University of Thi-Qar Journal for Engineering Sciences

Two-phase local heat transfer coefficient and flow pattern in 4.5 cm inner length of glass square test section downwardly pipe inclination angles of 5o, 10o, and 15o were investigated experimentally. Two superficial velocities for each air and water were used 0.164 m/s, 0.411 m/s and 1.1506 m/s, 1.4815m/s respectively. Local heat transfer coefficient was calculated from the temperature recorded by using eight thermocouples type K positioned along the test section. It was found that the heat transfer coefficient of air-water flow increase with increasing flow rate of water, air, and inclination angle. In addition a high speed camera was used in order to obtain images sequence of the flow under different selected conditions. The flow regimes, which are stratified, intermittent, and annular flow are observed and recorded by high speed camera. At 5o inclination angle and low air-water superficial velocity stratified flow observed, transition from stratified to intermittent flow and annular flow occurs at increasing the inclination angle and air-water superficial velocity. Correlations on average Nusselt number were obtained for three inclination angle 5o, 10o, and 15o.

The proper condition of the emulsion liquid membrane (ELM) technique for the recovery and concentration of copper (II) from model water is investigated. The ELM is a solution of di (2-ethylhexyl) phosphoric acid in kerosene and sorbitan monooleate Span 80 as surfactant. The extraction efficiency of the metallic ion in the ELM in batch tests is determined. The results show good extraction percentage in relatively period of time (15 minutes) under the following conditions: pH of the feed is 8; feed concentration of 500 ppm, carrier concentration of di (2-ethyl-hexyl) phosphoric acid (D2EHPA) 4% and treatment ratio (volume of external phase to volume of emulsion phase) of 2.

Experimental and numerical investigation of a high speed centrifugal pump has been carried out. In experimental work, a test rig which includes a centrifugal pump, fast response piezoelectric pressure transducers, Rota meter flow and measurement instrumentations is designed and constructed. Two impellers having different outlet diameters were examined for the same volute. A data acquisition system (hardware) and its software (Visual Basic language) have been developed to analyze the pressure transducer signal in order to obtain the pressure fluctuations. The governing partial differential equations (continuity, momentum) besides to turbulence model are discretized to algebraic equations by using finite volume method. The solution of these equations was done by using FLUENT 6.3 commercial code. This code has the ability to use a grid generation technique and transform the physical domain to a computational domain by using GAMBIT 2.2.3 software. The effect of turbulence was simulated by using a standard k-e model. The wall function laws are used to remedy the regions near the rotating and volute walls. The effect of angular position of impeller and impeller’s diameter on the flow behavior is studied for different values of volume flow rate. The obtained results show that the pressure fluctuations registered in the volute were found to be very dependent on both angular position and volume flow rate. It is observed that the pressure fluctuations have maximum values at volume flow rate (Q=0.5QN) for the considered two impellers at angular position (?= 270o). These values increase as impeller diameter increases. The results also show that the higher static pressure values are observed upstream of the leading edge at the volute tongue (stagnation point) while the minimum was found at impellers eye. A comparison between experimental and numerical results is done and the agreement was acceptable.

Some types of viscosity for polycarbonate aqueous solution in Chloroform with concentration of 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5% were determined for two kinds of samples, first non-radiated & the second, irradiated with source for a rate of 508 rad/min for 20 minutes. The results show that the values of shear, relative, specific & reduced viscosity were increased with increasing the concentration of polycarbonate in chloroform, Also the properties which had been determined in this work, increased after radiation, this could be attributed to penetration of ionizing radiation in the polymer structure & cross linking the chains.

This work uses the Artificial Neural Networks (ANNs) for fault diagnosis of a single cylinder four stroke gasoline generator type (Astra Korea AST11700). One normal and fourteen faulty conditions are examined experimentally to produce a realistic data set, which is to be used for the training and validation of the ANNs. The resulted data was in the form of exhaust gases and engine speed records for each case separately under different loading conditions. After the learning process is completed, the ANN becomes able to make a diagnosis about the gasoline engine condition when new data is presented. The data presented to the ANN system include a subset of engine faults which were selected and executed experimentally for this topic. These include, faults in carburetor, air filter, spark plug, valves, piston rings, etc. The results showed that the multi layer training algorithm is sufficient enough in diagnose engine faults under different loading conditions. It was found that the correlation coefficient values are 0.999 and 1 for the testing and training data, respectively. The results obtained in this investigation showed that the ANN-based fault diagnosis system is capable of fault diagnosis with high reliability.

This paper is addressed to investigate the possibility of using a waste heat to drive absorption refrigeration system as an alternative system for automobile air conditioning. LiBr-water absorption refrigerator is suggested for this application. A theoretical analysis of the system has been carried out to maximize its cooling potential. This study includes also an actual experimental test to measure the available waste heat that is rejected from water cooling system of a 6-cylinder petrol engine fitted to Toyota Land Cruiser vehicle. The test was performed directly on the vehicle using out-city high way roads. It is found that the wasted energy from the engine cooling system is ranged between 10 kW for idling engine speed and 68 kW when loading. The engine cooling water temperature is ranged between 71 and 84 . The reject heat available in the cooling water system is measured and found to be adequate for producing cooling up to 34 kW, but the low level of the water temperature did not allow the refrigeration system to produce continuous cooling corresponding to engine and vehicle speeds at a refrigeration temperature of 5 to 10 , especially at hot weather condition

The aim of this work is to study the effect of changing welding current on the mechanical and metallurgical properties and choose the best welding current depend on result of study. The present work is an experimental study on effect of changing welding current on properties of seam welding joint for low carbon steel AISI 1005. Experiments results shows with increase welding current, hardness number will increase, also differentness in hardness number between weld nugget and HAZ (Heat Affected Zone) will increase and border of HAZ become bigger. Best mechanical results was achieved when welding current increased this doesn't mean that the highest current will become the suitable one, because the higher current will cause burin through in metal sheets and will cause leakage in products (liquid or gas storage tank), also will effect on grain size and microstructure due to changes in cooling rate, also the final shape of joints its important because most application of this type of weld is weight-goods industries (for civil using), so when use high welding current the final shape of joint will deform. Depended on above the best welding current rang is between 17 ? I < 19 K Amp.

This research present a multiply connected neural network designed to estimate the fractal dimension (Df) using the Random Iteration Algorithm (IFSP). Fractal analysis is a powerful shape recognition tool and has been applied to many pattern recognition problems. Additionally, the one of the most adaptive Random Iteration Algorithm (IFSP) methods for estimating (Df). The architecture presented separates the calculation of (Df) into two sections, a data sampling section and a linear regression section. The data sampling section provides the ability to dyadic ally sample the data. The linear regression section simply calculates the slope of the best line through the sampling results. Instructional program was designed and built according to Knirk and Gustafson Design model, as one of the instructional design model in order to comprehension of the integrated ideas and concepts related to research .

The axial heat conduction in parallel flow microchannel heat exchanger with rectangular ducts was numerically investigated, for laminar, 3-D, incompressible, and steady state flow of water. The governing equations, continuity, Navier-Stokes equations (momentum equations), and the energy equations for the hot and cold fluids were solved by using SIMPLE algorithm with finite volume method and FORTRAN code to obtain the temperature distribution for the two fluids and the separating wall between them. The results play an important role of the axial heat conduction on the effectiveness in parallel flow microchannel heat exchanger and the factors affecting the axial heat conduction are; Reynolds number Re, thermal conductivity ratio , aspect ratio ? and channel volume. Increasing of Re, , ? and channel volume each separately leads to increase the axial heat conduction and vice versa