11 Articles Published

1. DESIGN OF COMPOSITE PIPES WITH DIFFERENT FIBER ORIENTATIONS EVALUATION OF THE INTERNAL PRESSURE CAPACITY

Authors: NOEL O DOWD , TAMER A. SEBAEY

Abstract: Fiber reinforced composites pipes provide excellent strength and stiffness characteristics and high corrosion and erosion resistance. In addition,the possibility to tailor the strength and stiffness characteristics by optimizing the winding angle gives the designer extra flexibility to design different pipe based on the different working conditions.In the current work, GFRP pipe designed with four different winding angles have been tested under internal pressure. Four pipes were manufactured by filament winding with winding angles of ±45/ ±45/ ±45], ±55/ ±55/ ±55], ±63/ ±63/ ±63], and ±63/ ±45/ ±55]. Each pipe has internal diameter of 110 mm, wall-thickness of 3.8 mm, and length of 450 mm. The pipes were exposed to internal pressure to determine their capacities. Under internal pressure, the maximum failure pressure recorded (60 bar) was that for the pipes with ±55]3 winding angles. All specimens failed in the same way of initial leakage, governed by matrix cracking, which

Keywords: Composite, Pipe, Winding angle, Internal pressure

Pages: 1 - 5 | DOI: 10.15224/978-1-63248-163-4-13

2. INTERRELATION OF STRUCTURAL AND KINEMATIC CHARACTERISTICS DURING FREE-SURFACE GRAVITY FLOWS OF GRANULAR MATERIALS

Authors: ANDREY N. KUDI , MAXIM A. TUEV , OLEG O IVANOV , VIKTOR N. DOLGUNIN

Abstract: The interrelationship of flow parameters during free surface gravity flow of cohesionless nonelastic particles is investigated on the basis of a granular medium state equation. The equation establishes the relationship between dilatation, normal pressure and granular temperature. The granular temperature is defined as the sum of three elementary types of kinetic energy of particles in the course of its mutual displacements: relative shear movement, chaotic fluctuation and transversal mass transfer. The investigation was carried out by means of the earlier developed experimental and analytical method presupposing the distribution analysis of particles, falling from the discharge threshold of a rough chute.The profiles of velocity and fraction of the void volume have been determined in rapid gravity flows of modeling materials at simultaneous identification of the interrelationship coefficient of the granular medium state equation.The granular materials consisting of uniform spherical pa

Keywords: granular material; rapid gravity flow; rough chute; state equation; dilatation; granular temperature

Pages: 6 - 12 | DOI: 10.15224/978-1-63248-163-4-14

3. SIMULATING PRECIPITATION AND TEMPERATURE TRENDS IN PAKISTAN USING THREE GCMS UNDER RCP8.5 SCENARIO

Authors: ISHTIAQ HASSAN

Abstract: Precipitation and temperature are the two main factors considered in studies related to climate change and impact of global warming. Such studies involve application of results of climate models. US geological survey developed a web site [1] which provides visualization and access to global and regional (downscaled) climate data. In this study, results of three GCMs i.e. bcc-csm1-1m, HadGEM2-ES and GFDL-CM3, each with RCP8.5 scenarios,have been applied to study changes in precipitation and temperature over Pakistan. The results of three models showed that temperature variation is expected to range from 1.5-2.35 oC during 2025-2049, 3.23-4.48 oC during 2050-2074, and 4.49-6.57 oC during 2071-2095.Taking the average of the three models, this change is 1.89oC, 3.82oC and 5.49oC for the simulated periods of 2025-250, 2050-2074 and 2071-2095, respectively, with reference to modelled values for the base period (1980-2004).The precipitation variation is expected to be 3.31%, 8.16% and 9.45% w

