12 Articles Published

1. SCHLIEREN VISUALIZATION OF WATER NATURAL CONVECTION IN A VERTICAL RIBBED CHANNEL

Authors: MARIO MISALE , GIOVANNI TANDA , MARCO FOSSA

Abstract: Schlieren techniques are valuable tools for the qualitative and quantitative visualizations of flows in a wide range of scientific and engineering disciplines. In this work, a schlieren technique is applied to visualize the buoyancy-induced flow inside vertical ribbed channels using water as convective fluid. The test section consists of a vertical plate made of two thin sheets of chrome-plated copper with a foil heater sandwiched between them; the external sides of the plate are roughened with transverse, square-cross-sectioned ribs. Results include flow schlieren visualizations and reconstruction of the local heat transfer coefficient distribution along the ribbed surface

Keywords: schlieren, natural convection, ribbed channel, water

Pages: 1 - 5 | DOI: 10.15224/978-1-63248-096-5-08

2. DEVELOPMENT OF ARTIFICIAL NEURAL NETWORK MODEL FOR PERMEABILITY OF HIGH PERFORMANCE CONCRETE

Authors: VAISHALI. G. GHORPADE , BEULAH. M , H. SUDARSANA RAO

Abstract: High performance concrete (HPC) is an engineered concrete possessing the most desirable properties during fresh as well as hardened concrete stages. Permeability is one of the most important parameters to quantify the durability of high-performance concrete. This research was to study the chloride ion permeability of high performance concrete with different mineral admixtures like Fly ash, Silicafume and Metakaolin of different percentages, with varying aggregate-binder ratios (2, 2.5). In addition, on the basis of the experimental data an artificial neural network (ANN) technique is executed to demonstrate the possibilities of artificial neural network formulation for the prediction of chloride permeability as a function of four input parameters : water-cement ratio (0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5), aggregate binder ratio (2,2.5), type of mineral admixtures, percentage replacement of mineral admixtures i.e Fly ash, Silicafume and Metakaolin(0,10,20,30%) as input

Keywords: HPC, Genetic Algorithm, ANN, Chloride Permeability

Pages: 6 - 9 | DOI: 10.15224/978-1-63248-096-5-09

3. INVESTIGATION OF CHANGING PRESSURE AND DRAG COEFFICIENT ON SQUARE CYLINDER WITH DIFFERENT CORNER IN AIR FLOW

Authors: ALI KARGAR , MAJID LOTFI

Abstract: In this research, numerical analysis of corners of square cylinder on following parameters of the turbulence and changing pressure and drag coefficient in air flow has been discussed. Selected models were made of Plexiglas that side length is 15mm and high of this is 400mm. To investigate effect of different corners on following parameters of square cylinder, these cylinders with sharp, rounded and beveled corners are used. Amount of bevel and radius of rounded edges are selected 25.5mm. Type of grid (mesh) around each square is structured and for other parts of solution range, unstructured mesh was used. The result of this research, shows angle of attack and figure of corners of cylinder, causes significant changes in turbulence parameters of square cylinder and value of drag coefficient. Rounding and bevel corners of square cylinder, decrease mean (average) and maximum turbulence in the wakes of cylinder. Drag coefficient by rounding and beveling corners of square cylinder with sharp

Keywords: aerodynamics, wakes of square cylinder, corners of the cylinder, drag coefficient

Pages: 10 - 13 | DOI: 10.15224/978-1-63248-096-5-10

4. VALIDATION OF LBM BASED ON BGK ON POISEUILLE’S FLOW AND VORTEX STREET IN A CHANNEL FLOW

Authors: AKSHAY PRAKASH , ALANKAR AGARWAL

Abstract: The aim of research is to simulate a large scale bioreactor using Lattice Boltzmann method (LBM). Design and scale up a bioreactor is a highly complex process since it involves various physical phenomena occurring together. Computational Fluid Dynamics (CFD) has been developed over the years to simulate complex phenomenon occurring in a bioreactor and can make up for the shortcomings associated with traditional scale-up methods. It allows the simulation of all the relevant physics like species and thermal transport along with millions of bubbles. Due to various recent advances in numerical techniques and computer hardware (particularly the Graphical Processing Units-GPUs, aimed at number crunching applications), the simulation of an industrial scale reactor is now possible in reasonable time. While conventional pressure based solvers, such as the SIMPLE algorithm and its variants, do not scale well with large number of processors and may not utilize the GPUs cores effectively, Lattice

Keywords: Lattice Boltzmann Method, Computational Fluid Dynamic, Bhatnagar-Gross-Krook, Von karman vortex street

