The present research includes an experimental study for the effect of fins perforation on
the performance of helically finned tubes. The experiments were made on five models of (18
mm) diameter tubes finned spirally with (12mm) high fins perforated with a circular holes ,
the number of holes was (3-3-6&2 hole /fin) and their diameters were (3,4,2&3mm)
respectively .Each tube was tests horizontally by forcing air with(1.5-7.5 m/s) maximum
velocity and Reynolds number range (
3
105.7 10 3
21.1510
) on the tube .The effect of
number and diameter of holes were studied.The experimental results showed that the fins
perforation increase the overall heat transfer coefficie
In this work, calculation of pressure losses in circulating system for two drilling muds is evaluated in Noor oil field. Two types of drilling muds that were used for drilling section 12 1/4" and 8 3/4" which are Salt saturated mud and Ferro Chrome Lignosulfonate-Chrome Lignite mud. These calculations are based on field data that were gathered from the drilling site of well Noor-15, which are included, rheological data, flow data and specification of drill string. Based on the obtained results, the best rheological model that fit their data is the Herschel-Bulkley model according to correlation coefficient value for their two drilling mud. Also, the difference between the calculated pressure lo
... Show MoreNumerical analysis of the cooling process of hot water discharge from a steam power plant into a river has been carried out in the present study. A mathematical model describing the flow field and temperature distribution induced in the river as a result of the cooling process is made based upon the assumptions of steady state, two-dimensional, turbulent flow, in the horizontal plane. The governing equations are the continuity, the momentum, the (К-ε) turbulence model and the energy equation. A proper initial and boundary condition are specified to be used in the solution of the governing equations. A numerical solution of the governing equations is made by using the control volume approach, with non-staggered grid technique and modifi
... Show MoreScrap metal export is currently one of the few thriving industries in Iraq. Looters and legitimate operators are together effectively demolishing many of the old industrial facilities in order to retrieve the metal contained in buildings, processes and storage equipments and vehicles. The mixing of civilian and military scrapping operations such as that occurring at Ouireej is exacerbating the problem. The situation is particularly difficult for Iraq, given the rapid growth of the scrap industry and the lack of security. In view of the current difficulties, the focus was on practical short to medium term improvements such as controlling access to sites, land use zoning, licensing and export controls. The wholesale reform of the scrap met
... Show MoreRegression analysis models are adopted by using SPSS program to predict the 28-day compressive strength as dependent variable and the accelerated compressive strength as independent variable. Three accelerated curing method was adopted, warm water (35ºC) and autogenous according to ASTM C C684-99 and the British method (55ºC) according to BS1881: Part 112:1983. The experimental concrete mix design was according to ACI 211.1. Twenty eight concrete mixes with slump rang (25-50) mm and (75-100)mm for rounded and crushed coarse aggregate with cement content (585, 512, 455, 410, 372 and 341)Kg/m3.
The experimental results showed that the acc
... Show MoreThe rotor dynamics generally deals with vibration of rotating structures. For designing rotors of a high speeds, basically its important to take into account the rotor dynamics characteristics. The modeling features for rotor and bearings support flexibility are described in this paper, by taking these characteristics of rotor dynamics features into standard Finite Element Approach (FEA) model. Transient and harmonic analysis procedures have been found by ANSYS, the idea has been presented to deal with critical speed calculation. This papers shows how elements BEAM188 and COMBI214 are used to represent the shaft and bearings, the dynamic stiffness and damping coefficients of journal bearings as a matrices have been found
... Show MoreThe constructed building in the urban area is subject to wind characteristics due to the influence of surrounding buildings. The residential complexes currently being built in Iraq represent a case study for the subject of this research. Therefore, the objective of this study is to identify the interference effect because of adjacent buildings effects on the mid-rise building. The speed and pressure of the wind have been numerically simulated as well as wind load has been simulated by using a virtual wind tunnel which is available in Autodesk Robot Structural Analysis, RSA, software. Two identical adjacent buildings have been simulated and many coefficients were included in this study such as the spacing, directionality,
... Show MoreRoof in the Iraqi houses normally flattening by a concrete panel. This concrete panel has poor thermal properties. The usage of materials with low thermal conductivity and high specific heat gives a good improvements to the thermal properties of the concrete panel, thus, the indoor room temperature improves. A Mathcad program based on a mathematical model employing complex Fourier series built for a single room building. The model input data are the ambient temperature, solar radiation, and sol-air temperature, which have been treated as a periodic function of time. While, the room construction is constant due to their materials made of it, except the roof properties are taken as a variable generated practically from the
