eng
Iranian Society of Mechanical Engineering
Iranian Journal of Mechanical Engineering Transactions of the ISME
1605-9727
2011-03-01
12
1
5
18
20560
Multi-objective Optimization of Crashworthiness of Cylindrical Tubes as Energy Absorbers
M. Mirzaei
m_mirzaei@aut.ac.ir
1
M. Shakeri
shakeri@aut.ac.ir
2
M. Sadighi
mojtaba@aut.ac.ir
3
S. Seyedi
s_seyedi@gmail.com
4
Islamic Azad University, Damavand
Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
In this article, the multi-objective optimization of cylindrical aluminum tubes under axial impact load is presented.The absorbed energy and the specific absorbed energy (SEA) are considered as objective functions while the maximum crush load should not exceed allowable limit. The geometric dimensions of tubes including diameter, length and thickness are chosen as design variables. The Non-dominated Sorting Genetic Algorithm –II (NSGAII) is applied to obtain the Pareto optimal solutions. A back-propagation neural network is constructed as the surrogate model to formulate the mapping between the design variables and the objective functions. The finite element software ABAQUS/Explicit is used to generate the training and test sets for the artificial neural networks. To validate the results of finite element model, several impact tests are carried out using drop hammer.
https://jmee.isme.ir/article_20560_4c992fa1f50f25c3ff54c758fca5d665.pdf
Cylindrical tube
energy absorption
Neural Networks
Multi-objective optimization
eng
Iranian Society of Mechanical Engineering
Iranian Journal of Mechanical Engineering Transactions of the ISME
1605-9727
2011-03-01
12
1
19
40
20561
Modeling of Upward Subcooled Flow Boiling of Refrigerant-113 in a Vertical Annulus
H. Aminfar
hh_aminfar@tabrizu.ac.ir
1
M. Haghgoo
haghgoo.reza87@ms.tabrizu.ac.ir
2
Mechanical Engineering Department, University of Tabriz , Iran
Mechanical Engineering Department, University of Tabriz, Iran
In this paper, a modified two-fluid model has been adopted to simulate the process of upward vertical subcooled flow boiling of refrigerant R-113 in a vertical annular channel at low pressure. The modified model considers temperature dependent properties and saturation temperature variation and was validated against a number of published low-pressure subcooled boiling experiments. The results show good agreement with experimental data including radial profiles of void fraction, phase velocities and liquid temperature. A sinusoidal axial distribution of wall heat flux was applied as well as constant wall heat flux. Results show that by increasing the wall heat flux, the bubble boundary layer will become thicker and the profiles of axial liquid velocity will gradually depart from those of single-phase flow.
https://jmee.isme.ir/article_20561_30b8fc2cd39127e29dd48a7be4069686.pdf
Two-fluid model
Refrigerant-113
Saturation temperature variation
Subcooled boiling flow
eng
Iranian Society of Mechanical Engineering
Iranian Journal of Mechanical Engineering Transactions of the ISME
1605-9727
2011-03-01
12
1
41
67
20562
Low Velocity Impact on Relatively Thick Rectangular Plate under In-plane Loads Resting on Pasternak Elastic Foundation
Sh. Hosseini Hashemi
shh@iust.ac.ir
1
R. Kalhor
2
, Impact Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
, Impact Research Laboratory, School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
This study deals with the elastic-plastic impact on moderately thick rectangular plate subjected to uniform in-plane compressive loads resting on the Pasternak elastic foundation. The proposed rectangular plates have two opposite edges simply-supported, while all possible combinations of free, simply-supported and clamped boundary conditions are applied to the other two edges. The dimensionless equations of motion of the plate are obtained by applying the Reissner-Mindlin plate theory considering the first-order shear deformation and the rotary inertia effects. The exact closed form solution of the governing equations leading to more accurate result with less calculating time in comparison with the Rayleigh-Ritz method is used to obtain the dynamic response of the plat. The validity of the result is first examined by studying the convergence of the maximum impact force. Then, a comparison of results with those available in literature confirms the excellent accuracy of the present approach. Finally the effects of the dimensionless parameters such as uniaxial and biaxial in-plane loads and the effect of foundation stiffness parameters on force and displacement histories have been examined.
