Chittagong University of Engineering & Technology

About: Chittagong University of Engineering & Technology is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Computer science & Renewable energy. The organization has 1200 authors who have published 1444 publications receiving 10418 citations. The organization is also known as: Engineering College, Chittagong & Bangladesh Institute of Technology, Chittagong.

A method of three-dimensional thermo-fluid simulation of the receiver of a standard parabolic trough collector

Abstract: A parabolic trough collector (PTC) is the most proven concentrating collector system for indirect steam generation in solar thermal power plants. The receiver of the collector is fabricated enveloping a metal absorber tube using an evacuated glass tube. Depending on the level of evacuation, the glass envelope reduces the convection heat loss from the tube almost to zero. However, sometimes the envelopes are broken, damaged or removed that causes potential convection loss from an open-to-air receiver tube. On the other hand, the solar irradiance profile around the receiver tube is likely to be highly nonuniform. In order to study the heat transfer mechanism of an exposed receiver tube of a standard PTC under the actual optical and environmental conditions, a 3-dimensional Computational Conjugate Heat Transfer (CCHT) model of the receiver tube was developed. The CCHT model was developed applying finite volume technique of computational fluid dynamics integrating with a verified Monte Carlo ray tracing optical model. The CCHT model was verified extensively, and different heat loss models were developed to investigate the heat loss characteristics. The convection heat loss from the outer surface of the receiver tube was observed very high as it was exposed to a high-temperature gradient with its surroundings. Therefore, it is obvious that the receiver tube should be enveloped and evacuated properly. A well-managed and efficiently operated PTC solar energy field could be the best candidate for sustainable energy management for a sustainable future.

Performance evaluation of reference current extraction methods for hybrid active power filter

Abstract: Active power filter (APFs) has been used to mitigate the harmonic pollution in an electrical network. Reference current estimation is an important part for control of an active power filter. In any inaccuracy in generation of reference current, it yields to poor compensation in load current harmonics. This paper deals with five types of time domain control techniques for real time compensating current for shunt hybrid active power filter. This work also reveals the advantages and disadvantages of the practiced control strategies. The five strategies are analyzed and compared in terms of their performance under balance source and balance load conditions. The comparison and effectiveness of all the methods are based on the theoretical analysis and simulation results obtained with MATLAB/SIMULINK power system block set employing in a three phase three wire network. Here, a three phase six pulse rectifier with R-Load is considered as a nonlinear load.

Ionization of Metastable 2P-State Hydrogen Atoms by Electron Impact for Coplanar Asymmetric Geometry

Abstract: The triple differential cross-sections of First Born approximation have been calculated for ionization of metastable 2P-state hydrogen atoms by electron impact in the asymmetric coplanar geometry. In this study a multiple scattering theory of ionization of hydrogen atoms is used. The latest results of the present method are compared with other calculations. It will be added for new experimental study of ionization of hydrogen atoms in their metastable states.

Collision avoidance technique using bio-mimic feedback control

Abstract: Collision avoidance is a major area of research in vehicle control & safety that involve varying degrees of uncertainty. In general, this problem is challenged with forward collision avoidance technology (FCAT) in cars. An intelligent technique that complements the driving experience must work to avoid collisions generating a smooth trajectory, the vehicle to the intended destination as quickly as possible. Unfortunately, satisfying these requirements with traditional methods proves intractable and forces us to consider bio mimic techniques like Swarm Intelligence. We have developed a bio-tracking based hybrid model which follow the behavior of Ant (tapinoma melanocephalum) and Bat (molossus molossus). In this research, our robot detects obstacle with ultrasound like bat and makes decision to avoid the obstacle like ant. Here an Ultrasonic sound (SONAR) reflection based intelligent control strategy is implemented. Depending on Bat object tracking and Ant motion strategy, we have successfully avoided collision between prototype vehicles and obstacles which was our first goal. This natural sense building up in mechatronics world could make life more secure and find out a perfect relation between theoretical mathematics, nature and engineering.

Fuzzy Features Extraction from Bangla Handwriten Character

Abstract: Character is the fundamental attribute for writing and reading a language. Character recognition is the process to classify the input character according to the predefined character class. Fuzzy logic has proved to be a powerful tool to represent imprecise and irregular patterns. The most tedious job associated with fuzzy logic is the extraction of meaningful features. This paper describes a method to efficiently detect the meaningful fuzzy features including global features, geometric features and positional features from handwritten Bangla character respectively. We have tested our design for different types of Bangla handwritten alphabets in various style and we got successful features extraction results for most of the test cases.