eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
1
7
71560
Performance and Emission Characteristics of a Diesel Engine with Cottonseed Oil Plus Diesel Oil Blends
P. R. Reddy
patelramreddy@yahoo.co.in
1
S. N. Mehdi
nawazishmehdi@yahoo.co.in
2
M. Yousuf Ali
yousufonline@yahoo.com
3
Mechanical Engineering, M.J College of Engineering and Technology
Mechanical Engineering, Nawab Shah Alam Khan College Of Engg and Tech
aIn the present study a 4-stroke 5hp diesel engine was tested with Diesel oil plus cottonseed oil blends. The blends in different proportions (10 to 50 percent by volume) were tested at constant speed of 1500 rpm. The said engine is operated at different loads and characteristics like Brake power, Brake thermal efficiency, specific fuel consumption etc. Engine performance for blends resulted in lower brake thermal efficiency. Smoke is also found to increase with the blends. The results of the present experimental investigations reveal that the performance of the blends is comparable with that of diesel. Hence blends can profitably be employed in an existing CI engine without major engine modifications, further it can be an immediate solution for the development of rural areas, and for the emergency use in the event of severe diesel fuel shortage.
https://www.ije.ir/article_71560_371546389b2a1d478feda6218ffd01b7.pdf
Diesel engine
performance
Emission
Blends
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
9
16
71562
Stall Vortex Shedding over a Compressor Cascade (RESEARCH NOTE)
Nima Amanifard
namanif@guilan.ac.ir
1
Mechanical Engineering, University of Guilan
The unstable flow with rotating-stall-like (RS) effects in a rotor-cascade of an axial compressor was numerically investigated. The RS was captured with the reduction in mass flow rate and increasing of exit static pressure with respect to design operating condition of the single rotor. The oscillatory velocity traces during the stall propagation showed that the RS vortices repeat periodically, and the mass flow rate was highly affected by the blockage areas made by stall vortices. The results also showed that large scale vortices highly affects on the generation and growth of the new vortices. An unsteady two-dimensional finite-volume solver was employed for the numerical study which was developed based on Van Leer’s flux splitting algorithm in conjunction with TVD limiters and the κ-є turbulence model was also employed. The good agreement of the computed mass flow rate with the experimental results validates the numerical study.
https://www.ije.ir/article_71562_2311794f6ea5a9e53748d7cab6c7156f.pdf
Stall
Single Rotor
Axial Compressor
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-04-01
18
1
9
19
71563
Axial Compressive Strength of Reinforced Concrete Columns Wrapped with Fiber Reinforced Polymers (FRP)
M. R. Kianoush
kianoush@ryerson.ca
1
M.R. Esfahani
esfahani@ferdowsi.um.ac.ir
2
Civil Engineering, Pyerson University
Civil Engineering, Ferdowsi University of Mashhad
This paper presents the results of a study on the axial compressive strength of columnsstrengthened with FRP wrap. The experimental part of the study included testing 6 reinforcedconcrete columns in two series. The first series comprised three similar circular reinforced concretecolumns strengthened with FRP wrap. The second series consisted of three similar square columns,two with sharp corners, and the other with rounded corners. Axial load and displacement of columnswere recorded during tests using a displacement control test set up. Test results are compared with thevalues calculated using CSA (Canadaian Standard Association) Code provisions and recent proposedequations. It is shown that the FRP wrap increases the strength and ductility of circular columns,significantly. The recent proposed equations correlate well with the test results of circular and squarecolumn with rounded corners. According to the test results, the FRP wrap did not increase thestrength of square columns with sharp corners. However, the square column with rounded cornersexhibited a higher strength and ductility compared to those with sharp corners.
https://www.ije.ir/article_71563_85112cdf9c1f3b026cb5c7e950e535a5.pdf
Column
Concrete
Fiber Reinforced Polymer
Wrap
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
37
43
71570
Experimental Investigation of Boiling and Condensation Heat Transfer of a two Phase Closed Thermosyphon
M. Khoshnoodi
khosh@hamoon.usb.ac.ir
1
M.H. Kalaei
kalaeimh@yahoo.com
2
S.H. Noie
noie@um.ac.ir
3
Chemical & Petroleum Engineering, University of Sistan & Baluchestan
Chemical & Petroleum Engineering, Ferdowsi University of Mashhad
Chemical & Petroleum Engineering, Ferdowsi University of Mashhad
In this paper the heat transfer characteristics of a two-phase closed thermosyphon over a wide range of heat transfer rates, system pressure, aspect ratios and filling ratios were studied. The experiments focused on the boiling and condensation heat transfer characteristics of the thermosyphon. The experimental boiling and condensation heat transfer coefficients inside the thermosyphon were compared with the existing correlations. A good agreement between the experimental results of condensation heat transfer of the thermosyphon and Nusselt’s correlation was obtained. In addition, the optimal working fluid filling and the overall heat transfer coefficient were evaluated for practical operation. Finally, according to poor agreement between the experimental results of boiling heat transfer coefficient and existing correlations, the working conditions were analyzed and a new practical formula (correlation) was presented. The new correlation can be used to predict boiling heat transfer coefficient generally.
