UET Peshawar Publications Site (University of Engineering and Technology, Peshawar)
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Hydrodynamic Design of Tidal Current Turbine and the Effect of Solidity on Performance
No full textBlade element momentum (BEM) flow model in conjunction with pattern search optimization algorithm embedded in the National Renewable Energy Laboratory (NREL) tool HARP_Opt was used to design a horizontal axis tidal current turbine (HATCT). The numerical method was validated with the experimental data and a good agreement was achieved. The designed turbine has a 3 bladed rotor of 4 meters diameter and rated mechanical power of 20 kW. Performance metrics of the rotor for steady and uniform flow was simulated at flow speeds from 0.5-3.5 m/s. The turbine achieved its rated power at a tip speed ratio (TSR) 5.7 with a peak CP value of 0.47 and peak thrust of 16.7 kN-m. Additionally, a series of simulations were performed at TSR from 1-10 to obtain performance curve for the turbine at a design current velocity of 1.5 m/s. Effect of solidity on performance was quantified by varying the number of turbine blades. The value of CP increased by 1.5% with increasing the number of blades from 2 to 3. The value of CP further increased by only 0.2% with increase in number of blades from 3 to 4. The value of turbine thrust was minimally effected by increase in the number of blades. However, the value of thrust per blade increased with a reduction in number of blades. The increase in flap moment and thrust per blade with reduction in number of blades could have serious consequences for the structural integrity of the turbine
OPEN MP-BASED PARALLEL AND SCALABLE GENETIC SEQUENCE ALIGNMENT
No full textIn bioinformatics, sequence alignment is a common and insistent task. Biologists align genome sequences to fnd important similarities and dissimilarities in them. Multiple heuristics and dynamic programming based approaches are available for sequence alignment. Smith-Waterman (SW), an exact algorithm for local alignment, is the most accurate of them all. However, the space and time complexity of the SW algorithm is quadratic. It is imperative to use parallelism and distributed computing techniques in order to speed up this process. In this paper, we discuss and evaluate an OpenMP based implementation of SW algorithm. All the experiments have been performed on a Linux based multi-core machine thereby reducing the overall complexity of the SW algorithm from quadratic to linear. The results obtained with various input sequences demonstrate that the parallel version of the SW algorithm runs 2.63 times faster than its sequential counterpart
MODELING, SIMULATION AND FABRICATION OF AN UNDERSHOT FLOATING WATERWHEEL
No full textThis paper presents modeling, simulation and fabrication of an undershot floating waterwheel for power generation for run-of-the-river applications. For the undershot floating waterwheel, analytical modeling and simulation are performed to estimate the optimal design parameters. Moreover, the dependence of output power on various parameters of waterwheel is also investigated during simulations. It is found, during analysis that the water flow velocity is the major factor affecting the output power and due to availability of high flow velocity stream the parameters of the waterwheel, such as, radius and width of wheel can be reduced considerably. For a flow velocity of 1.5 m/s, design estimates for waterwheel producing 1 kW power are obtained with the devised analytical model. The simulations performed for the 1 kW power development, show that a 1 m radius waterwheel with 10 number of blades, each having a width of 1.75 m and height of 0.55 m, are capable of generating the desired power from stream flow velocity of 1.5 m/s. Moreover, a prototype of an undershot floating waterwheel is also fabricated from low weight materials, such as, fber glass and mild steel square tubes. For electrical power generation a DC generator is coupled with the output shaft of the waterwheel. The developed prototype wheel successfully produced a maximum power of 0.6 kW from a water stream flowing at 1.2 m/s in an irrigation channel
RELIABILITY OF LOCALLY MANUFACTURED STEEL BARS AS REINFORCEMENT FOR RC CONSTRUCTION
No full textTheoretical approach based on stochastic methods is employed in order to perform statistical analysis on a very large spectrum of experimental data (the details of which is presented else where) with particular intention to propose the most appropriate values of structural properties of reinforcing steel bars manufactured locally in the country by making use of mainly various types of scrap as raw material. The study is conducted in terms of mean values, standard deviation, coefficient of variation and probability variant by selecting three different parameters i.e. diameter, manufacturer and location. Both lower and upper yield, 0.2 percent proof stress where ever applicable, ultimate stress and elongation have been considered separately for this analysis. Mild plain, deformed and high yield torsteel are the types of steel which have been included. This constitutes a total pool of 355 experimental values for each property. From the results it is observed that the coefficient of variation is quite high almost in every case
SENSITIVITY ANALYSIS OF FAULT LOCATOR PERFORMANCE
No full textFault locators are very important for quick detection and rectifying of fault in electric power system. Its construction depends upon precise valued L,C,R components. In their previous papers the authors have described designed details and performance of the fault locator where as this paper describes analysis of its working ability during unsuitable working conditions of temperature, humidity etc.Due to the delicate construction of the fault locator components and high selectivity requirement for blocking of the resonant frequency together with the narrow band of frequencies around it by the trap circuit and filtration of these by the stack tuner, the fault locator needs (i) accurate designing of its parameters (ii) simulation of its performance (iii) precise manufacturing and (iv) field testing before offering it to its practical commercial use. All these steps are necessary to ensure its reliable performance. Usually all these precautionary steps are enough for successful launching of the product, performance of the fault locator during rough climatic conditions cannot be guaranteed due to distributed capacitance of stack tuner. To reduce chances of failure, the fault locator needs careful analysis to make it withstand the rough and tough hostile conditions of cold, hot and humid nature of outdoor installation.In this paper, authors describe a simple procedure to analyse performance of the fault locator under harsh conditions of the temperature. The result of the test analysis will be discussed and concluded for determination of its usefulness. The analytical test procedure provides clue of stability of the fault locator in changing atmospheric temperature