Pages: 14 - 18 | DOI: 10.15224/978-1-63248-096-5-11

5. FULL-SCALE TESTING OF A REINFORCED CONCRETE FRAME UNDER FIRE

Authors: EUN MI RYU , HEE SUN KIM , HYUN AH YOON , JI YEON KANG

Abstract: Most experimental studies have been performed to investigate the fire resistance of a single member, beam, column, wall, and slab. However, a limited number of experimental studies have been performed on full-scale structures, especially reinforced concrete (RC) structures. This paper aims at investigating temperature distribution on a full-scale RC structure under fire. RC structure is constructed 2,400(width) × 1,000 (length) × 2,100 (height) mm and consists of one column, two beams, two walls, and two slabs. This specimen is heated on one side with ISO-834 standard time-temperature curve for 2 hours and temperature distributions during the test are measured using thermocouples inside the structure. To investigate the relationship of temperature distributions between full-scale structure and a single member, the experimental results of full-scale structure are compared with those of a single member throughout the other experimental studies.

Keywords: Fire, Full-scale testing, Normal strength concrete, Reinforced concrete frame, Temperature distribution

Pages: 19 - 23 | DOI: 10.15224/978-1-63248-096-5-12

6. DESIGN OF HEAT PIPE HEAT EXCHANGER WITH PLATE FINS BY TWO METHODS LMTD AND ε-NTU

Authors: ALI KARGAR , MAJID LOTFI

Abstract: In this study, the effective factors on the heat transfer and pressure drop in heat pipe heat exchanger design based on the LMTD and effectiveness-NTU has been investigated. Increasing fuel cost and energy conservation, fuel consumption and also, pollution air are the most important consideration to be taken in new heat exchanger design, and modern compact heat exchangers. This paper describes a theoretical method to the design and performance of heat pipe heat Exchanger. Design of heat pipe heat exchanger for identifying of the principal parameters, which can optimize the performance of heat exchanger. Heat pipe heat exchanger efficiency with copper pipes is 10% higher than steel but steel pipe for strength and its ability to heat recovery of hot gases is preferred. Increasing the number of rows of tubes will increase efficiency. The largest diameter pipes and increasing the number of fins improved efficiency. Pressure drop of the heat pipe heat exchanger placed as heat recovery unit

Keywords: Heat Pipe, Design of Heat Exchanger, LMTD and ε-NTU method, Pressure Drop

Pages: 24 - 27 | DOI: 10.15224/978-1-63248-096-5-13

7. CHLORIDE PENETRATION AND SULFATE RESISTANCE OF CONCRETE INCORPORATING NANO-SILICA (NANO-SIO2), MICRO-SILICA (MICRO-SIO2) AND FLY ASH

Authors: RANJITH DISSANAYAKE , THUSHARA PRIYADARSHANA

Abstract: In this study, effects of nano-silica (nano-SiO2), micro-silica (micro-SiO2) and fly ash on chloride penetration, sulfate resistance and water permeability were investigated based on the results of electrical indication of concrete’s ability to resist chloride iron penetration test (ASTM standard C1202-10) and length change of hydraulic cement mortars exposed to a sulfate solution test (ASTM standard, C1012-02). The addition of nano-silica (nano-SiO2), micro-silica (micro-SiO2) and fly ash in concrete causes a remarkable reduction in chloride iron permeability. These effects may be due to primarily to microstructural changes both in the cement paste phase and in the interracial zone around aggregates. In concrete with nano-silica (nano-SiO2) and micro-silica (micro-SiO2), Nano-SiO2 can behave as nucleus tightly bond with cement hydrates. A stable gel structures can be formed and the mechanical properties of hardened cement paste can be improved when a smaller amount of these materials

Keywords: nano-silica, micro-silica, durability of concrete, chloride penetration, sulfate resistance

Pages: 28 - 32 | DOI: 10.15224/978-1-63248-096-5-14

8. THEORETICAL AND EXPERIMENTAL BEHAVIOR OF REINFORCED CONCRETE BEAMS UNDER TORSION

Authors: ABDULKADIR CUNEYT AYDIN , BARIS BAYRAK

Abstract: In this study, behaviour of reinforced concrete beams under pure torsion have been investigated. Test series comprise of 12 units of reinforced concrete beams of 250x300x1500 mm. Stirrup spacing was selected 80 mm and 100 mm, concrete class was selected C20 and C40. The test specimens divided into 4 groups. In the test specimens, 16 mm was used for the longitudinal reinforcement, 8 mm was used for the stirrup and convensional concrete was used. The torsioal moment capacity, rotation angles of the concrete beams was investigated. In addition to this, the releationship between the torsional moment and rotation angles, the failure torsional moment, the cracks occuring at the beams were examined. For the theorically formula of torsional moment capacity, American Concrete Institute (ACI), Eurocode-2, Turkish Standart, elastic, plastic and skew-bending theories were used. Experimental results and theoretical results of the torsional moment capacity and the failure torsional moment were compa

