Current Issue : January-March Volume : 2023 Issue Number : 1 Articles : 5 Articles
Internal combustion engines with application in automobiles and other relevant industries constitute significant environmental pollution via the release of toxic exhaust gasses like carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), and nitrogen oxide (NOx). Engine researchers and manufacturers are challenged to develop external and internal measures to ensure environmentally friendly solutions to accommodate and conform to the growing list of emission standards. Therefore, this work presents an experimental investigation of the NOx emission profile of a diesel engine that is fuelled and fitted with waste frying oil-based biodiesel and catalytic converter. Using a single-cylinder, four-stroke air-cooled CI engine at a constant speed of 1900 rpm and different loadings of 25%, 50%, 75%, and 100%; fitted with a catalytic converter at the exhaust outlet of the engine and linked to a dynamometer and a gas analyser, an experiment was conducted at biodiesel/diesel volume blends of B0 (0/10), B5 (5/95), B20 (20/80), B30 (30/70), B70 (70/30), B100 (100/0); and 30% concentration (v/v), 0.5 litre/hr flow rate of aqueous urea from the catalytic converter. The results show an increasing NOx emission as the biodiesel component increased in the blend. The catalytic converter showed a downward NOx reduction with a significant 68% reduction in efficiency at high exhaust gas temperatures. It is concluded that the combined utilisation of waste frying oil-based biodiesel and the catalytic converter yields substantial NOx emission reduction....
Welding joint is a key component in steel structure engineering, which is often subjected to complex stress and becomes the weak link of building structure, and different fracture modes may appear under different stress. In this study, the ductile fracture of Q345 steel welded joint was investigated by selecting the base material and heat-affected zone (HAZ) material. Based on the J–C (Johnson–Cook) fracture model of stress triaxiality factor, a series of round bar specimens were designed for the tensile test, and the variation of minimum diameter and gauge distance was tracked in real time by digital image correlation (DIC) technology, and the cloud map of strain distribution in the whole loading process was obtained. The constitutive model and fracture criterion model of Q345 steel welded joint base material and HAZmaterial are established through experimental measurement.Theresults show that the maximum triaxial stress is at the center root of the minimum diameter of the notched round bar tensile specimen, the sudden change of the notched edge will lead to stress concentration, the stress change of the notch section is the most significant, extending from near the notch, the maximum strain is at the root of the notch, and the fracture position appears at the minimum section of the notch. According to the true stress-strain curve of a standard tensile specimen and the least square method, the values of parameters A, B, and N of the J–C (Johnson–Cook) constitutive model of base material and HAZmaterial are 379.80, 452.89, and 0.37 and 392.90, 540.61, and 0.49, respectively.Thefracture strains of the base metal and HAZ material under different triaxial stresses were measured experimentally, and the J–C fracture model was fitted. The values of failure criterion parameters D1, D2, and D 3 were 1.025, −0.008, and 3.617 and 0.678, −2.689E-5, and 7.683, respectively. This provides experimental parameters for mechanical properties and fracture models of welded joints in structural engineering, refined finite element models considering material failure for structural numerical analysis, and basic data for evaluation and design of building structures, which have good social and economic benefits....
In the design of the CAT 3408 engine, the Low Temperature (BT) circuits used to cool the engine lubricating oil and the charge air and the High Temperature (HT) circuits for cooling the cylinder liners, cylinder heads and body of turbofans are mainly used to cool the engine, so that it works properly. This work, based on the analysis carried out, to determine the lubrication compliance of the Yacco VX 100 - SAE 15 W-40 oil and that of the Camwater water used in the engine of the Boat Yang 1 by carrying out a series of conventional tests such as that: the density, the viscosity, the viscosity index, the flash point, the density, the sulphate center content, the water content, the total acidity index (TAN), total basic number (TBN) and pour point for the oil case and pH, hardness, sodium chloride content [NaCl], sodium sulphate content [NaSO4] for the water case which will be compared to the specified requirements to determine whether compliance is achieved for each of these characteristics. The results of the oil and water samples taken from the engine after use show that the used oil gives a specific gravity of 0.8822, a viscosity (at 40˚C) of 92.29 mm2/s, a viscosity (at 100˚C) of 13.99 mm2/s, a viscosity index (VI) of 155.39, a pour point −21˚C, a Flash Point (VO) 215˚C, a Sulfated ash content of 18%, a density 881.5 kg/m3, a total basic number (TBN) of 12.60 mgKOH/g, a Total Acid Index (TAN) of 3.096 mgKOH/g, a Water Content of 1.8 % and the water used gives a pH of 6.00, a hardness of 3.2 french degrees, a sodium chloride content [NaCl] of 0.468 mg/L, and a calcium sulphate content [CaSO4] of 2.38345 mg/L. the results of the water content and content of sulfated centers justify the thermal overload and power losses in the marine diesel engine CAT 3408 of the boat Yang 1 because of their values which are not in conformity with the standards....
The utilization of nanoparticle in ethanol-diesel emulsions combustion catalyst is important. For this study, ethanol and diesel fuels are emulsified varying the ethanol amount as 5, 10, and 15% volume ratio designated as E5, E10, and E15, respectively, by using span 80 and tween 80 emulsifying agents. Nickel Zinc Iron Oxide (NiZnFe2O4) nanoparticle is used in each fuel sample with a dose rate of 25, 50, and 100 ppm. Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant is used to keep the nanoparticle homogeneously suspended in the fuel. Mechanical steering and ultrasonic vibrator are used to prepare the sample fuel. A singlecylinder diesel engine testing rig is used to test the performance. For the ethanol-diesel emulsion, the power and torque output decreased as the ethanol percentage and the BSFC increased. The nanoparticle addition improved power and torque output and reduced BSFC. Ethanol-diesel emulsion fuel performance characteristics could be improved with the utilization of NiZnFe2O4....
High-density polyethylene (HDPE) pipes are the preferred pipes of water systems in nuclear power plants because they are durable, corrosion-free, easy to install, and not subject to fouling. However, their long-term performance can be affected by welding defects. In this paper, the effect of welding defects on the long-term performance of HDPE pipe butt fusion joints was studied using a creep test. A welding defect with a hole or inclusion in the joint was simulated by artificially inserting a copper ball during butt fusion welding. The test results showed that the creep life of the joint decreased with increased defect size. An expression describing the creep life and the defect ratio was obtained according to the test results. In addition, the test results showed that the creep life of the joint without a welding bead was about 50% of that in a joint with a welding bead....
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