https://www.ije.ir/article_71570_1cec38b72797d8e48de98bf0efd1e15b.pdf
Aspect ratio
Two
phase closed thermosyphon
Boiling Heat transfer Coefficient
Condensation Heat Transfer Coefficient
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
45
53
71573
Some Investigation on Bioremediation of Sediment in Persian Gulf Coast (RESEARCH NOTE)
Iran Alemzadeh
alemzadeh@sharif.ir
1
P. Moslehi
moslehi@sharif.edu
2
M. Vossoughi
vosoughi@sharif.edu
3
Chemical Engineering, Sharif University of Technology
Chemical & Petroleum Engineering, Sharif University of Technology
Chemical and Petroleum Engineering, Sharif University of Technology
The amount of petroleum hydrocarbon and heavy metals in the sediment of the Persian Gulf’s shore, at 8 selected stations were determined and showed the maximum of 143.6 and 58.6 mg/kg sediment, respectively, both maximum amounts were related to Emam Hassan zone which is located at 50 kilometers to west Boushehr port. Bioremediation of contaminated sediment were studied in slurry and solid-state fermentation. 8 bacteria types were isolated. Four species Em2, SH, GN1 and GN3 presented maximum PAH removal efficiency. Biodegradation efficiency under slurry conditions was observed after about 45 days, which during this period, naphthalene and phenanthrene showed 73% and 66% removal efficiency respectively. Under solid-state conditions, microbial activity of mixed and pure culture was studied. The results presented that mixed culture due to high ability of different strains for growth, showed higher degradability compared to pure culture, but insufficient mixing under solid state condition resulted in a low mass transfer rate of nutrient which caused reducing cell activity, therefore removal efficiency decreased under solid state condition.
https://www.ije.ir/article_71573_76fbbbbe912f035fde793a496add97d4.pdf
Hydrocarbon Pollutant
Heavy metal
Persian Gulf Coast
Bioremediation
Solid Phase Bioreactor
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
53
64
71575
Resource Investment Problem with Discounted Cash Flows
S.T.A. Niaki
niaki@sharif.edu
1
A. A. Najafi
aa_najafi@yahoo.com
2
Industrial Engineering, Sharif University of Technology
Chemical & Petroleum Engineering, Sharif University of Technology
A resource investment problem is a project-scheduling problem in which the availability levels of the resources are considered as decision variables and the goal is to find a schedule, and resource requirement levels, such that some objective function optimizes. In this paper, we consider a resource investment problem in which the goal is to maximize the net present value of the project cash flows. We call this problem as Resource Investment Problem with Discounted Cash Flows (RIPDCF) and we develop a heuristic method to solve it. Results of several numerical examples show that the proposed method performs relatively well.
https://www.ije.ir/article_71575_ed04746d5dc6a5cd80036a4637fb5845.pdf
Project scheduling
resource investment
Net Present Value
Heuristic methods
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
65
71
71576
Design Requirements for Plate Girders with Bolted Transverse Stiffeners
A. Vasseghi
vasseghi@iiees.ac.ir
1
Civil Engineering, International Institute of Earthquake Engineering
The web of plate girders in bridges are usually reinforced by welded transverse stiffeners in order to improve their shear capacity.Due to problems associated with field welding and fatigue, welded stiffeners are not suitable for retrofitting existing bridges. Bolted stiffeners are a practical alternative for strengthening girders that are expected to experience shear stress in excess of their design shear capacity. This paper presents the results of an analytical study into behavior of plate girders with bolted transverse stiffeners. Based on this study new requirements are developed for designing of such girders.
