Journal of Engineering

A time series analysis can help to observe the behavior of the system and specify the system faults. In addition, it also helps to explain the various energy flows in the system and further aid in reducing the thermodynamic losses. The intelligent supervisory LabVIEW software can monitor the incoming data from the system by using Arduino microcontroller and calculates the important parameters. Energy, exergy, and anergy analysis present in this paper to investigate the system performance as well as its components. To accomplish this, a 4-ton vertical split air conditioner based on vapor compression refrigeration cycle charged with refrigerant R-22 was modified for experimental analysis. The results showed that during 5400 secs of experimental study, the system shut down once by the software for 5 min. The volumetric and isentropic efficiencies of the compressor were 79.85 % and 64.48 % respectively. The maximum entropy generation was due to the compressor of 3.4 W/K while the maximum anergy was due to the condenser of 1.39 kW. The exergy efficiencies of the compressor, condenser, and the evaporator were 73.57, 40.18, and 47.45 % respectively. The system and Carnot COP were 2.53 and 4.9 respectively. The exergy efficiency of the air conditioning system was 48.7 %.

A Geographic Information System (GIS) is a computerized database management system for accumulating, storage, retrieval, analysis, and display spatial data. In general, GIS contains two broad categories of information, geo-referenced spatial data and attribute data. Geo-referenced spatial data define objects that have an orientation and relationship in two or three-dimensional space, while attribute data is qualitative data that can be counted for recording and analysis. The main aim of this research is to reveal the role of GIS technology in the enhancement of bridge maintenance management system components such as the output results, and make it more interpretable through dynamic colour coding and more sophisticated visualization techniques than the conventional tabular data format. To achieve the main objective of this research, two study areas have been chosen: the old construction bridge (Al-Qadisiyah bridge) and the newly constructed bridge (Barboty bridge). Both of them are in Al-Muthanna city \\ Iraq. The data collection process was achieved in two stages: the first stage is providing a georeferenced satellite image for each study area for the purpose of producing a two-dimensional map. The second stage includes the field surveying process by total station and level instruments. GIS have been used to create a comprehensive database (Geodatabase) for both study areas. Geostatistical analysis was carried out in which the settlement areas of both study areas were defined by producing a colour image. The statistical tables for these analyses showed that the highest decline in the elevation reached at Al-Qadisiyah bridge to 19 mm in the middle of the bridge which is coloured as a red area. On the other hand, it was found that the highest decline in the elevation of the Barboty bridge is 16 mm in the last part of steel space which is also coloured as a red area.

A plastic tubes used as absorber of active flat plate solar collector (FPSC) for heating water were studied numerically and experimentally. The set-up is located in Babylon (republic of Iraq) 43.80 East longitude and 32.30 North latitude with titled of 450 toward the south direction. The study involved three dimensions mathematical model for flat coil plastic absorber which solved by FLUENT-ANSYS-R.18 program. Experiments were conducted at outdoor conditions for clear days on January and February 2018 with various water volume flow rates namely (500, 750, 1000, 1250, and 1500 Liter per hour LPH) on each month for Reynolds number range of (1 x 104 to 5 x 104) through the receiver. The experimental results showed improvement in absorber input - output temperature difference, collector efficiency, and water storage temperature; the maximum input - output temperature difference is 3.1 °C, the maximum collector efficiency is 79%, and the maximum water storage temperature is 67 °C. The comparison validates a good agreement between the numerical and experimental results at variable operation conditions with maximum deviation of 4.2%. Also the experimental results were compared with previous study for similar condition and gave a good improvement.

Blades of gas turbine are usually subjected to high thermal cyclic loads, which lead to crack initiation, crack growth, and eventually failure. These high thermal cyclic loads typically arise from high temperature, high pressure, start-up, shut-down, and load changes. An experimental and numerical analysis was conducted on both a real blade and a model blade to simulate the actual conditions in a gas turbine. The pressure, temperature distribution, stress intensity factor, and thermal stress in the model blade were investigated numerically using ANSYS V.17 software. Experimental work was carried out using a specially designed and manufactured rig to simulate the real conditions that the blade experiences. A new controlled method in this rig was proposed for heating the specimen using an oxygen-gas flame. The numerical results showed that the temperature distribution over the blade varied with load changes, leading to an increase in the stress intensity factor along the crack. The experimental results indicated that the rate of crack propagation varied with the position of the crack and the angle of inclination. Based on these results, more effective cracks on the blade were identified, which significantly affect the blade's lifetime.

