Papers by Keyword: Velocity

Abstract: The resistance created by vegetation against flow in open channels should be taken into account in projects focused on watercourse management and river restoration. Staggered patches of vegetation in an open channel significantly influence flow structure and river geomorphology. This study numerically examines flow characteristics through longitudinal discontinuous vegetation patches using three-dimensional software FLUENT, with a Reynolds stress turbulent model applied. ANSYS FLUENT Computational Fluid Dynamics techniques were utilized to analyze variations in mean stream velocity within the model domain. This study presents different distributions and profiles of mean stream velocities. It was observed that velocity decreases in the vegetation zones due to resistance. To monitor their effects on flow velocity, experimental vegetation patches should be installed along riverbanks, wetlands, or in stormwater channels.

Abstract: Monosodium Glutamate (MSG) [1] was invented more than 100 years ago from its first invention in 1908 by Japanese biochemist Kikunae Ikeda, who was trying to isolate and duplicate the savory taste of kombu, an edible seaweed used as a base for many Japanese soups. From 2016, most MSG worldwide is produced by bacterial fermentation in a process similar to making vinegar or yogurt. Sodium is added later, for neutralization. During fermentation, Corynebacterium species, cultured with ammonia and carbohydrates from sugar beets, sugarcane, tapioca (cassava tuber) or molasses, excrete amino acids into a culture broth from which L-glutamate is isolated. In this process, Monosodium Glutamate companies buy cassava [2] pulps from farmers that contain a lot of sand and impurities. In order to increase the productivity with lowest expense, the filtration of sand and solid impurities’ is performed by separation cyclone. In this paper, we study all the measure to design a system of effective pump, cyclone to extract as much as possible all of solid impurities included sand out of cassava slurry before providing to the bacterial fermentation in a process.

Abstract: This paper presents the simulation of beef freezing process by using ANSYS software. On the basis of simulation results, factors affecting the freezing time including air velocity and freezing temperature were determined. Within the air velocity range ω = (5÷15) m.s^-1, an increase in the velocity by ω=1 m.s^-1 led to a decrease in the freezing time by τ =(6,5÷2,0) %. When the freezing temperature was reduced by t_e = 1 K, the freezing time was reduced by τ = (3,2÷2,5) % in the freezing temperature range t_e = (–35÷–45) °C.

Abstract: The paper is devoted to the study of the influence of factors on the rate of return deformation of polytetrafluoroethylene. The dependence of the rate of return strain (ε'_r) on time (t), the dose of electron irradiation (D) and mechanical stress (σ) in thin films of polytetrafluoroethylene has been experimentally investigated. Significant variations of ε'_r have been found dependingon on t, D and σ. A decrease in the rate of return deformation during irradiation of the material is associated with the frictional properties between macromolecules and a change in the structure, which leads to a weaker straightening of the polymer and their poor sliding. The resulting curves for both unirradiated and irradiated material are satisfactorily described in the exponential and linear models. For dependencies ε'_r on D, these are decreasing functions, and for ε'_r on σ, these are increasing functions.

Abstract: Gas metal arc welding process has the capability of producing high quality, all position welding, and is easily adaptable for automated welding applications. Repair welding of random cracks on existing assembly/structure through automatic welding would need real time crack/gap identification and weld path generation. In this work, an image processing-based system is presented for identifying the crack geometry. Graphical user interfaces are also developed to take necessary user inputs required at different stages for crack identification, predicting weld bead dimension, and weld path generation. Based on the identified crack geometry and predicted weld bead feature, linear and curved weld path planning methodology is proposed. The proposed modules are validated for a case study by successfully generating the desired weld paths. Different natures of velocity profiles are considered to appraise the role on motion behaviour and a suitable profile is selected for reducing the jerks at sharp corners/via points on the weld path and maintaining uniform bead geometry.

Abstract: The article is devoted to the study of the kinetics of packet formation and energy distribution in the process of explosion welding. The results of experimental determination of the components of the total energy balance during explosion welding and their influence on obtaining a given part profile are presented. The kinetics of the package motion during explosion welding with simultaneous formation of a bimetallic billet with a cylindrical profile is shown.

Abstract: Various methods of gas-vortex stabilization in plasma torches for metal cutting are investigated. The influence of an angle of plasma-forming gas injection into the nozzle on kinematic characteristics of the plasma jet is shown. The increase in the radial component of the velocity at the output from the swirler makes it possible to increase the uniformity of velocity distribution and the kinetic properties of jet in the zone of influence on the cut metal. For the cutting of the thin sheet metals, it is advisable to use the technology of "narrow-jet plasma".

Abstract: Results of the design analysis carried out using computer software are presented for boundary data complying with the currently operating state-of-the-art arc steel furnace. Flow of natural gas combustion products and oxygen are reviewed for the radial and tangential burner arrangement in the working space between the wall and the electrodes. Location of high temperature fields is determined and the expected heat transfer to the charge materials through the active surface participating in heat exchange is evaluated. Precipitation degree is determined for the dust participating in scull generation on a wall water-cooled surface and significant reduction of dust effect on electrodes.

Abstract: The relationship of oscillations amplitude of the granular medium-elastic screw system whilst passing over resonance at different values of the bulk mass per unit length at different motion velocity has been studied. The relation of resonance oscillations of the granular medium-elastic screw system described by ratio α(t) and ν(t) has been shown. Based on these ratios, we plotted time variations of amplitude against quick passing over resonance.

Abstract: The aim of the paper is to evaluate numerical analysis of the fluid flow during the outflow from vessel orifices at various locations. The problems of the outflow velocities and pressure fields were well-chosen for the given purposes. The selected fluid flow problems were solved by numerical simulation using FEM in ANSYS. For numerical simulation, we used the basic steps to design an abstract model in the ANSYS virtual environment. Numerical simulation requires a geometric model complemented by physical properties of flowing fluids as well as both the initial and boundary conditions. It is then possible to calculate the velocity and pressure fields by numerical simulation for a particular fluid type. The results obtained from the numerical simulation were compared with those of the analytical solution. The results obtained from modeling and numerical simulation correspond to the actual values ​​with minimum deviations. The demonstrated type of the problem solved by numerical simulation and modeling confirmed the advantages and possibilities of flexible solutions for any combination of problems in the field of ​​fluid dynamics. Modeling and numerical simulation of fluid flow can provide results regarding the speed and the pressure fields in vessels and pipelines.