SIMPLIFIED EQUATION FOR ESTIMATING THE SHEAR CAPACITY OF REINFORCED CONCRETE BEAMS WITHOUT WEB REINFORCEMENT
No full textA summary of a statistical study of shear capacity of non-prestressed reinforced concrete beams is presented. The study was aimed at obtaining a simplified equation by ignoring the effect of M/Vd on shear capacity of R.C beams. All beams used in this study had a shear span/effective depth of at least 2.5 and contained no shear reinforcement. The database used in the statistical analysis comprised 360 beams reported in the literature, including the results of twenty beams, which were cast and tested as a part of this study. An equation is proposed as a result of statistical regression analysis for shear strength of non-prestressed concrete beams without web reinforcement
ELECTRICAL RESISTANCE OF ASPHALT AND ITS APPLICATION IN MEASURING TECHNICAL CHARACTERISTICS OF CONCRETE ASPHALT
No full textIn this research, first it has been discussed how to determine electrical resistance of asphalt and their application in measuring some technical properties of asphalt concrete used in Marshal Test to determine an o mum percentage of bitumen.Using electrical resistance method to determine the resistance and percentage of porosity in cement c Crete has got many applications, and it has been accepted by many concrete technology's researchers.But application of this method used to determine technical parameters of asphalt, for the first time in world has been discussed and evaluated here in Iran. Using this simple, cheap and non-destructive method, \ possible to determined technical characteristics of asphalt by using catalyst such as Salted Water, and also / pared samples can be re-used for another tests.The results of the tests done in this research show that, by increasing percentage of bitumen, the asphalt electrical resistance also increases, and rate of change in Marshal Test's parameters, to the electrical resistance the same as that of Marshal Tests parameters to the percentage of bitumen
A TWO-WAREHOUSE SUPPLY CHAIN NETWORK DESIGN AND OPTIMIZATION WITH CROSS-ROUTE COSTS AND BUDGET, MAXIMUM FLOW AND CAPACITY CONSTRAINTS
No full textSupply chain optimization techniques for modelling the behavior of manufacturing supply chains have been usedfor long in order to allow better planning, minimize total cost and improve efficiency. In this paper, a systematicapproach is presented for the facility placement, optimal production planning and product transportation acrossnetwork arcs. An optimization formulation is developed for the determination of production size, locations of networknodes and optimal supply chain. The objective function considered the minimization of transportation cost, productioncost and the operational costs for the facilities. The incorporation of budget constraint, delivery mode, cross-routecosts, maximum flow by a shipping firm, production capacity of the plants, stocking capacity of owned and rentedwarehouses and traffic factors on the supply routes in the mathematical model further broadened the problem. A casestudy is solved to analyze how the model performs with the changing network characteristics
PTFE THIN FILM COATING ON 316L STAINLESS STEEL FOR CORROSION PROTECTION IN ACIDIC ENVIRONMENT
No full textStainless steels (SS) are the most common materials used in various engineering applications because of theirfine mechanical and excellent corrosion resistance properties in different mediums. 316L SS shows poor corrosionbehavior in HCL. Hard coating is often required for protection of 316L SS from wear and corrosion. In this researchpaper polytetrafluoroethylene (PTFE) was coated on 316L SS by spin coating technique to modify their corrosionresistance in acidic media containing Hydrochloric acid (HCL). The anticorrosion property of the 316L SS and PTFEcoating was studied in 40% HCL by electrochemical corrosion test and potentiodynamic polarization curves at roomtemperature and compared. The morphology of uncoated and coated substrates were examined by scanning electronmicroscopy (SEM) while the compositional analysis performed through energy dispersive x-ray spectroscopy (EDX).The morphology of the coated and uncoated substrates were also studied before and after electrochemical corrosiontest and then compared. The thickness of the coating was also examined well. The result shows the remarkableimprovement in the corrosion resistance of PTFE coating by decreasing the corrosion current density in HCL medi
Analysis of Chip Produced in Free Machining of Ti-6Al-7Zr-3Nb-4Mo-0.9Nd and Ti-5Al-7Zr-7Nb-0.7Nd Alloys
No full textThe use of Titanium and its alloys in modern era can never be discarded. Continuous developments in many industries like aviation and power generation increased its use in many applications, not only because of its chemical properties but also because of its excellent properties including, high strength to density ratio, withstand with high stresses, better fatigue and corrosion properties and ability to resist high temperatures. However, all these properties of this alloy results in poor machinability, hence, make the automatic machining of these alloys nearly difficult. The main limitation of titanium and its alloys is that it produces long chips during machining which tangled around tool, hence; reduce tool life and sometime leads to fracture during conventional turning (CT). In recent days new two alloys are developed named Ti-6Al-7Zr-3Nb-4Mo-0.9Nd and Ti-5Al-7Zr-7Nb-0.7Nd with better performance in machining. These two developed alloys contain 0.9% and 0.7% neodymium by weight, respectively. It produces discontinuous chips during metal cutting, which make possible the automatic machining. It also reduces machining time and increase productivity. Ultrasonically assisted turning (UAT) was used to further improve its machinability. In addition, machinability of both newly developed alloy and Ti-6246 is studied by analyzing chip compression ratio, chip thickness and shearing angle. Overall, chip compression ratio is greater for UAT as compared to CT, which shows improved machinability