Keywords: Climate, precipitation, temperature, GCM, RCP8.5

Pages: 13 - 17 | DOI: 10.15224/978-1-63248-163-4-15

4. FLUTTER CHARACTERSTICS OF A FLEXIBLE FILAMENT AND ITS CONTROL

Authors: ASHWINI N.AREKAR , DHIRAJ KUMAR , KAMAL PODDAR

Abstract: Flow induced flutter of a thin flexible filament attached to the trailing-edge of a NACA 0015 airfoil was studied experimentally in a low-speed wind tunnel. Hotwire and PIV measurements were carried out to study the nature of the flow field around the airfoil and the filament at different wind speeds. At a critical wind speed,the filament starts to flutter and achieves a mode of limit cycle oscillation (LCO).Beyond the critical wind speed, the flutter frequency of the filament increases with the increase in wind speed. Also, a change in flutter mode, from 2nd to 3rd mode LCO,was observed at a higher wind speed. A trip wire was introduced to the fore-body to control the flutter characteristics of the filament by modifying the boundary layer characteristics. Trip wire was attached to the airfoil surface (one or both sides ofthe airfoil) at different chord-wise locations. A delay in the mode shape transition from 2nd mode to 3rd mode LCO was observed due to the presence of the trip wire a

Keywords: Flexible filament; Flow-induced flutter, Limit cycle oscillation; Flow control

Pages: 18 - 23 | DOI: 10.15224/978-1-63248-163-4-16

5. NONLINEAR RESPONSE OF MEDIUM SIZE CONTINUOUS BRIDGES WITH LRB

Authors: BERTHA OLMOS , JOSE MANUEL JARA

Abstract: The main objectives of this work were to investigate the effects of the nonlinear behavior of the isolation pads on the seismic response of bridges with rubber bearings, and to identify when base isolation improved their seismic performance. To achieve these objectives a parametric study was conducted designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights.The seismic responses (accelerations, displacements and pier seismic forces) were evaluated for three different structural models. The first represented bridges without base isolation; the second corresponded to the same bridges including now rubber bearings with linear elastic behavior that shifted the natural period of the bridge by a factor of 2 to 4. In the third model the seismic response of the base isolated bridges was studied accounting for the nonlinear behavior of the pads. The results show clearly the importance of the nonlinear behavior on the seismic perfo

Keywords: LRB, Brisges, Time history analyses, Nonlinear seismic response, Bridges on hard soil, Bridges on medium stiffness soils.

Pages: 24 - 29 | DOI: 10.15224/978-1-63248-163-4-17

6. NATURAL CONVECTION HEAT TRANSFER IN A SQUARE CAVITY HEATED BY TRAPEZOIDAL BODY USING TWO-PHASE NANOFLUID MODEL

Authors: ALI J. CHAMKHA , AMMAR I. ALSABERY , ISHAK HASHIM

Abstract: Steady laminar natural convection and heat transfer of nanofluid-filled square cavity heated by trapezoidal solid body is studied numerically using the finite element method. The heat source into the cavity is considered by the bottom wall of the trapezoidal body, where this segment is kept at a higher isothermal temperature. The left and right horizontal walls are maintained isothermally with cold temperature while the left and right horizontal walls is thermally insulated. The boundaries of the domain are assumed to be impermeable, the fluid within the cavity is a water-based nanofluid having Al2O3 nanoparticles. The numerical computations are obtained for various parameters of Rayleigh number, nanoparticle volume fraction and thermal conductivity of the trapezoidal body.The heat transfer rate is clearly enhanced with the increasing of the nanoparticle volume fraction and Rayleigh number. However, this enhancement tends to be quite obvious at the interface wall.

Keywords: heat transfer, square cavity, solid trapezoidal body, Thermophoresis, Brownian, two-phase nanofluid model

Pages: 40 - 44 | DOI: 10.15224/978-1-63248-163-4-19

7. INFLUENCE OF BLAST-INDUCED GROUND VIBRATIONS ON BURIED TRANSMISSION PIPELINES

Authors: MARIO DOBRILOVIC , SINISA STANKOVIC , VINKO SKRLEC

Abstract: Drill and blast method is still most economical and efficient practice for different types of excavation. However, in vicinity of buried transmission pipelines, the vibrations must be held below recommended values. Influence of blast induced ground vibrations on buried pipelines has been described throughout three different projects. During the first project, oil pipeline has been partially open allowing extensive measurements directly on it.In this paper, only vibration monitoring data were analyzed and correlation equation between ground vibration and vibration on pipeline has been developed.Such equation is than used to predict vibration on the pipeline where direct measurements were not possible.

