Process Simulation and Abrasion Behavior of Jet Electrodeposited Ni–TiN Nanocoatings

In this work, we study jet-electrodeposited Ni–TiN composite nanocoatings (CNCs) for improving abrasion resistance as a function of various nozzle diameters. In addition, COMSOL software is utilized to simulate the process of jet electrodeposition, particularly the influence of spraying speed and pressure of the electrolyte on the abrasion resistance of coatings. Optimization of the nozzle diameter to obtain uniform and high-performance coatings showed that a Φ7 mm nozzle diameter generated the optimum spraying speed and spraying pressure, which results in good micro-hardness and abrasion resistance of the Ni–TiN CNCs. Under these conditions, the 45 steel substrates are coated with a compact layer of uniform and nano-sized TiN particles, which are responsible for the high abrasion resistance of our Ni–TiN CNCs. Our study may motivate researchers to study jet electrodeposition in order to obtain abrasion-resistant coatings.

Simulation study of droplet formation in inkjet printing using ANSYS FLUENT

Flow simulations of jetting of inkjet drops are presented for water and ethylene glycol. In the inkjet printing process, droplet jetting behaviour is the deciding parameter for print quality. The multiphase volume of fluid (VOF) method is used because the interaction between two phases (air and liquid) is involved in the drop formation process. The commercial inkjet printer has a nozzle diameter of ∼73.2μm. In this work, a simulation model of inkjet printer nozzles with different diameters 40μm, 60μm, and 80μm are developed using ANSYS FLUENT software. It is observed that when water is taken as solvent then the stable droplets are generated at 60μm nozzle diameter till 9μs because of its low viscosity. For higher diameter, the stamen formation is observed. Ethylene glycol stable droplets are achieved at 80μm nozzle diameter till 9μs because of their high viscosity (∼10 times that of water). Along with the droplet formation, the sustainability of the droplet in the air before reaching the substrate is also important. The simulation model is an inexpensive, fast, and flexible alternative to study the ink characteristics of the real-world system without wasting resources.

Application of Computational Fluid Dynamics (CFD) in the Deposition Process and Printability Assessment of 3D Printing Using Rice Paste

Computational fluid dynamics (CFD) was utilized to investigate the deposition process and printability of rice paste. The rheological and preliminary printing studies showed that paste formed from rice to water ratio (100:80) is suitable for 3D printing (3DP). Controlling the ambient temperature at C also contributed to improving the printed sample’s structural stability. The viscoelastic simulation indicated that the nozzle diameter influenced the flow properties of the printed material. As the nozzle diameter decreased (1.2 mm to 0.8 mm), the die swell ratio increased (13.7 to 15.15%). The rise in the swell ratio was a result of the increasing pressure gradient at the nozzle exit (5.48 × 106 Pa to 1.53 × 107 Pa). The additive simulation showed that the nozzle diameter affected both the residual stress and overall deformation of the sample. CFD analysis, therefore, demonstrates a significant advantage in optimizing the operating conditions for printing rice paste.

Influence of flow parameters in the dual nozzle CO2-based vortex tube cooling system during turning of Ti-6Al-4V

Dual nozzle vortex tube cooling system (VTCS) is developed to improve the machinability of Ti-6Al-4V where cold-compressed CO2 gas is used as a coolant. The cooling effect is produced by the process of energy separation in the vortex tube and the coolant is supplied into the machining zone to remove the generated heat in machining. In this study, the responses such as cutting force (Fz), cutting temperature (Tm), and surface roughness (Ra) are analyzed by considering coolant inlet pressure, cold fraction, and nozzle diameter as input variables. Further optimization is performed for the input variables using the genetic algorithm technique, and the results at optimum conditions are compared with those of dry cutting. From the results, lower cutting force is observed at lower coolant pressure and cold fraction and higher nozzle diameter. The cutting temperature is minimized by increasing coolant pressure and cold fraction and by decreasing nozzle diameter. A better surface finish is observed at high coolant pressure and cold fraction and lower nozzle diameters. It is observed from the response surface method (RSM) that the coolant pressure is most significantly affecting all the responses. At optimum conditions, the cutting temperature and surface roughness are 35.6% and 66.14%, respectively, lower than dry cutting due to the effective cooling and lubricating action of the CO2 gas, whereas cutting force observed under the VTCS is 18.6% higher than that of dry cutting because of the impulse force of the coolant VTCS and thermal softening of the workpiece in dry cutting.

