Vol. 12 No. 3 (2019)
Articles
Abstract: A lab scale pellet reactor (PR) was designed and fabricated to carry out extensive investigations on the removal efficiency of the hardness of groundwater. The groundwater of 2200 – 2600 mg/L hardness was collected from Abdulla Ibnalhassan wells area located at the west desert of Al-Shinafiyah district (70 km to the southwest of Al-Dewaniyah city, Iraq). Both hydrodynamic parameters of the pellet reactor (porosity and fluidized bed height) and the parameters of calcium carbonate crystallization process (calcium carbonate equilibrium, pellet size, and density) were modeled and compared with the experimental results of the lab scale pellet reactor. The comparison showed that fair agreement between modeled and measured results was observed. The removal efficiency of both calcium and magnesium ions were 62.5-99% and 83-99% respectively. The removal efficiency was found to be strongly dependent on pH and the ratio of NaOH solution flow rate to the groundwater flow rate in the pellet reactor.
Abstract: An electrochemical oxidation method was performed in a batch electrochemical reactor using graphite anodes for treating an effluent obtained from Al-Diwaniyah petroleum refinery plant. The effective f process parameters like current density (4-20m Acm-2), pH (3-9), and NaCl concentration (0-3 g/l) on the COD and phenol removal efficiency have been investigated. The results reveal that the best conditions were current density 12 mA cm-2, pH 7, NaCl concentration 2 gl-1 at a treatment time of 60 minutes. Under best conditions of COD removal efficiency 100% and phenol removal efficiency 99.12% were obtained at current efficiency 33.5% and power consumption 59.9 kWh/kg COD. The anodic oxidation was proven to be efficient for treatment Al-Diwaniyah petroleum refinery effluent to get effluent with features in agreement with the standard limits for discharge to the environment at a lower cost.
Abstract: Numerical investigate of double-diffusive natural convection in an inclined porous square. Two opposing walls of the square cavity are adiabatic; while the other walls are, kept at constant concentrations and temperatures. The Darcy–Forchheimer–Brinkman model is used to solve the governing equations with the Boussinesq approximation. A code written in FORTRAN language developed to solve the governing equations in dimensionless forms using a finite volume approach with a SIMPLER algorithm. The results presented in U-velocity and V-velocity, isotherms, iso-concentration, streamline, the average Nusselt number, and the average Sherwood number for different values of the dimensionless parameters. A wide range of these parameters have been used including; Darcy Number, modified Rayleigh number, Lewis number, buoyancy ratio, and inclination angle. The results show that for opposite buoyancy ratio (N≤-1), the Nu decreases when the Le increases and the Sh increase when the Le increases. For an (N>0), the Nu increases when the Le increases until Le is equal to 1 and then it decreases, also Sh increases when the Le increases
Abstract: Given the importance of gas turbines in the process and amount of global energy from fossil fuels, the views were directed toward this study in addition to the availability of the liquefied petroleum gas and because of knowing many details of it is composition and behavior this type of fuel has been proven. The development of the tangential swirl burner geometry also one of the targets of this study by reducing the combustion instability include flashback and the minimizing in the burner size comparing with other classic tangential swirl burner shape include cylindrical confinement with conical cup confinement. The authors take care in previous studies in field of swirling flow either in scope of geometry characteristics or in scope of fuel issues. The geometrical swirl number which play an important factor in swirling flow had been taken in the consideration for the process of the tangential swirl burner manufacturing as well as the heat caloric value of the operating fuel. The experimental results of combustion the liquefied petroleum gas had been proved that the formal additions added in this study to development the burner nozzle mouth will reduce and improve the occurrence of the operational problems represent flashback and an increasing in the working area by increasing the flashback limits for both premixed and partial premixed combustion modes which will be clarified and the mechanism of composition in the following sections of this paper.
Abstract: In transportation of fluid, the drag reducers in pipeline are important parameters because of drag reduction increased the ability of pump fluid when adding small amounts of additive to fluid. The frictional pressure loss in pipes is waste energy and it very costly so the drag reducing minimizes flow turbulence, reduces the costs of energy and increases throughput. The transportation of reducing crude oil is very difficult and needs some treatment to improve its transportation and this is because of its high viscosity. The purpose of this research is to study the effect of nanoparticles of copper oxide on viscosity of R.C. and other parameters when transport it through pipes. This research investigated the viscosity, pressure drop and other parameters in three pipes (0.0127, 0.01905 and 0.0254 m) I.D. with different concentrations (0.00625, 0.0125, 0.01875, 0.025 and 0.0375 (gm/L) w/v) at 50 oC and the flow rate is 50% of maximum. The results show that the performance of the drag reduction is much better in the larger pipes diameter than the smaller one. Also, the CuO NP's effect on R.C. viscosity and the maximum viscosity deviation is about 4%. In Addition to CuO NP's to R.C. has reduced the %Dr, pressure drop and shear stress.