https://www.ije.ir/article_71576_90c9072314aa9c13b63eeef16ef7d21d.pdf
bridge
Building
Plate Girder
Plate Buckling
Stiffener
Shear strength
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
85
95
71577
Development of an Implicit Numerical Model for Calculation of SUB-and Super-Critical Flows
A.R. Zarrati
zarrati@aut.ac.ir
1
M. R. Hadian
mr_hadian@yazd.ac.ir
2
M. Eftekhari
hasnomail@ije.ir
3
Civil & Environmental Engineering, Amirkabir University of Technology (Tehran Polytec
Civil Engineering, Yazd University
Civil Engineering, Amirkabir University of Technology
A two dimensional numerical model of shallow water equations was developed to calculate sub and super-critical open channel flows. Utilizing an implicit scheme the steady state equations were discretized based on a control volume method. Collocated grid arrangement was applied with a SIMPLEC like algorithm for depth-velocity coupling. A power law scheme was used for discretization of convection and diffusion terms. Underrelaxation factors were introduced in the model to prevent divergence. Momentum interpolation was used in calculating velocities on cell faces to avoid checker board water surface fluctuation in the collocated grid. The model was verified in different cases including complex water surface profiles and hydraulic jumps. The results are compared with experimental and analytical data and the necessary values of under relaxation factors for a converged solution are discussed. No artificial viscosity was required, which is the advantage of the present model.
https://www.ije.ir/article_71577_ea8bbf68785c1c87e1c34f6b1f438b70.pdf
Shallow
Water
Under
relaxation
Sub
Critical
Super
Implicit
Numerical Model
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2005-02-01
18
1
97
114
71578
Solution of Flow Field Equations and Verification of Cavitation Problem on Spillway of the dam
M. N. Mansouri
hasnomail@ije.ir
1
Civil Engineering, Khaje Nasir Toosi University of Technology
The main objective of this paper is to formulate a mathematical model for finding flow field and cavitation problem on dam spillways. The Navier-Stokes Equation has been applied for the computation of pressure and velocity field, free water surface profiles and other parameters. Also, for increasing accuracy of the problem, viscosity effect has been considered. Because of internal flows the effect of gravity forces has been ignored. To have more accuracy the continuity and momentum equations have been transformed to a coordinate system with axis tangent and normal to stream flow.Finite differences has been used to solve equations governing the over flow of dam the spillways. To linearize the nonlinear equations the parameters are expressed in terms of products of last step in the new one. Later the remaining derivatives are with finite differences form. Coefficients of convergence as well as a three diagonal system are used for all the grids points. The cavitation phenomena are discussed after determination of velocity and pressure fields, which cause erosion on the spillway shut and side walls.Also, the different types of cavitations and appropriate solutions were considered and a computer program (MANS) was developed Two examples were solved on this basis and the computed results were compared with experimental results. The results show that for flows up to 4000 m3/sec the condition is good, but for flows higher than this value, the water surface shows high uprising and provisions are needed to resist cavitation at these flows. The results also indicate that at flows about 10899 m3/sec secondary flows dominate near the lateral gates and side walls.
https://www.ije.ir/article_71578_2a494f1f2698cdbcf2d233aa1b40a19b.pdf
Solution of Flow Field
Equation
Cavitation
Spillway
Dam
finite difference
eng
Materials and Energy Research Center
International Journal of Engineering
1025-2495
1735-9244
2004-11-01
18
1
387
390
71554
A Study of Electromagnetic Radiation from Monopole Antennas on Spherical-Lossy Earth Using the Finite-Difference Time-Domain Method
M. Kamyab
kamyab@eetd.kntu.ac.ir
1
K. Paran
pkpkp@eetd.kntu.ac.ir
2
Despatch Group, Khaje Nasir Toosi University of Technology
Electerical Engineering, Khaje Nasir Toosi University of Technology
Radiation from monopole antennas on spherical-lossy earth is analyzed by the finitedifference time-domain (FDTD) method in spherical coordinates. A novel generalized perfectly matched layer (PML) has been developed for the truncation of the lossy soil. For having an accurate modeling with less memory requirements, an efficient "non-uniform" mesh generation scheme is used. Also in each time step, computation is limited to that part of the mesh where the radiated pulse is passing (computational window). In this manner, the values of radiated field at far distances can be obtained directly by the FDTD method. The spatial distribution of radiated field and the influence of the ground screen on monopole's admittance are shown in illustrations.
https://www.ije.ir/article_71554_ff2d8ae5f8e6652eab150fe567c9997a.pdf
FDTD method
Inhomogeneous Media
Electromagnetic Wave Propagation