VOLUME 9, ISSUE 5, 2018

 

Cover

Aims and Scope
Editorial Board

Volume 9, issue 5, 2018, pp.i-viii. Download Full Text (PDF)
     
     

1. Natural convection in an air filled cavity with various heat source locations

Ahmed kadhim Hussein, Falah Hassan Naiem

College of Engineering, Mechanical Engineering Department, Babylon University, Iraq.

Abstract: The numerical investigation of the natural convection in a vertical rectangular cavity filled with air is carried by using the finite difference method. The horizontal walls of the cavity are assumed adiabatic. While, the vertical walls are assumed partially heated. Two thermal sources were taken in this study. The hot source was installed in the left sidewall while, the cold was installed on the right sidewall. The sources localized at bottom Ė bottom position. The flow and thermal fields properties are computed for Rayleigh number (103 ≤ Ra ≤ 106), source lengths (0.25 ≤ Ls ≤ 0.75), and aspect ratio (1 ≤ AR ≤ 2) respectively. The results show that, when the Rayleigh number and aspect ratio increase, the fluid flow intensity in the cavity increases also. While, with changing the sources lengths by decrease in the hot source length and the increase in the cold source lengths can be used to improve the flow field. Itís found that the Nusselt number was high with installing the hot source at the top region of the left sidewall while the cold source at bottom region of the right sidewall.

Volume 9, issue 5, 2018, pp.429-448.

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2. Uranium235, 238, 234 soil contamination in Al Tuwaitha nuclear site, using Geomatics techniques

Hisham M. Jawad Al Sharaa, Abdul Razzak T. Ziboon, Abdul Hameed M. Jawad Al Obaidy

Geomatics Eng. Div. Building and Construction Eng. Dep. UOT-Baghdad, Environmental Research Center, University of Technology, Baghdad, Iraq.

Abstract: In this paper, the authors aims to introduce Uranium contamination in Al Tuwaitha nuclear site using Geomatics techniques. The contamination level of Uranium (235, 238, 234 )   , from different soil samples of the  nuclear reactor surrounding areas has investigated and compared to the international standards of UNSCEAR 2000,. The results show that distribution indicates a relatively asymmetrical distribution tailing slightly towards higher concentration. However, the activity level of Uranium in the soil samples exhibits higher variability. U238, 235,234 concentration level exceed the permitted level by (75) times over the UNSCEAR (2000) regulation in spot near Ishtar village and many other uranium contamination inside Al Tuwaitha nuclear research center, location C and Ishtar village. The contaminated area above normal concentration of U sum in soil having about 65% from total contaminated area (0.87 km2) between (0.08-0.2) Bq/g, 23% between (0.2-0.4) Bq/g, 6% between (0.4-0.7) Bq/g, 5% between (0.7- 2.5) Bq/g and 1% between (2.5-4.5) Bq/g as the highest concentration level.

Volume 9, issue 5, 2018, pp.449-454. Download Full Text Article (PDF)
     
     

3. Performance evaluation of a naturally ventilated photovoltaic-thermal (PV/T) solar collector: A case study

Amin Shahsavar1, Pouyan Talebizadeh Sardari2, Sirous Yasseri3, Rohollah Babaei Mahani4

1 Department of Mechanical Engineering, Kermanshah University of Technology, Iran.

2 Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.

3 Department of Mechanical Engineering, Faculty of Engineering, Brunel University, United Kingdom.

4 Director, Belmore Energy Ltd., United Kingdom.

Abstract: The objective of this paper is to design and analyze a naturally ventilated photovoltaic-thermal (PV/T) air collector numerically and experimentally in both glazed and unglazed conditions. To reduce the panelís temperature, a thin metal sheet in the middle of the air channel is used to improve thermal and electrical output of the system. A good agreement is first achieved between the numerical results and the measured data. The validated model is then used to evaluate the effective parameters i.e. solar radiation intensity, channel depth and channel length on air mass flow rate, PV cooling, outlet air temperature as well as thermal and electrical efficiencies. The results show that while the thermal efficiency ranges between 12.21-37.17% throughout the day, the electrical efficiency ranges between 3.23-8.12%.

Volume 9, issue 5, 2018, pp.455-472. Download Full Text Article (PDF)
     
     

4. Evaluation of crest length effect on piano key weir discharge coefficient

Mohammed Baqer N. Al-Baghdadi1, Saleh I. Khassaf2

1 Water Research Center, International Energy and Environment Foundation, Najaf, P.O. Box 39, Iraq.

2 Civil Engineering Department, College of Engineering, University of Basrah.

Abstract: This paper aims to investigate and quantify the effect of changing the crest length of a piano key weir on its discharge coefficient. Empirical equation relating the discharge coefficient with the crest length has been developed based on dimensional analysis by means of statistical computer software. Data were gathered by physical modeling of five 2-unit piano key weir models in an experimental flume 15 m long, 0.3 m wide and 0.45 m deep. Results showed that increasing the crest length has a major influence on the discharge capacity that may reach as much as 100%. The empirical equation estimates the value of discharge coefficient in terms of the dimensionless ratio of (crest length to the weir width), as well as the ratio of (total head to the weir height). It has showed good agreement with experimental results.