Abstract: This study was carried out in order to explore the behaviour of RC deep beams strengthening with CFRP strips. Eight simply supported deep beams were fabricated and tested under four-points loading scenario. Three different orientations for CFRP strips were used for strengthening the RC deep beams ; vertical, horizontal and inclined. All of the tested samples were of the same dimensions, concrete strength and steel reinforcement. A percentage increase in load carrying capacity of 48, 19 and 38% (with respect to the unstrengthened beam) was gained for beams strengthened with vertical, horizontal and inclined FRP strips, respectively. It was concluded that the strengthening with FRP strips of vertical fabric orientation is more efficient than strengthening with horizontal or inclined orientation since the vertical orientation gives the highest load carrying capacity, largest deflections at ultimate load and smallest crack width. On the other hand, applied the FRP strips in a horizontal orientation was insufficient for the strengthening purposes.
Abstract: Nowadays, the deep beams become utilized more in a considerable number of structures. It is necessary sometimes to introduce a hole within the web of the beam as a pipe or a duct for many purposes such as water supply, sewage, electricity, air conditioning, and computer network. In this study, a deep beam sample taken from a past experimental study is numerically analysed using a three-dimensional finite element model. ABAQUS tools are used to simulate the whole FE models. The dimensions of the considered deep beam are 820x400x180 mm, with two openings of a diameter 90 mm located at 200 mm from both of the ends. The proposed model and the experimental work have reasonably agreed with a difference of 2 % in mid-span deflection. Furthermore, special reinforcements of 12 mm bar diameter are offered to the original FE model around the holes in two types, Z-shape and circular, to improve the structural behaviour of the deep beam and to minimize the crack concentrations in these zones. The gained results show that the additional reinforcement minimizes the mid-span deflection of the deep beam. As compared with the original proposed FE model, the Z-shape decreases the deflection by 44.9 % while the lowering in the defection of the circular shape is 9.4 %. Moreover, the concentration of stresses and cracks that gained from using the Z-shape reinforcement model found to be lower than those induced in the circular reinforcement model.
Abstract: The aim of the present study is to analyse the combustion characteristics, performance and emission parameters of a variable compression ratio (VCR) diesel engine experimentally and numerically using soybean methyl ester (SME) biodiesel. Initially the engine is fed with diesel to capture the basic data, and then SME was tested as 20 % blend (B20), as 40% blend (B40) and as pure bio-fuel (B100). The experimental investigations are followed by a computational combustion and emissions analysis of diesel engine which is done by using the CFD software (ANSYS FLUENT 13). The combustion, performance and emissions parameters are evaluated by operating the engine at four different compression ratios of 15, 16, 17.5 and 19 and varying the load from 0 kW to 4.4 kW with 1.1 kW step. It is observed that peak pressure is closer to TDC when SME blends is increased. SME blend has earlier combustion start because of the advancement in the injection timing, shorter delay time. Increasing mixing ratio of biodiesel is found to decrease BTE slightly and increases the BSFC. Remarkable decrease in UHC and CO emissions as the ratio of SME is increased due to the complete combustion of biodiesel with presence of more oxygen in the combustion chamber. The measured BSN for B20, B40, and B100 SME was less than that of diesel fuel by 20.44%, 35.78%, and 48.3% respectively. It is inferred from the combustion analysis that as the compression ratio increases from 15 to 19 a decrease in smoke intensity, UHC, and CO, but it increases the emission of NOx. Both turbulent kinetic energy and turbulent dissipation rate were decreased as the percentage of SME increased by 10.84% and 2.01% respectively. The increase in compression ratio from 15 to 19 caused an increase in the peak pressure, density, combustion velocity, turbulence, peak temperature, NOx and a decrease in soot emissions. It can be assessed that the B20 SME is best suited to implement it into diesel engine without any effects. It has been founded from the results that 19 compression ratio has shown good performance and low emissions as compared to other compression ratios. The results obtained from the experimental investigation have been compared with the results of CFD analysis and are found to be in good agreement with each other with just slight deviation.
Abstract: In this paper, an experimental work was conducted to investigate the possibility of improving the structural performance of reinforced self-compacting concrete (SCC) beams cast with 100% treated and untreated recycled aggregate (RA). RA was first exposed to a simple treatment method to reduce the amount of its adhered mortar and to improve its performance by the impregnation in polyvinyl alcohol (PVA) polymer solution. After completing RA treatments, rectangular simply supported reinforced SCC beams cast with RA, treated recycled aggregate (TRA) as well as normal aggregate (NA), were prepared and tested under two-point loading up to failure. Half of the prepared beams were tested to evaluate the shear behaviour of normal strength (NS) SCC mixes, while the other half was tested for high strength (HS) SCC mixes. The results were evaluated with regards to load deflection response, ultimate failure load, first crack load, and cracking pattern. The main experimental results demonstrated that using treated RA considerably improved the shear capacity of reinforced SCC beams in comparison with that of untreated RA. Based on the ACI 318-14 and Euro codes, the shear strength values showed that the treated RA beams were considered more conservative compared to the RA beams in both strength grades.