ANALISIS UNJUK KERJA KOLEKTOR SURYA PELAT DATAR DENGAN PENAMBAHAN SIRIP BERLUBANG BERDIAMETER BEDA SEBAGAI NOSEL YANG DISUSUN SECARA STAGGERED

The solar collector is a device that collects solar radiation and converts it into useful heatenergy. Several types of solar collectors include the parallel flow flat plate solar collector and theperpendicular flow absorber plate solar collector. Previous design of flat plate solar collectorperpendicular flow absorber plate usually uses plates with the same hole diameter. To improve theperformance of this solar collector, modifications have been made by adding perforated fins withdifferent diameters which are arranged staggeredly as an air flow channel or nozzle. The intendedmodification of nozzle diameter is to make the nozzle diameter size different from the large diameter nearthe inlet to the small diameter near the oulet and compared to the reverse nozzle position. Making thediameter of the nozzle near the inlet is larger than the diameter of the hole near the outlet aims to makethe mass flow of air passing through the hole near the inlet larger, so that the flow of air massesexperiences more heat transfer while the diameter of the hole near the outlet is made small is to reducethe mass flow of air which is wasted faster through the outlet channel. With the variation of the holediameter from large to small, it is expected that the heat transfer that occurs in the solar collector will bemore optimal, but it should also be seen in the reverse position. The research was carried outexperimentally. The results of his research show that the useful energy and efficiency of solar collectorswith large to small diameter slotted fins are higher than those with small to large diameter slotted fins.

Modeling of the Influence of Input AM Parameters on Dimensional Error and Form Errors in PLA Parts Printed with FFF Technology

As is widely known, additive manufacturing (AM) allows very complex parts to be manufactured with porous structures at a relatively low cost and in relatively low manufacturing times. However, it is necessary to determine in a precise way the input values that allow better results to be obtained in terms of microgeometry, form errors, and dimensional error. In an earlier work, the influence of the process parameters on surface roughness obtained in fused filament fabrication (FFF) processes was analyzed. This present study focuses on form errors as well as on dimensional error of hemispherical cups, with a similar shape to that of the acetabular cup of hip prostheses. The specimens were 3D printed in polylactic acid (PLA). Process variables are nozzle diameter, temperature, layer height, print speed, and extrusion multiplier. Their influence on roundness, concentricity, and dimensional error is considered. To do this, adaptive neuro-fuzzy inference systems (ANFIS) models were used. It was observed that dimensional error, roundness, and concentricity depend mainly on the nozzle diameter and on layer height. Moreover, high nozzle diameter of 0.6 mm and high layer height of 0.3 mm are not recommended. A desirability function was employed along with the ANFIS models in order to determine the optimal manufacturing conditions. The main aim of the multi-objective optimization study was to minimize average surface roughness (Ra) and roundness, while dimensional error was kept within the interval Dimensional Error≤0.01. When the simultaneous optimization of both the internal and the external surface of the parts is performed, it is recommended that a nozzle diameter of 0.4 mm be used, to have a temperature of 197 °C, a layer height of 0.1 mm, a print speed of 42 mm/s, and extrusion multiplier of 94.8%. This study will help to determine the influence of the process parameters on the quality of the manufactured parts.

Study on Influencing Factors and Laws of Fuel Injection Consistency of Common Rail Injector

In order to study the influence of parameters of common rail injector internal components on cycle injection consistency, its simulation model is established by AMESim, and the model is validated by the experimental injection rate data. The effects of solenoid valve spring preload, gag bit lift, fuel discharge hole diameter, fuel inlet hole diameter, needle valve lift, needle valve preload and nozzle diameter on the change of injection quantity under different operating conditions are studied by simulation method, and the impact weight of each parameter on fuel injection consistency is analyzed. The results show that the preload of solenoid valve, fuel discharge hole diameter, oil inlet hole diameter, needle valve lift and nozzle diameter are the main parameters affecting the consistency of cycle injection. The percentages of five parameters influencing on the consistency of cyclic injection are 8.68-16.84%, 11.41-23.68%, 17.2086-37.74%, 12.772-18.34% and 9.69-37.27% respectively.