eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
1
15
10.22115/cepm.2018.122325.1013
64819
مقاله پژوهشی
On the Study of Magnetohydrodynamic Squeezing Flow of Nanofluid between Two Parallel Plates Embedded in a Porous Medium
Gbeminiyi Sobamowo
mikegbeminiyiprof@yahoo.com
1
Olumide Jayesimi
lawrenceunilag@yahoo.com
2
Akindoye Waheed
ljayesimi@unilag.edu.ng
3
Department of Mechanical Engineering, University of Lagos, Akoka, Lagos, Nigeria
Works and Physical Planning Department, University of Lagos, Akoka, Lagos, Nigeria
Department of Mechanical Engineering, Federal University of Agriculture, Abeokuta, Nigeria
A study of magnetohydrodynamic squeezing flow of nanofluid between two parallel plates embedded in a porous medium is presented in this work. The ordinary differential equation which is transformed from the developed governing partial differential equations is solved using differential transformation method. The accuracy of the results of the approximate analytical method are established as they agree very well with the results numerical method using fourth-fifth order Runge-Kutta-Fehlberg method. Using the developed analytical solutions, the parametric studies reveal that when the velocity of the flow increases during the squeezing process, the Hartmann and squeezing numbers decrease while during the separation process, the velocity of the fluid increases with increase in Hartmann and squeezing numbers. Also, the velocity of the nanofluids further decreases as the Hartmann number increases when the plates move apart. However, it is revealed that increase in nanotube concentration leads to an increase in the velocity of the flow during the squeezing flow. The present study will be useful in various industrial, biological and engineering applications.
https://www.jcepm.com/article_64819_f199dcf92697818fee877a2795e4ae41.pdf
Squeezing flow
Nanofluid
Magnetic field
Parallel plates
Differential Transformation Method
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
16
24
10.22115/cepm.2018.136069.1031
82850
مقاله پژوهشی
A Computational Model for Estimating the Compressive Strength of Mortars Admixed with Mineral Materials
Hosein Naderpour
naderpour@semnan.ac.ir
1
Masoomeh Mirrashid
m.mirrashid@semnan.ac.ir
2
Faculty of Civil Engineering, Semnan University, Semnan, Iran
Faculty of Civil Engineering, Semnan University, Semnan, Iran
In this paper, a new computational model is presented to estimate the compressive strength of mortars admixed with Microsilica and a mineral material namely Wollastonite. For this purpose, an equation with fourteen unknown parameters was considered based on a large experimental data, which were published in the literature. The model used five independent parameters including the amounts of the Microsilica, cement, Wollastonite, water and also the age of the specimens (day). For calculating the unknown parameters, the author used artificial neural network method and divided the experimental database into three parts for three phases of the train, validate and test to tune the coefficients of the considered equation. After determining the coefficients, the final equation was validated and tested to estimate the compressive strength of the considered mortars. The results indicated that the proposed equation of this research could be able to determine the compressive strength of mortars admixed with Wollastonite.
https://www.jcepm.com/article_82850_3c4b109e69834b3711a857b435ad49e7.pdf
Mortar
Compressive strength
Calcium inosilicate
Mineral material
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
25
35
10.22115/cepm.2018.147218.1046
82851
مقاله پژوهشی
Elastic Buckling of Single-Stepped Columns with End and Intermediate Axial Loads
Magdy Salama
magdy1000@hotmail.com
1
Department of Civil Engineering, Faculty of Engineering, Kafrelsheikh University, Egypt
Buckling study of single-stepped columns subjected to both intermediate and end axial loads are introduced in this paper. The column understudy is considered as two segments where the upper and the lower parts have different cross section moment of inertia or different material and subjected to intermediate load at the location of the cross section change beside the end load. All the classical end conditions of the studied column are considered in this paper as pinned ends, clamped ends, clamped-free ends and clamped-pinned ends. The analysis is developed using finite element method to study the effect of each parameter may be affect in the buckling loads. These parameters are i) ratio of the intermediate axial load to the end axial load, ii) the intermediate load location as a ratio to the column span and, iii) the ratio of flexural rigidity of lower segment to that of upper one. The obtained numerical results are introduced in many interaction curves to obtain the buckling loads for each end conditions considering the other parameters. A comparison between the obtained results and that of the available theoretical studies shows the accuracy and the simplicity of the present work to get the critical load.
