2021-01-22T13:45:05+03:30
http://ijiepr.iust.ac.ir/browse.php?mag_id=9&slc_lang=en&sid=1
International Journal of Industrial Engineering & Production Research
IJIEPR
2008-4889
2345-363X
10.22068/ijiepr
2006
17
4
Experimental Study and Three-Dimensional Numerical Flow Simulation in a Centrifugal Pump when Handling Viscous Fluids
M. H.
ShojaeeFard
. mhshf@iust.ac.ir
F. A.
Boyaghchi
M. B.
Ehghaghi
ehghaghi@navid.com
In this paper the centrifugal pump performances are tested when handling water and viscous oils as Newtonian fluids. Also, this paper shows a numerical simulation of the three-dimensional fluid flow inside a centrifugal pump. For these numerical simulations the SIMPLEC algorithm is used for solving governing equations of incompressible viscous/turbulent flows through the pump. The k-ε turbulence model is adopted to describe the turbulent flow process. These simulations have been made with a steady calculation using the multiple reference frames (MRF) technique to take into account the impeller- volute interaction. Numerical results are compared with the experimental characteristic curve for each viscous fluid. The data obtained allow the analysis of the main phenomena existent in this pump, such as: head, efficiency and power changes for different operating conditions. Also, the correction factors for oils are obtained from the experiment for part loading (PL), best efficiency point (BEP) and over loading (OL). These results are compared with proposed factors by American Hydraulic Institute (HIS) and Soviet :::union::: (USSR). The comparisons between the numerical and experimental results show good agreement.
Centrifugal pump
Performance
Newtonian fluids
Viscous fluid flow
Correction factors
3D numerical simulation
2006
11
01
53
60
International Journal of Industrial Engineering & Production Research
IJIEPR
2008-4889
2345-363X
10.22068/ijiepr
2006
17
4
Information and Covariance Matrices for Multivariate Pareto (IV), Burr, and Related Distributions
GH.
YARI
yari@iust.ac.ir
M. D
JAFARI
djafari@lss.supelec.fr
Main result of this paper is to derive the exact analytical expressions of information and covariance matrix for multivariate Pareto, Burr and related distributions. These distributions arise as tractable parametric models in reliability, actuarial science, economics, finance and telecommunications. We showed that all the calculations can be obtained from one main moment multidimensional integral whose expression is obtained through some particular change of variables. Indeed, we consider that this calculus technique for that improper integral has its own importance.
gamma and beta functions
polygamma functions; Information matrix
covariance matrix; multivariate pareto models
2006
11
01
61
69
International Journal of Industrial Engineering & Production Research
IJIEPR
2008-4889
2345-363X
10.22068/ijiepr
2006
17
4
A Numerical Method for Backward Inverse Heat Conduction Problem With two Unknown Functions
A.
Shidfar
, shidfar@iust.ac.ir
Ali
Zakeri
This paper considers a linear one dimensional inverse heat conduction problem with non constant thermal diffusivity and two unknown terms in a heated bar with unit length. By using the WKB method, the heat flux at the end of boundary and initial temperature will be approximated, numerically. By choosing a suitable parameter in WKB method the ill-posedness of solution will be improved. Finally, a numerical example will be presented.
Inverse heat conduction
Ill-posed problem
Finite difference method
2006
11
01
71
74
International Journal of Industrial Engineering & Production Research
IJIEPR
2008-4889
2345-363X
10.22068/ijiepr
2006
17
4
A Layer DEA Model for Measuring and Improving the Efficiency in the Presence of Special Decision Making Units
M.R.
Alirezaee
mralirez@iust.ac.ir
S.A
Mir-Hassani
In the evaluation of non-efficient units by Data Envelopment Analysis (DEA) referenced Decision Making Units (DMU’s) have an important role. Unfortunately DMU’s with extra ordinary output can lead to a monopoly in a reference set, the fact called abnormality due to the outliers' data. In this paper, we introduce a DEA model for evaluating DMU’s under this circumstance. The layer model can result in a ranking for DMU’s and obtain an improving strategy leading to a better layer.
Data Envelopment Analysis
Layer Model
Special Decision Making Units
2006
11
01
75
79
International Journal of Industrial Engineering & Production Research
IJIEPR
2008-4889
2345-363X
10.22068/ijiepr
2006
17
4
The Lie Algebra of Smooth Sections of a T-bundle
M.
Nadjafikhah
m_nadjafikhah@iust.ac.ir
H. R.
Salimi Moghaddam
salimi_m@iust.ac.ir
In this article, we generalize the concept of the Lie algebra of vector fields to the set of smooth sections of a T-bundle which is by definition a canonical generalization of the concept of a tangent bundle. We define a Lie bracket multiplication on this set so that it becomes a Lie algebra. In the particular case of tangent bundles this Lie algebra coincides with the Lie algebra of vector fields.
Vector bundle
Lie theory
2006
11
01
81
85