abstract

Epoxy resins are widely used in industry by virtue of combinations of favorable characteristics including good mechanical and physical properties, ease of processing and low cost. However, these resins suffer from the disadvantage of brittleness, which limits their use in many applications. In this work, polymeric composites were prepared from epoxy resin reinforced Bi-directionally (0o - 90o) by jute and glass fibers singly and in combination as a hybrid. A comparison is made between the elastic modulus, material toughness and fracture toughness of the composites with those of un-reinforced epoxy to find out the effect of reinforcement on the composites at varying temperatures (0, 25, 40, and 60 Co). Volume fraction for each reinforcement fibers (glass or jute) was 30% but for hybrid composite was (15% glass fibers and 15% jute fibers). The results show that the jute- reinforced laminates have much better properties than the resin alone; but the properties are inferior to those of glass reinforced epoxy. The most appropriate role for the jute fibers is, to use them as filler fibers in combination with glass fibers to get moderate and acceptable mechanical properties during applications. The improvements in mechanical properties (elasticity modulus, material toughness, and fracture toughness) are 623%, 565%, and 593% respectively in comparison with un-reinforced epoxy samples.


Article
استخدام مثبط عضوي لتحسين مقاومة التآكل للفولاذ واطئ الكربون في اوساط تآكلية مختلفة

Loading...
Loading...
Abstract

This research deals with the to study organic inhibitor as aqueous extracts of some parts tree (palm) as corrosion inhibitor to protect low carbon steel in different environments [Tap Water and Hydrochloric Acid (1M)] . Several tests were conducted to evaluate the performance of inhibitor, using weight loss method at different concentrations volume (0.5, 1.5, 3)% by volume. Inhibitor efficiency in tap water and HCl at (3)% concentration of inhibitor reached to (81)% and (92)% respectively. Another test have been carried out to evaluate the corrosion rate by determination of corrosion current by polarization method, where inhibitor efficiency reached to 82.72% in tap water and 89.56% in acidic solution when used (3)% by volume inhibitor. Finally microscope examination tests showed that, the inhibitor is not only active to commercially corrosion inhibitors, but has greatly improved properties such as: low cost, high efficiency and the important properties is easily apply, non-toxic and nonpolluting of the environment.


Article
EFFECT OF INTERFACIAL SHEAR STRESS ON THE MECHANICAL PROPERTIES OF ( srp ) COMPOSITE MATERIAL
دراسة تأثير إجهاد القص البيني على الخواص الميكانيكية لمادة متراكبة ذات ( SRP ) أساس من الايبوكسي مقواة بأسلاك فولاذية

Loading...
Loading...
Abstract

The interface is crucial in controlling composite properties because load is transferred from the matrix to the fiber through this interface. In this paper a study of interface of a composite material which consists of polymer matrix ( Epoxy ) reinforced with high carbon steel wires, ( SRP ). This reinforcement offers high strength and stiffness characteristic at a reasonable cost. Also, the effect of roughness of steel wire on interface and mechanical properties are studied. The bonding force of ( SRP ) composite material with roughened surface increased by about (% 73.3) an increment of flexural capacity by (11.77 %) and the impact energy is increased (60 %) as compared with SRP with polished steel reinforcement wire.

Keywords


Article
MEASUREMENT OF HYDRAULIC RADIUS OF POROUS POLYMER MEMBRANE USING SPECIFIC PERMEABILITY AND POROSITY VALUES
قياس نصف القطر الهيدروليكي لجسم بوليمري مسامي باستعمال قيم النفاذية النوعية والمسامية

Loading...
Loading...
Abstract

The study concern with the measurement of hydraulic radius of imported porous polymer disc of known values (0.8, 1)μm, using specific permeability and porosity data. The study started with the design and built up a permeability unit, with a sample cell specified for this purpose. The followed by leak test and calibration. Volumetric flow rate as a function of pressure difference, across the sample under test, were measured. The slope of the measured values (Q, Δp) at the linear limit, was applied to calculate the mean hydraulic radius; with respect to the air viscosity value, width and Area of the sample. The compared data gives a limit of accuracy in the range of (12 – 16)%.

Keywords

Table of content: volume: issue: