ARPN Journal of Engineering and Applied Sciences                         ISSN 1819-6608
 
 
 
ARPN Journal of Engineering and Applied Sciences                     April 2007  | Vol.2  No.2
Title:

Role of PI and fuzzy controllers in unified power quality conditioner

Author (s):

A. Jaya Laxmi, G. Tulasi Ram Das and K. Uma Rao

Abstract:

Any electrical power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipment is nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. One among the many compensating devices is Unified Power Quality Conditioner (UPQC) which specifically aims at the integration of series-active and shunt-active power filters to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The present work discusses the compensation principle and different control strategies (PI, FUZZY) of the UPQC in detail. The control strategies are modeled using MATLAB/SIMULINK. The performance of UPQC is examined by considering, a thyristor rectifier feeding an RL load (non linear load) that acts as a source of harmonics, to the system of concern. The performance is also observed under influence of utility side disturbances such as sag, swell, flicker and spikes. The simulation results are listed in comparison of different control strategies and for the verification of results.

 
 
 
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Title:

Adsorption of phenol from aqueous solution by water hyacinth ash

Author (s):

M. T. Uddin, M. S. Islam, and M. Z. Abedin

Abstract:

The potential of water hyacinth ash for phenol adsorption from aqueous solution was studied. Batch kinetic and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dosage and pH. The adsorption of phenol decreased with increasing pH. The Freundlich and Langmuir adsorption models were used for the mathematical description of adsorption equilibrium and it was found that the experimental data fitted very well to the Langmuir model. Batch adsorption models, based on the assumption of the pseudo-first-order and pseudo-second-order models, were applied to examine the kinetics of the adsorption. The results showed that kinetic data followed closely to the pseudo-second-order model.

 
 
 
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Title:

Modeling of transportation behavior for coercive measures for car driving in Kuala Lumpur

Author (s):

Abdullah Nurdeen, Riza Atiq O. K. Rahmat and Amiruddin Ismail

Abstract:

The rapid increase of car ownership associated with inadequate public transport has largely contributed to increase traffic congestion, accidents and environmental pollution. A policy proposed to improve public transport and control car ownership simultaneously has become necessary for solving the problems the objectives of this research are to develop mode choice models to expressing car users and public transport users’ behavior and investigate their response to scenario of a reduction in bus and train travel time and travel cost.  In this paper, a survey of 1200 car, bus and train users was conducted in Kuala Lumpur city center. A binary logit model was developed for the three alternative modes, bus, train and car. It was found that travel time, travel cost, gender, age, income level and car ownership are significant in influencing car users’ mode choice behavior. The probability of car drivers shifting to public transport was also examined based on a scenario of a reduction in bus and train travel time and travel cost. Reduction of total travel time and travel cost for the bus and train mode emerges as the most important element in a program aimed at attracting car users towards public transport and away from car mode.

 
 
 
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Title:

Numerical study of opposing mixed convection in a vented enclosure

Author (s):

M. M. Rahman, M. A. Alim, M. A. H. Mamun, M. K. Chowdhury and A. K. M. S. Islam

Abstract:

A numerical study has been performed on mixed convection in a vented enclosure by finite element method. An external fluid flow enters the enclosure through an opening in the left vertical wall and exits from another fixed opening in the right vertical wall. Various inlet port configurations are extensively studied with the change of governing parameters. For mixed convection, the significant parameters are Grashof number (Gr), Richardson number (Ri) and Reynolds number (Re) by which different fluid and heat transfer characteristics inside the cavity are obtained. In present study streamlines, isotherms, average temperature and average Nusselt number of the heated wall are reported for Ri = 0 to 10, Re = 50, 100 and 200; Pr = 0.71, 7.5 and 50 and different inlet position Hi = 0.05, 0.50 and 0.95. From the present analysis it is found that with the increase of Reynolds and Richardson numbers the convective heat transfer becomes predominant over the conduction heat transfer and the rate of heat transfer from the heated wall significantly depends on the position of the inlet port. Higher Nusselt number is observed at very large Prandtl number. Empirical correlations are developed to express the above relation mathematically.

 
 
 
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Title:

Use of Photogrammetry in 3D modeling and visualization of buildings

Author (s):

M. Shashi and Kamal Jain

Abstract:

3D Models of architectural structures are very important in order to study, analyze and also to reconstruct and document these structures. Visualization of these models allows the user to get the photo realistic impression of the structures than graphic based object models. 3D visualization has many applications in the areas of architecture, civil engineering, tourism etc. Normally, field surveys are more accurate than photogrammetric measurements; nevertheless, they involve more personnel and consume a lot of time. Photogrammetry is a measurement technology that can be used for the extraction of 3D points from images. The present paper highlights the project using photogrammetry for accurate 3D modeling and visualization of structures.

 
 
 
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Title:

A finite element method for steady-state natural convection in a square tilt open cavity

Author (s):

Goutam Saha, Sumon Saha and Md. Arif Hasan Mamun

Abstract:

A numerical simulation of two-dimensional laminar steady-state natural convection in a square tilt open cavity has been numerically studied. The opposite wall to the aperture is placed at either isothermal heat source or isoflux heat source, while the surrounding fluid interacting with the aperture is maintained at an ambient temperature. The two remaining walls are assumed to be adiabatic. The fluid concerned is air with Prandtl number fixed at 0.71. The governing mass, momentum and energy equations are expressed in a normalized primitive variables formulation. In this paper, a finite element method for steady-state incompressible natural convection flows has been developed. The streamlines and isotherms are produced, heat transfer characteristics is obtained for Rayleigh numbers from 103 to 106 and for an inclination angles of the cavity ranges from 0º to 60º. The results show that the Nusselt numbers increases with the Rayleigh numbers. Also the average Nusselt number changes substantially with the inclination angle of the cavity while better thermal performance is also sensitive to the boundary condition of the heated wall.

 
 
 
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Title:

Studies on pressure loss in sudden expansion in flow through nozzles: a fuzzy logic approach

Author (s):

R. Jagannath, N. G. Naresh and K. M. Pandey

Abstract:

In this paper pressure loss in suddenly expanded ducts is studied with the help of fuzzy logic as a tool. It is observed that minimum pressure loss takes place when the length to diameter ratio is one and it is seen that the results given by fuzzy logic formulation are very logical and it can be used for qualitative analysis of fluid flow in flow through nozzles in sudden expansion.

 
 
 
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