... Show MoreOver the past few decades, the surveying fieldworks were usually carried out based on classical positioning methods for establishing horizontal and vertical geodetic networks. However, these conventional positioning techniques have many drawbacks such as time-consuming, too costly, and require massive effort. Thus, the Global Navigation Satellite System (GNSS) has been invented to fulfill the quickness, increase the accuracy, and overcome all the difficulties inherent in almost every surveying fieldwork. This research assesses the accuracy of local geodetic networks using different Global Navigation Satellite System (GNSS) techniques, such as Static, Precise Point Positioning, Post Processing Kinematic, Session method, a
... Show MoreReservoir fluids properties are very important in reservoir engineering computations such as material balance calculations, well testing analyses, reserve estimates, and numerical reservoir simulations. Isothermal oil compressibility is required in fluid flow problems, extension of fluid properties from values at the bubble point pressure to higher pressures of interest and in material balance calculations (Ramey, Spivey, and McCain). Isothermal oil compressibility is a measure of the fractional change in volume as pressure is changed at constant temperature (McCain). The most accurate method for determining the Isothermal oil compressibility is a laboratory PVT analysis; however, the evaluation of exploratory wells often require an esti
... Show MoreThe calibration of a low-speed wind tunnel (LSWT) test section had been made in the present work. The tunnel was designed and constructed at the Aerodynamics Lab. in the Mechanical Engineering Department/University of Baghdad. The test section design speed is 70 m/s. Frictional loses and uniformity of the flow inside the test section had been tested and calibrated based on the British standards for flow inside ducts and conduits. Pitot-static tube, boundary layer Pitot tube were the main instruments which were used in the present work to measure the flow characteristics with emphasize on the velocity uniformity and boundary layer growth along the walls of the test section. It is found that the maximum calibrated velocity for empty test s
... Show MoreThe flexural vibration characteristics of rectangular plates with linearly varying thickness is examined. The fourth order differential equation is solved by using Lagrange multiplier method. The thickness of the plate varies linearly along x axis and this variation is taken to be symmetric with respect to the middle surface. Simplicity and quick convergence is the advantage of the method in comparison with other much more laborious numerical metods which require extensive computer facilities A power series is used as an admissible function for the displacement function
procedure is presented to calculate an equivalent diameter for soil grains to be used to calculate the specific surface of the soil. The typical grain size distribution curve is expressed as a normal probability distribution cumulative curve and the frequency corresponding to the equivalent diameter is accordingly found. This frequency is adopted as the percent finer corresponding to the equivalent diameter. A relation is given for the calculation of the specific surface using the equivalent diameter. Grain size distribution curves of many soil samples are collected. A value for the specific surface of each soil is determined summing the surface area of subintervals in the distribution curve. The values of specific surface obtained
... Show MoreFive formulations of fuel-rich propellant consisting hydroxy-terminated poly-butadiene (HTPB) based polymer, ammonium perchlorate (AP) and magnesium (Mg) or aluminum (Al) as additive have been processed and investigated. Theoretical calculations of flame temperature and gas composition were determined by NASA-273 computer code. The sustained ignition/ combustion of such propellant is possible with long duration pyrotechnic igniters. The experimental investigations of the effect of solid particle size range and content on fuel ballistic and mechanical properties have revealed that a considerable enhancement may be obtained with fine particle size and high content percent. High air-to-fuel ratio increases the combustion efficiency in the r
... Show MoreThis study found that one of the constructive, necessary, beneficial, most effective, and cost-effective ways to meet the great challenge of rising energy prices is to develop and improve energy quality and efficiency. The process of improving the quality of energy and its means has been carried out in many buildings and around the world. It was found that the thermal insulation process in buildings and educational facilities has become the primary tool for improving energy efficiency, enabling us to improve and develop the internal thermal environment quality processes recommended for users (student - teacher). An excellent and essential empirical study has been conducted to calculate the fundamental values of the
... Show MoreOne of the most important steps in the world of printed circuit board manufacturing (PCB) is the copper etching process. Because of its low cost, environment aspects, and simple regeneration techniques, cupric chloride was chosen to be the most attractive etchant. Etching of copper from standard single-sided copper boards used usually for printed circuit board fabrication was conducted in a cell containing cupric chloride solution. Average etching rates were recorded as a function of time, etchant specific gravity, free acid concentration, and temperature. Air was injected continuously in the etching cell during the process enabling mixing and solution regeneration. It is found that best operating conditions to obtain maximum etching rat
... Show MoreThis paper presents a fuzzy logic controller for a two-tank level control system, which is a process with a dead time. The fuzzy controller is a proportional-integral (PI-like) fuzzy controller which is suitable for steady state behavior of the system. Transient behavior of the system was improved without the need for a derivative action by suitable change in the rule base of the controller. Simulation results showed the step response of the two-tank level control system when this controller was used to control this plant and the effect of the dead time on the response of the system.