Volume 9, issue 5, 2018, pp.473-480. Download Full Text Article (PDF)
     
     

5. Adsorption characteristics of Hydrofluoroolefin on molecular sieves of CMS 5A and Linde 13X as a refrigerant-adsorbent pairs for heat pump applications

M. A. M. HASSAN

Dept. of Mech. Power Eng., Faculty of Eng. (Mattaria), Masaken El-Helmia P. O., Cairo 11718, Egypt.

Abstract: The characteristics of both adsorbent-adsorbate pairs play an important role in several kinds of adsorption refrigeration/heat pump applications. Therefore, the present work aims to investigate the ability of two different molecular sieves, carbon molecular sieve (CMS) 5A and Lined 13X, to absorb Hydrofluoroolefin refrigerant R1234yf on its surface. An experimental testing facility is designed and constructed to measure the adsorption characteristics. Numerous runs were performed with the proposed test facility. Experimental results indicate that the Linde 13X is more suitable than CMS 5A for adsorption of refrigerant R1234yf. In addition, a thermal model based on Dubinin-Astakhov was adopted to predict the adsorption load. The results of the model are very essential in determining the adsorption load at various operating conditions in which the performance of the intermittent heat pump system using the proposed pair could be evaluated. The results agree with the experimental data with a maximum average error of .

Volume 9, issue 5, 2018, pp.481-498. Download Full Text Article (PDF)
     
     

6. A suggested analytical investigation of heat generation inducing into vibration beam subjected to harmonic loading

Diyaa H.J. Al-Zubaidi1, Muhannad Al-Waily2, Emad Q. Hussein1, Maher A.R. Sadiq Al-Baghdadi2

1 University of Kerbala, Faculty of Engineering, Mechanical Engineering Department, Iraq.

2 University of Kufa, Faculty of Engineering, Mechanical Engineering Department, Iraq.

Abstract: The vibration of structure are cusecs generation heat on the machine parts, the heat generation dependent onto the natural frequency supplied on the structure and the materials types (mechanical and thermal properties). Therefore, in this paper investigation the heat generation in the beam due to vibration of beam under frequency excitation (harmonic load excitation), for the beam supported with various boundary conditions, simply supported; clamped supported; and cantilever supported beam. Also, the results included evaluated the heat generation as a function of time with different frequency applied of harmonic load, less and more than the natural frequency of beam. The heat generation due to vibration of beam with time is evaluated by analytical investigation and comparison with numerical study, by using finite element method with CFD package program. The results evaluated are shown the generation heat is decreasing with increasing the frequency of the applied harmonic load. In addition to, the value of natural frequency of beam, dependent is effect on the heat generation of vibration beam, therefore, the supported types of beam are effect of the heat generation due to harmonic load, since the natural frequency of beam is dependent on supported types of beam. The comparison of results between analytical investigation and numerical work had shown the good agreement between with maximum error about (1.36%).

Volume 9, issue 5, 2018, pp.499-514. Download Full Text Article (PDF)
     
     

7. 3D scanning, 3D virtual reality, and 3D printing for Najaf Holy City's cultural heritage and identity

Maher A.R. Sadiq Al-Baghdadi

Center of Preserving of the Cities Heritage and Identity, International Energy and Environment Foundation, Najaf, P.O.Box 39, Iraq.

Abstract: Recently, great development in 3D technologies facilitates digital preservation of cultural heritage. Najaf holy city in Iraq has a rich ancient cultural history, which includes historic groups of buildings, monuments, sites, natural heritage, and energy and sustainability systems in the heritage's buildings. The Center of Preserving of the Cities Heritage and Identity (CPCHI) at International Energy and Environment Foundation (IEEF) founded a first roadmap in preserving Iraqi cultural heritage and identity with 3D scanning, 3D virtual reality, and 3D printing technologies. Part of this project was dedicated to the holy city of Najaf because of its rich cultural heritage. In this part, we intend to share how these three dimensional technologies can be the first step of intervention to save Najaf history. Furthermore, this work highlights the accelerating risks threatening Najaf cultural treasures. We also aim to get our local peoples to think about what we as a community can do to save heritage within our reach, before it is lost to us forever. Not knowing about Najaf heritage is of course a key risk. Moreover, this work is intended to raise awareness of heritage issues in Najaf city by identifying those heritage places, monuments, sites, and the important objects.

Volume 9, issue 5, 2018, pp.515-528. Download Full Text Article (PDF)