Papers by Keyword: Orifice

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.

Abstract: This study reports on effects of tapered metering pins on a magnetorheological (MR) fluid subjected to shock loading. Using four types of tapered metering pins, we conducted drop impact tests and qualitative analysis of effects of tapered pins on an MR fluid with a magnetic field applied around an orifice area. We measured the displacement of a piston and calculated velocity and acceleration from the measured displacement. The four different tapered pins changed a piston stroke to bring the impacting mass to rest. The results indicated that the shape of the pins has an effect on the entire process of shock absorption, whereas magnetic field strength has an effect on the post-peak behavior only. These results show that a tapered metering pin has applicability to a shock absorber using an MR fluid.

Abstract: The turbulent flow in orifice plate was investigated and solved numerically using 3-D Navier-Stockes (N-S) equations by employing commercial CFD code ANSYS. The N-S equations were solved for unsteady flow of an orifice plate at different values of Reynolds number, Re=ρVDμ, and different aspect ratios, β=dorificedpipe. Physical parameters such as velocity, differential pressure, and vorticity and mechanical properties such as stress, strain, and total deformation were examined for Reynolds numbers of 10000, 20000, and 30000 and at aspect ratios β of 0.2, 0.4, and 0.6. It was found that as Reynolds number increases, the velocity increases while the differential pressure shows very steep jump across the orifice. As aspect ratio increases, the maximum pressure declines. The vorticity patterns show that images of very condensed lines. At certain aspect ratio, the differential pressure increases as Reynolds number increases.

Abstract: Orifice meter is a flow measuring device which is widely used in various industrial applications. Although the device gives accurate measurement during steady flow, measurement errors related to square root and sampling errors are unavoidable if pulsations exist. This research investigatesand improves the performance of an orifice plate flow meter under pulsation effects. A simple model for the pulsating flow through an orifice meter is presented. Square root error (SRE) is estimated. Sampling errors (SE) are reduced by proper selection of the averaging time.

Abstract: The plant industry is required to measure flow rate more accurately to meet plant operation and cost accounting objectives. The opposing concern of improving flow meter accuracy is resolved by using flow conditioners. The distance of implementation of flow conditioner upstream of the orifice plate flowmeter is also need to be addressed. Hence, in present study, an analysis of the porosity of fractal flow conditioner towards orifice plate flowmeter’s accuracy and the best distance of fractal flow conditioner upstream of the orifice plate flowmeter was determined. In an experimental work, a different porosity of the fractal flow conditioners were installed with different distance upstream of the orifice plate in conjunction with the different disturbances to assess the effects of these devices on the measurement of the mass flow rate. Data gained for all the plates showed that there is increment of pressure drop and change in discharge coefficient of the orifice with lower β value of fractal flow conditioner. Good comparisons with the previous experimental work demonstrate the fractal flow conditioner can preserve the accuracy of metering up to the level required in the standards.

Abstract: In this study, a hydraulic servo system for mold oscillating mechanism was investigated. In order to check the efficiency and the stability of system, its geometrical designs, which change the natural characteristic of system, including a spool volume, area of piston, and so on were analyzed by a non-linear model. The model was composed of the equation of orifice, the continuity equation, and the force equilibrium including a variable effective bulk modulus belonging to operating oil, gas, and cylinder. All simulations were conducted by the MATLAB SIMULINK, and simulated as specific conditions corresponding real operation conditions in the steel industry. According to the analysis, the relation between a controller, servo design, and system performance was investigated with physical means. And, the fact that not compared to other design variables, the entrance shape on spool was dominant to determine the stability and the performance of system, was found. Furthermore, a fault detection method, and optimization problem including this work were discussed.

Abstract: A solution could be made supersaturated when the physical conditions was altered. The supersaturated gas would form bubble to bring the solution back to the equilibrium condition. Bubble would first nucleated and then growth in the solution. This work was aimed to simulate the bubble formation across an orifice, with sufficient pressure drop. The CO₂ was assumed to be made saturated at 6 atm in water, and formed bubble when the solution flowed across the orifice. As the CO₂ bubble formed across the orifice, the volume of the CO₂ gas occupied almost the whole space in the orifice. The mass of the dissolved CO₂ in water had decreased too as it had transferred into gas CO₂.

Abstract: This paper deals with the improving lay of finish and the superfinishing of the nozzles which is used in plasma cutting operation. This is basically alternative solution to present finish obtained by turning, drilling and reaming of the profiled bores and orifices. The advance micromachining process were developed, known as Abrasive Flow Machining (AFM) which is capable to altering the orifice (nozzle of plasma cutting machines) so that present process is to be improved without altering the geometry of the component. The effects of different process parameters such as number of cycles, concentration of abrasive, abrasive mesh size and media flow speed, surface finish are studied here. The design of the experiments 16(2⁴) provides two levels for each variable. These levels are taken into consideration for finding out the effect of variation of parameters on the surface roughness of the copper orifice. The objective of paper is to learn how each parameter is considered for Abrasive Flow Machining such as: abrasive concentration in media, number of cycles, abrasive mesh size and media flow speed affects the surface roughness of copper orifice also to find out the mathematical relationship between surface roughness value and process parameters. Analysis of Variance (ANOVA) for the experimental data has been carried out and optimizations of abrasive flow machining process parameters were done. Also Analytic Hierarchy Process (AHP) done here for selecting hierarchy process parameter .Capabilities of the machine ultimately improved with the new technology developed.

Abstract: Absorption cold source in the vehicles differs from ordinary absorption cold source especially in its narrow space and relatively compact arrangement. In this study, CFD simulation technology, simulation and analysis of spray flow field in an absorber of automotive absorption refrigerator is carried out to verify the effectiveness of packings. This could lay a foundation for making further improvement on performance of car's absorption cold source

Abstract: In this experiment, the cold mass fraction, cold temperature difference and isentropic efficiency of Ranque-Hilsch Vortex Tube were investigated and measured. Three different inlet pressures (absolute) (296633 Pa, 394699.5 Pa and 492766 Pa) and 2 type of orifice diameter (4 mm and 5 mm) were used. 5 mm orifice gives higher value of cold mass fraction (μ_c = 0.7067) compare to 4 mm orifice (μ_c = 0.3264). It is also no significant effect in cold mass fraction by changing three difference inlet pressures. 4 mm orifice has higher cold temperature difference (ΔT_c = 18°C) compare to 5 mm orifice (ΔT_c = 8°C) at highest inlet pressure (492766 Pa) that were used. 4 mm orifice has higher isentropic efficiency (η_isen=0.17545) compare to 5 mm orifice (η_isen=0.0834). For both orifices, the highest isentropic efficiency was obtained when the lowest inlet pressure (296633 Pa) were applied.