Rhythm is considered one of the creative concepts in the recent architectural thought; it has emerged clearly as a mean of creating the highest levels of creativity in architecture, especially in contemporary architectural movements. The importance of rhythm has emerged, especially, when the architecture , its beginnings concentrated on the principle of the links with poetic structures. Many architectural studies deal with concept of rhythm in architecture with different ways various according to the trend of each study, this show the importance of studying the concept of rhythm in the architectural field in general. This study try to focus on the utilization of rhythm as creative system in architecture of heritage and contemporary
... Show MoreThis paper deals with calculate stresses in Knee-Ankle-Foot-Orthosis as a result of the effect vibration during gait cycle for patient wearing KAFO .Experimental part included measurement interface pressure between KAFO and leg due to action muscles and body weigh on Orthosis. also measurement acceleration result from motion of defected leg by accelerometer .Results of Experimental part used input in theoretical part so as to calculate stresses result from applying pressure and acceleration on KAFO by engineering analysis program ANSYS 14.Resultes show stresses values in upper KAFO greater than lower KAFO that is back to muscles more effective in thigh part lead to recoding pressure higher than pressure in shank part.
In a typical reservoir a sediment layer of considerable depth may be deposited on the top of exposed bedrock foundation. In this research an analytical solution was proposed to solve the case of the vertical acceleration with infinite reservoir with existence of such sediment layer. The results indicate that as the depth of sediment increases, the pressure increases also. The behavior is found to be affected by the change of the degree of saturation of the sediment layer. As this degree of sediment decreases the developed Hydrodynamic pressure increase. A comparison between the case of stiff and soft foundation indicates that the pressure values are always greater for the stiff foundation.
A Vierendeel truss is a hyper static frame composed of a series of rectangular or trapezoidal
panels with out diagonal members. The end conections of all members are rigid and designed to take moment. In this work, the use of fiber reinforced concrete in construction of Vierendeel trusses with nonlinear material behavior is researched. The addition of randomly dispersed discrete steel fibers to concrete improves many engineering properties of the material such as fracture toughness,
fatigue resistance, impact resistance and flexural strength. Several parameters that affected the behavior of the structure like fiber volume fraction, aspect ratio, and the position of the portion in structure that used fibrous concrete are studied.
Ease of transfer between different modes of public transportation within the stations is a significant contribution to the movement that can be provided by transportation industries to develop solutions of integrated transportation. It is future integrated multimodal transportation, to make public transportation more enjoyable and interesting, in addition to passenger transportation and future movement of goods are also depend on multimodal transportation The importance of interchange promotion between multimodal as a basic feature of passengers buildings in modern Railway Stations the Research problem:" con
... Show MoreThe research aims to apply the novel forward osmosis (FO) process to recover pure water
from contaminated water. Phenol was used as organic substance in the feed solution, while sodium
chloride salt was used as draw solution. Membranes used in the FO process is the cellulose
triacetate (CTA) and polyamide (thin film composite (TFC)) membrane. Reverse osmosis process
was used to treatment the draw solution, the exterior from the forward osmosis process. In the FO
process the active layer of the membrane faces the feed solution and the porous support layer faces
the draw solution and this will show the effect of dilutive internal concentration polarization and
concentrative external concentration polarization.