https://www.jcepm.com/article_82851_ff2f6ce5f7b5c3baa1fde4b0362f7ee0.pdf
Stepped column
Intermediate axial loads
Buckling
Finite element method
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
36
52
10.22115/cepm.2018.129584.1024
82842
مقاله پژوهشی
Estimation of Aquifer Transmissivity Using Dar Zarrouk Parameters Derived from Resistivity Soundings on the Floodplain of River Dadin Kowa, Gombe State, Northeastern Nigeria
B. Ankidawa
ankidawa03@yahoo.com
1
J. Ishaku
jmishaku@yahoo.com
2
A. Hassan
abdullahihassan@yahoo.com
3
Department of Agricultural and Environmental Engineering, School of Engineering and Engineering Technology, Modibbo Adama University of Technology, PMB 2076, Yola, Nigeria
Department of Geology, School of Physical Sciences, Modibbo Adama University of Technology, PMB 2076, Yola, Nigeria
Department of Civil Engineering, School of Engineering and Engineering Technology, Modibbo Adama University of Technology, PMB 2076, Yola, Nigeria
The shallow alluvial aquifers on the floodplain are the major sources of water supply for the dry season farming activities. The research is aimed to estimate the aquifer transmissivity of the alluvial formations on the floodplain using Dar Zarrouk Parameters derived from geoelectric soundings. Ten profiles of vertical electric soundings (VES) using schlumberger array method with the aid of a sensitive ABEM Signal Averaging System (SAS) was in the investigation. The results revealed five geoelectric layers on the alluvial formation of the floodplain. There were three, four, five, six and seven layers beneath the alluvial formation. The results were compared with the alluvial floodplain lithologies at each sounding points with resistivity values ranging between 0.98 Ωm to 4,113 Ωm and depths varying from 0.01 to 146 m. The geoelectric sequence of the alluvial formations of the flood plain reveals semi aquifer system. The aquifer hydraulic characteristics indicated that the transverse resistance R ranged between 436.8 Ωm2 to 77,324.40 Ωm2 with a mean value of 11,963.71 Ωm2. The longitudinal conductance S ranged between 0.0026 to 1.792 with an average value of 0.26348. The hydraulic conductivity value across the floodplain ranged between 0.16 m/day to 29.79 m/day with a mean value of 5.597 m/day. The transmissivity values obtained for the various layers range between 1.6 m2/day to 834.1 m2/day with an average value of 128.86 m2/day. The results of the hydraulic head reveal that the floodplain recharges the River. High groundwater potential zone occurs in the southern part of the study area
https://www.jcepm.com/article_82842_4f19b5750a0003e02079c081532d6340.pdf
Alluvial
Aquifers
floodplain
River
Dadin Kowa
Resistivity soundings
Schlumberger
Geoelectric sequence
Dar Zarrouk Parameters
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
53
61
10.22115/cepm.2018.148483.1047
82854
مقاله پژوهشی
Numerical Investigation of the Cooling of Shear Thinning Fluids in Cylindrical Horizontal Ducts
Houari Ameur
houari_ameur@yahoo.fr
1
Youcef Kamla
youcef_kammla@yahoo.fr
2
Djamel Sahel
djamel_sahele@yahoo.fr
3
Department of Technology,Institute of Science and Technology, University Center Ahmed Salhi of Naâma (Ctr Univ Naâma), Po. Box 66, 45000, Algeria
Faculty of Technology, University Hassiba Ben Bouali of Chlef, Algeria
Department of Technical Sciences, University Amar Telidji of Laghouat, Algeria
The present paper is an investigation of the cooling of hot shear thinning fluids flowing through cylindrical pipes. The study is achieved via numerical simulations with the help of the computer code CFX, which is based on the finite volume method to solve the governing equations. The efficiency of two techniques for achieving the cooling process is investigated, namely: the counter flow and the baffling techniques. In the first part and for the first strategy, the hot fluids are cooled by an external turbulent counter flow of a Newtonian liquid. In the second part and in an attempt to enhance the energy efficiency of the heat exchanger system, semi-circular baffles are inserted. We note that two strategies are used in combination in the second part of study. Effects of the flow rates and the pitch ratio of the inserted baffles on the flow and thermal fields are explored. The obtained results show a great enhancement of heat transfer rates when using both strategies in combination.