https://jmee.isme.ir/article_20562_2fe6df9557e9a963fab999819ab7efbc.pdf
Low velocity impact
first order shear deformation theory
permanent indentation
in-plane loads
Elastic foundation
eng
Iranian Society of Mechanical Engineering
Iranian Journal of Mechanical Engineering Transactions of the ISME
1605-9727
2011-03-01
12
1
68
85
20563
A Comparative Study on the use of Butyl Esters of Soyabean and Sunflower Oils as Biodiesel Fuel for Compression Ignition Engine
Ajit Pal Singh
singh_ajit_pal@hotmail.com
1
K. Anbumani
2
Department of Mechanical and Vehicle Engineering, Adama Science and Technology University, Adama, Ethiopia
Department of Mechanical Engineering, R.K.M. Engineering College, Kavaraipettai, Gummidipoondi Taluk,Tiruvallur District, Chennai, Tamil Nadu, India
To study the feasibility of using two edible plant oils as diesel substitute a comparative study was made. Oils were exacted from the seeds of soyabean (Glycine Max, Family: Leguminoceae) and sunflower(Helianthus annuus, Family: Asteraceae/Compositeae). Oils were esterified (butyl esters) before blending with pure diesel in the ratio of 10:90, 15:85, 20:80, and 25:75 by volume. Pure diesel was used as control. Studies have revealed that on blending vegetable oils with diesel a remarkable improvement in their physical and chemical properities took place. Cetane number came to be very close to pure diesel. Engine (C.I.) was run at different loads (0, 4, 8, 12, 16, and 20 kg) at a constant speed (1500 rpm) separately on each blend and also on pure diesel. Studies have revealed that soyabean oil at 20% blend with diesel gave best performance in terms of low smoke intensity, emission of HC and NOx. All the parameters tested viz., flash point, total fuel consumption, specific energy consumption, specific fuel consumption, brake thermal efficiency and cylindrical peak pressure were improved. Results have further indicated that at 20% blend engine showed a closer performance to pure diesel. 20% blend of soyabean oil exhibited better performance than sunflower oil blends. However, both the oils at 20% blends with diesel can be used as a diesel substitute. There studies have thus indicated that esterified soyabean oil at 20% blend satisfies the important fuel properties as per ASTM D975 specifications of biodiesel as it lead to the improvement of engine performance and emission characteristics without any modification in engine.
https://jmee.isme.ir/article_20563_de74730c9e97130da970fd05154f8cf1.pdf
Vegetable oil
Biodiesel
Transesterification
Performance analysis
Butyl ester soyabean oil
Butyl ester sunflower oil
Combustion characteristics
eng
Iranian Society of Mechanical Engineering
Iranian Journal of Mechanical Engineering Transactions of the ISME
1605-9727
2011-03-01
12
1
86
108
20564
An Exact Solution for Quasi-Static Poro-Thermoelasticity in Spherical Coordin
M. Jabbari
m_jabbari@azad.ac.ir
1
H. Dehbani
h.dehbani60@gmail.com
2
Postgraduate School, South Tehran Branch, Islamic Azad University, Tehran, Iran
Postgraduate School, Sama Technical and Vocational Training College, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
In this paper the Quasi-Static poro-thermoelasticity model of a hollow and solid sphere under radial symmetric loading condition (r, t) is considered. A full analytical method is used and an exact unique solution of the Quasi-Static equations is presented. The thermal, mechanical and pressure boundary conditions, the body force, the heat source and the injected volume rate per unit volume of a distribute water source are considered in the most general forms where no limiting assumption is used. This generality allows to simulate variety of applicable problems.
https://jmee.isme.ir/article_20564_0475b16d3e9ddc7374067e59c1aae7f1.pdf
Quasi-Static Poro-Thermoelasticity
hollow sphere
Exact solution