In th
This paper investigates the potential enhancement of the seismic performance of reinforced concrete square columns by modifying their geometry from prismatic to non-prismatic, while maintaining the same volume. Two one-bay by two-bay three-story RC frames were simulated using ABAQUS software; the first has prismatic columns serving as the reference model, and the second has non-prismatic columns. Static lateral loads were applied to both frames after the application of gravity loads. Additionally, two one-bay by one-bay six-story RC buildings were modeled in ABAQUS; one has prismatic columns and the other has non-prismatic columns. These two models were subjected to the El Centro 0.32g NS 1940 earthquake, and time-histor
... Show MoreA numerical finite-volume calculation method was used for application to fully-developed flow and heat transfer in straight ducts with 2-Cusp, 3-Cusp and 4-Cusp cross-sectional area. The method was formulated with reference to a non-orthogonal curvilinear coordinate system which was fitted exactly into duct shape. In turbulent flow, the Reynolds stresses were calculated by using the coupled algebraic stress model of Launder and Ying (1973) with a (k ) transport model. This turbulent stress model enabled secondary flows to be included in the non-circular duct calculations. In heat transfer solution, three thermal boundary conditions were investigated. Predictions were compared with available numerical and experimental data. The turbulent
... Show MoreThe trend towards studying traffic management in software-defined networks (SDN) is increasing widely due to its great importance in enhancing the efficiency of networks and their abilities to adapt to the increasing demands on data and modern applications. What increases the importance of these studies is the integration of artificial intelligence (AI) technologies, which in turn provide intelligent analysis and response capabilities that contribute to improving quality of service (QoS), avoiding congestion, and achieving balanced load distribution across the network. Intelligent management in the SDN controller involves the use of modern algorithms and technologies that have been used previously and have given desirabl
... Show MorePredicting Stream flow forecasting is of great interest to engineers and hydrologists for the management and planning in designing water resources projects and for water resources for. Long-term and short-term stream flow forecasting can provide valuable information on the possibility of designing water projects. This paper aims to improve the hydraulic performance selected channel namely the Shatt al-Ibrahim channel by measuring the depth of flow, using an Inflatable dam and comparing it with the water depth before the dam was placed in operational discharge (2 m3/sec). One-dimensional and two-dimensional numerical models are generated and analyzed using HEC-RSA software and then calibration with a physical m
... Show MoreOne of the advanced techniques in enhanced oil recovery (EOR) is the miscible injection of carbon dioxide (CO2), which can both boost oil displacement and decrease the greenhouse effect. One of the most important indicators for ensuring full miscibility between two phases and optimal injection process efficiency is the Minimum Miscibility Pressure (MMP). There are many methods, such as experimental methods, that are accurate yet costly and time-consuming for determining the MMP; thus, researchers often turn to mathematical techniques, including equations of state and empirical correlations. This study aims to determine the minimum miscible pressure for CO2 in one of the Iraqi fields for its import
... Show MoreThis study examines residents’ perceptions, attachments, and preferences for neighborhood improvements in Sulaimani, Iraq, a city undergoing rapid urban transformation. The research aims to address two key objectives: (1) To investigate how residents perceive and attach to their old and current neighborhoods; (2) To explore what are their priorities for neighborhood improvements. Using the TwoStep Cluster model in IBM SPSS Modeler, residents were grouped based on their satisfaction with their neighborhoods and their priorities for architectural and infrastructure enhancements. The findings indicate a dual focus: while residents appreciate modern amenities, such as energy-efficient designs and improved public spaces, th
... Show MoreThe long-term monitoring of land movements represents the most successful application of the Global Navigation Satellite System (GNSS), particularly the Global Positioning System. However, the application of long term monitoring of land movements depends on the availability of homogenous and consistent daily position time series of stations over a period of time. Such time series can be produced very efficiently by using Precise Point Positioning and Double Difference techniques based on particular sophisticated GNSS processing softwares. Nonetheless, these rely on the availability of GNSS products which are precise satellite orbit and clock, and Earth orientation parameters. Unfortunately, several changes and modifications have been mad
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