https://www.jcepm.com/article_82854_394078b30dc17d4d47f1cac53dbea922.pdf
heat exchanger
Cooling of complex fluids
Cylindrical pipe
Semi-circular baffles
Counter flow
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
62
70
10.22115/cepm.2018.141829.1040
82853
مقاله پژوهشی
Modelling and Simulation of Reinforced Concrete Bridges with varying percentages of Shape Memory Alloy Rods
Samson Odeyemi
samson.odeyemi@kwasu.edu.ng
1
Adeola Adedeji
gaiadeji@gmail.com
2
Ph.D. Department of Civil Engineering, Kwara State University, Malete, Nigeria
Prof. Department of Civil Engineering, University of Ilorin, Ilorin, Kwara State, Nigeria
Earthquakes constitute a major problem for mankind resulting in loss of lives and structures. Smart structural materials such as Shape Memory Alloy (SMA) suppress the structural vibration in a structure by adjusting the dynamic performance of the structure. SMA rods are unique for their shape memory effect and super elasticity and have been used as structural reinforcement for earthquake retrofits. This research focused on investigating the appropriate percentage of shape memory alloy and steel reinforcements for the least deflection in the column-capping beam of a 3-span composite Matsurube Bridge in Japan subjected to seismic load. Five different earthquake scenarios were used to obtain the best combination of steel and SMA reinforcement in the columns and capping beam for the best resistance to the earthquake response. Data used for simulations were obtained from the bridge components. It was observed that SMA has a high resistance to seismic loads when combined with steel reinforcement and it is therefore recommended for inclusion in reinforced concrete bridges to serve as means of reducing the effect of earthquakes on structures in earthquake prone areas.
https://www.jcepm.com/article_82853_5797270b579ba8a81ae40066abce31f7.pdf
Shape memory alloy
earthquake
Accelerogram
Matsurube Bridge
Steel reinforcement
eng
Pouyan Press
Computational Engineering and Physical Modeling
2588-6959
2018-10-01
1
4
71
89
10.22115/cepm.2018.141604.1039
82852
مقاله پژوهشی
Seismic Assessment of Steel Moment Frames with Irregularity in Mass and Stiffness
Elahe Chabokan
elahe_ch68@yahoo.com
1
Iman Faridmehr
s.k.k-co@live.com
2
M.sc. Candidate, Islamic Azad University, Dezful branch, Dezful, Iran
Assistant Professor, Girne American University, Kyrenia / TRNC, Cyprus
Irregularity, consider to be one of the main reasons of buildings collapse in recent earthquakes. Irregularity also affects the seismic behavior and maximum capacity of structures. The effect of mass and stiffness irregularity was evaluated in this research using static and dynamic analysis. Three frames with 5, 10 and 15 stories with a 20% and 50% increase in mass of the middle stories and a 20% and 50% decrease in the ground level and middle stories were investigated separately. Maximum drift, first mode period, mass participation coefficient, and base shear force were evaluated using a developed program in MATLAB and SAP2000 based on finite element method. The results showed that changes in mass and stiffness causes a maximum increase of shear force by 14% and 5% in short and tall frames respectively. Maximum drift and the longest period in short frame occurred when the stiffness of ground level was decreased by 50 percent. In addition, such irregularity causes around 85% increase in mass participation coefficient in both short and tall frames.
https://www.jcepm.com/article_82852_a4315e616bce9368f5c1ff787e67a687.pdf
irregular structure
stiffness
response spectrum analysis
time history analysis