Numerical study is adapted to combine between piezoelectric fan as a turbulent air flow generator and perforated finned heat sinks. A single piezoelectric fan with different tip amplitudes placed eccentrically at the duct entrance. The problem of solid and perforated finned heat sinks is solved and analyzed numerically by using Ansys 17.2 fluent, and solving three dimensional energy and Navier–Stokes equations that set with RNG based k−ε scalable wall function turbulent model. Finite volume algorithm is used to solve both phases of solid and fluid. Calculations are done for three values of piezoelectric fan amplitudes 25 mm, 30 mm, and 40 mm, respectively. Results of this numerical study are compared with previous both numerical and experimental studies and give a good agreement. Numerical solution is invoked to explain the behavior of air flow and temperature distribution for two types of circular axial and lateral perforations. For each type, all the results are compared with an identical solid finned heat sink. Perforations show a remarkable enhanced in the heat transfer characteristics. The results achieved enhancement in the heat transfer coefficient about 12% in axial perforation and 25% in the lateral perforation at the maximum fan amplitude.

The basic idea of the Main Outfall Drain (MOD) was to construct a main channel to collect saline drained water from irrigation projects within central and southern parts of Iraq and discharge it into the Arabian Gulf. The MOD has navigation lock structures near Addalmage Lake at station 299.4 km. This structure is designed to ensure navigation within the MOD. The water level difference upstream of the cross regulator and the downstream conjugation structure is about 9 meters. This head difference can be used to generate electrical power by constructing a low head power plant. This study aimed to utilize the head difference in navigation lock structures for power generation. Different operation conditions and plant locations were examined. Hydrologic and hydraulic simulations were used to analyze the system of the MOD-Addalmage Lake system. Results showed that the water levels are kept below the dike level along the reaches in all alternatives, and the maximum average annual power generated varies between 3.41 MW to 5.55 MW depending on the selected alternative of operation and the site of the plant.

In this paper, an adaptive integral Sliding Mode Control (SMC) is employed to control the speed of a Three-Phase Induction Motor. The strategy used is the field-oriented control as an AC drive system. The SMC is used to estimate the frequency required to generate three-phase voltage of Space Vector Pulse Width Modulation (SVPWM) inverter. When the SMC is used with a current controller, the quadratic component of stator current is estimated by the controller. Instead of using a current controller, this paper proposed estimating the frequency of stator voltage since the slip speed is a function of the quadratic current. The simulation results of using the SMC showed that a good dynamic response can be obtained under load disturbances as compared with the classical PI controller. The complete mathematical model of the system is described and simulated in MATLAB/SIMULINK.

Affinity is a term used to describe the amount of the adhesion bond between asphalt binder and aggregate. Adhesion force may be used as an indicator of the amount of energy or work required to break down the adhesive bond between asphalt binder and aggregate. In order to study the affinity between asphalt binder and aggregate, a modified device similar to the Rolling Bottle Test (RBT) was manufactured locally to predict the degree of affinity between asphalt binder and aggregate. This study took into consideration the mineral composition and physical properties of the asphalt binder to measure the required force to separate the asphalt binder from the aggregate surface. New parameters were suggested to represent the stripping or affinity phenomena (affinity and stripping ratio) and the time required to balance between them. The experimental results showed that the affinity ratio of aggregate from the Dohuk region was 52% after 24 hours of rolling time, which is less than other types due to its mineral composition (high percentage of calcite and dolomite, which increase the ability to resist stripping), pore size, and stiffness of aggregate particles. On the other hand, the stripping ratio of aggregate from the Al-Taji quarry was 80% after 24 hours of rolling time, representing the worst case in the affinity of the aggregate-asphalt binder system due to the increased percentage of quartz in the mineral composition (greater than 80%), reducing the ability of the aggregate to resist stripping.

The characters of facades' form of the Iraqi building after 2003 have been changed, it has been described by many names. The problem of the research is that what are the features of the characters of the form in the façades of the buildings in Baghdad city after 2003? Are the façade of the individual houses or the commercial buildings is the heaviest in the visual weight? The research aims to answer those questions by choosing the vernacular architecture as a measurement tool. It is the informal image of the architecture, which is built by people informally and spontaneously, without official control and legislation to be organized. This is similar to what has happened in Baghdad, after 2003 according to previous study submitted by the same researcher (The phenomenon of trespassing the architectural design regulation in the Iraqi cities 2003-2016- case study Baghdad) the individual houses as a case study. The research method has dealt with the previous studies, and with the terms and the vernacular architecture in some Arabic countries. The research determines the features of the form's characters in the façades of the vernacular architecture in Egypt, Yemen, and Palestine as the generic features of the vernacular taste in Arabic societies. The researcher examines these features by checking list and Excel program and by selecting samples in Zayoona district after 2003 as a case study. The research's hypothesis has proved that the form's characters of local façades in Baghdad after 2003 are a rural vernacular. The facades of the individual houses have had the heaviest influences at the visual weight. The research has concluded that the characters of the vernacular architecture's form have common and basic styles among societies. when it has manifested in cities, showed their architectural style and identity, it indicates a decline in both architectural style and identity. The heavy influences of the visual weight in Iraqi architecture after 2003 depends on the decoration included two types: the rhythmic and geometric decoration, being important elements in the facades.