Keywords: torsion, unit rotation angle, elastic theory, plastic theory, skew-bending theory

Pages: 33 - 36 | DOI: 10.15224/978-1-63248-096-5-15

9. SEISMIC PERFORMANCE FOR A CONCRETE SCHOOL BUILDING DESIGNED BEFORE THE BUILDING STANDARD ACT REVISED

Authors: MAMORU KAWASAKI , TETSUYA OHMURA

Abstract: This paper described the seismic performance of a concrete school building built in 1973, and numerous similar school buildings are being used even now in not only local area but also urban area in Japan.The Japanese building standard act was revised in 1981 considered non-linearity. However, a number of buildings built before 1981 are existing, seismic evaluations for those building have actively been assessed based on the seismic evaluation standard1) published by The Japan Building Disaster Prevention Association after especially 1995 Kobe Earthquake.In practical seismic evaluation works, it is relatively simple and easy to make models of general buildings, but unconventional frames are complex such as a staircase or a frame with level different girders.The flexible length of the column with a wall having an opening or level different girders are generally assumed as the inside measurement height. The modeling way would be simply, however, the seismic behavior of the unconventional

Keywords: seismic performance, dynamic analysis, concrete building, short column, level diferent girder

Pages: 37 - 40 | DOI: 10.15224/978-1-63248-096-5-16

10. ANALYTICAL MODEL OF OVERLAPPED FRP BARS EMBEDDED IN CONCRETE UNDER HIGH TEMPERATURE

Authors: ALI ZAIDI , HIZIA BELLAKEHAL

Abstract: Fiber reinforced polymer (FRP) bars have become progressively more used in civil engineering because of their excellent properties with respect to steel bars, mainly, their corrosion resistance. The designers generally adopt over-reinforced sections to avoid a sudden failure mode of FRP bars. Therefore, the overlap of the bars is omnipresent. However, under high temperature, the area of overlap may be regarded as a zone of radial stresses concentration generated by pressure caused by the thermal expansion of both bars. The aim of this study is to develop an analytical model allows to investigate the thermal stress and strain distributions in FRP bars and in concrete of beams reinforced with two overlapped FRP bars. By varying the ratio of concrete cover thickness to FRP bar diameter (c/db) from 1 to 3.2 and the temperature variation from 0°C to 60°C. The analytical model is based on the linear elasticity. Analytical results are compared with those obtained from numerical model using AD

Keywords: Analytical model, Numerical simulation, Temperature, FRP bars, concrete cover thickness, Transverse stresses.

Pages: 41 - 45 | DOI: 10.15224/978-1-63248-096-5-17

11. MODELING OF STORAGE MODULUS OF GRAPHENE-EPOXY NANOCOMPOSITES

Authors: ALPEREN ACAR , DENIZ UZUNSOY , OZGEN COLAK CAKIR

Abstract: In this work, the storage modulus of epoxy and graphene-epoxy nanocomposites are modeled using a temperature and rate dependent modulus formulation. The stiffening effect of reinforcements is included to the elastic modulus formulation for the modeling of nanocomposite materials. Simulation results are compared to experimental data from Acar et al.

Keywords: graphene, epoxy, storage modulus.

Pages: 46 - 49 | DOI: 10.15224/978-1-63248-096-5-40

12. VEHICULAR OCCUPANT STAR RATING OF HIGHWAY BY IRAP METHODOLOGY

Authors: SANDEEP K PRUSTY , RASHMI R BARIK , SOUMYA R NAYAK

Abstract: The ever increasing road accidents prompted for road safety assessment in order to assess the accident potential and suggest measures in order to diminish the accident potential. This paved the way for the foundation of Road Assessment Programmers (RAP) which performs systematic analysis of road segments to rectify the safety shortcomings and mitigate. This study uses the iRAP methodology for star rating and encompasses various road attributes (i.e. lane width, delineation, curvature, grade etc.) which act as an input to iRAP model for generating Star Rating Score (SRS). Star Rating is directly related to risk of accidents. Higher star rating for a road section reduces relative accident risk as compared to lower star rating roads. Also to enhance star rating countermeasures have suggested.Countermeasures which will enhance the deficient road safety aspects are basic requirements for safe road design (e.g. proper delineation, signage, good riding surface, proper design of intersections

Keywords: Road assignment, Vehicular Occupent, Star Rating, iRAP, Traffic Volume, Vehicular Speed

Pages: 50 - 55 | DOI: 10.15224/978-1-63248-096-5-41