Keywords: blast-induced vibrations, charge weight per delay, transmission pipelines

Pages: 45 - 48 | DOI: 10.15224/978-1-63248-163-4-20

8. EXPERIMENTAL TEST RESULTS OF A FABRIC BASED INFRARED HEATING SYSTEM ON A PUBLIC TRANSPORT VEHICLE

Authors: HAYRI EREN , MUSTAFA EROL , VOLKAN KIRMACI

Abstract: From past up to today motor vehicles use engine waste heat in order to warmup passenger compartment and to provide thermal comfort for the passengers.However,waste heat from the engine is sometimes not enough to provide required heat to the vehicle heating system especially in cold countries. In such cases, fuel burner heaters are very often preferred and used. When the coolant temperature is too low, then its temperature increased by burning fuel on the fuel burner heater and heated coolant is then pump to heat exchangers, located inside the passenger compartment, so that heating comfort is achieved. However, this proses both consumes extra fuel as well as increases exhaust emissions left to the atmosphere. On the other hand, when full electric vehicles are considered, which are increasing their shares in the market at every other day, because there is no internal combustion engine, there is no main heat source also. Hence, required heat has to be provided form the vehicle main batter

Keywords: Fabric heating, public transport vehicle heating, innovative heating, novel heating, vehicle electrical heating,

Pages: 49 - 51 | DOI: 10.15224/978-1-63248-163-4-21

9. EFFECT OF DUST ACCUMULATION AND CLEANING PROCESS ON SOLAR REFLECTIVITY OF SOME BUILDING MATERIALS

Authors: AMRE DEIF

Abstract: In countries that are suffering from hot weather, a considerable part of energy is dedicated for cooling the buildings due to the absorbed part of the incident short-wave which results in an increase of the surface temperature of the roof.To overcome this problem, a bright (white) surface can be used to reflect the solar radiation.On the other hand, the Photovoltaic (PV) panels are widely used to convert the sun light into electricity. However, the dust accumulation either on the reflective materials or on the PV panels will cause a substantial reduction on their performance. The present work is a dual-utility because it studies both the effect of dust deposition on the reflectivity of some surfaces and as well the effect of the cleaning process.

Keywords: dust, accumelation, reflectivity, cleaning process, PV, energy savings.

Pages: 52 - 57 | DOI: 10.15224/978-1-63248-163-4-22

10. OSCILLATORY ELECTROOSMOTIC FLOW IN A MICROCHANNEL WITH SLIPPAGE AT THE WALLS

Authors: J. ARCOS , M. PERALTA , O. BAUTISTA

Abstract: In this work, we conduct a theoretical analysis of an oscillatory electroosmotic flow in a parallel-plate microchannel taking into account slippage at the microchannel walls. The governing equations given by the Poisson-Boltzmann (with the Debye Huckel approximation) and momentum equations are nondimensionalized from which four dimensionless parameters appear:an Reynolds angular number, the ratio between the zeta potentials of the microchannel walls, the electrokinetic parameter and the dimensionless slip length which measures the competition between the Navier slip length and the half height microchannel.The principal results indicate that the slippage has a strong influence on the magnitude of the oscillatory electroosmotic flow increasing the velocity magnitude up to 50% for the numerical values used in this work.

Keywords: electroosmotic flow, slippage, microchannel

Pages: 58 - 61 | DOI: 10.15224/978-1-63248-163-4-23

11. COMPARISON OF PRESSURE DROP IN HORIZONTAL WELLBORE FOR 90 DEGREE AND 180 DEGREE PERFORATION PHASING

Authors: MOHAMMED A. ABDULWAHID , QAIS ABDULHASSAN , ZAHRAA M.RASHAD

Abstract: In this paper, numerical study was conducted on perforated pipes with phasing angle 180 degree and 90 degree respectively. The calculation were carried out with ANSYS FLUENT 15.01 using k-E (RNG) model. It concluded from results there is no change in acceleration and frictional wall pressure between 180 degree and 90 degree perforation phasing. Total pressure drop in 90 degree perforation phasing has the highest value compared with 180 phasing angles due to intensified influence of mixing pressure drop. The decreases in additional pressure drop in 90 degree phasing has the lower value in compared to additional pressure drop at 180 degree phasing this is due to intensified influence of mixing effects pressure drop.

Keywords: Horizontal well, perforation, perforation phasing, total pressure drop, additional pressure drop

Pages: 62 - 67 | DOI: 10.15224/978-1-63248-163-4-36