Papers by Keyword: Cylinder

Abstract: The oil industry plays a key role in the global economy, providing raw materials and energy to various industries. The performance and reliability of pumping units in the oil industry are critical to ensure the smooth production of oil and gas. Pumpjacks in the oil industry are exposed to extreme conditions such as high loads, corrosion, aggressive environments and high temperatures. The study of technological factors that affect the performance and aging of these pumpjacks shows the development of specialized materials, designs and maintenance methods adapted to such conditions. Regular repairs, replacements or breakdowns of pumpjacks can result in significant operating costs for oil companies. The study of technological factors affecting the aging and performance of pumpjack helps to optimize maintenance processes and prevent unexpected breakdowns, which leads to lower operating costs. The performance of pumpjacks in the oil industry is directly related to the safety of personnel and the prevention of environmental accidents. Non-compliance of technological factors with safety requirements can have serious consequences, including accidents and environmental pollution. Considering the importance of the oil industry, its specific operating conditions, economic and environmental consequences, the study of the influence of technological factors on the performance and aging process of pumpjacks is of high relevance and a priority task for ensuring the efficiency and safety of operations in oil industry.

Abstract: Comparative analysis of the use of the defining equations of plasticity theories obtained at the loading step in three ways is performed. In the first method, the relations between strains increments and stresses increments are obtained by differentiating the governing equations of the small elastic-plastic deformations theory between full stresses and strains. In the second method, the authors based on the proportionality hypothesis between the component deviators of strains increments and the component deviators of stresses increments without separating the incremental strain into elastic and plastic parts obtain the determining equations at the loading step. In the third method, the relations between the incremental strain and the stresses increment of the plastic flow theory are used on the basis of the hypothesis about the proportionality of the plastic deformations increments to the components of the stress deviator. Based on the analysis of algorithms for obtaining the constitutive relations and the analysis of the numerical results of the calculation example, preference is given to the second method of obtaining expressions between stress increments and strain increments without separating the latter into elastic and plastic parts.

Abstract: Knowing the stresses and pressures in the contact between two deformable solids is fundamental in order to optimize the strength and the lifetime of mechanical components such as bearings or gears. These constraints can be determined by the calculation (finite element method or Hertz theory) or by experimental methods such as photoelasticity. The objective of this study is to model and compute the stress field and contact pressure using 3D finite element software. The validation of obtained results is done by comparison with the classical results of the non linear Hertz theory between two deformable cylinders. An application to spur gears with a circle involute profile is done and also validate with the same Hertz theory.

Abstract: The present numerical study deals with the natural convection heat transfer on the surface of a vertical cylinder with external longitudinal fins. The aim of the study was to determine the effects of geometric parameters like fin height, fin number and fin shape on the heat transfer and thus obtain the optimum parameters that will maximize the rate of heat transfer have been discussed. The numerical investigation consists of an aluminium cylinder of length 1m and diameter 0.07m with air as the working fluid. It has been seen from the numerical investigation that the heat transfer increases with fin height. It is also observed that there exists optimum fin number for maximum heat transfer. Keeping the fin number, fin height and volume fixed, it was found that the heat transfer is maximum for rectangular shaped fin.

Abstract: There are so many equipment using cylinder in its application, such as bridge support column, smoke chimney, pole pillar of offshore oil drilling etc. When those kind of equipment is affected by air flow continuously, it would reducing the strength of those equipment construction. This strength reduction is caused by the drag force that is emerged due to the air flow and its direction are having the same direction with flow direction. So that it is necessary to do something to reduce the drag, one of it is by adding the rectangular ring at the cylinder surface. The rings is placed at the cylinder surface in 10⁰ sloping position and then its ring distance would be varied. The aim of this research is to discover the influences of distance variation between the ring with sloping position on the cylinder surface to the drag coefficient. This research is conducted in the wind tunnel that consist of blower, pitot pipe, U manometer, inclined manometer, digital weight, cylinder, quadrangular rings (attached on the cylinder). The cylinder is placed in vertical position within the distance between the rings is varied as L/D = 0.5, 0.67, 0.83, 1.00, and 1.17. The Reynold number based on silinder diameter D = 60 mm is Re = 3.64 X 10⁴ . Pressure distribution is determined by measuring cylinder surface pressure at 36 points with 10⁰ interval. The result of this research showed that the lowest drag coefficient value occurs at the distance between the ring of L/D = 0.5 is 0.485. The large decreasing of the drag coefficient compare to without rings is 43.5%.

Abstract: A method is presented for determining the coefficient of transverse dispersion in flow through packed beds, which is based on the measurement of the rate of dissolution of planar or cylindrical surfaces, buried in the bed and aligned with the flow direction. The underlying theory is initially explained and experiments are then described in which more than three hundred new data points were obtained. These data are for the flow of water, at interstitial velocities between 0.1 and 1.5 mm/s, through beds of silica sand with average particle sizes between 0.219 and 0.496 mm. The experiments were performed at a range of temperatures, between 20oC and 35oC, and this yielded dispersion data for values of the Schmidt number (Sc=μ /ρD_m) between 1170 and 570. For all the data reported, the ratio between the coefficient of transverse dispersion and the coefficient of molecular diffusion was shown to correlate well with the Reynolds number (Re=udρ /μ), both for beds with narrow and with wide particle size distributions.

Abstract: This study focuses on the smoothly blending problem of two cylinders whose axes are non-coplanar at the clipping planes which are perpendicular to the axes. Based on the condition that the axes were smoothly blended, we presented the necessary and sufficient conditions of the existence of the blending surface with the cylindrical helicoids tube constructed. And when those conditions were met, we presented the specific blending examples.

Abstract: This paper proposes a design of pneumatic high-pressure mud pump based on PLC control. According to this method, we design the three-cylinder reciprocating single acting pneumatic high-pressure mud pump, and give the details of PLC control system and high-pressure pump body, finally briefly describe the working principle and the experimental results.

Abstract: According to the working condition and characters of pneumatic servo system, the mathematic model of switching valve and executing cylinder controlled by pulse width modulation were built. The mathematic model was made use of in the flow regulator used on gas generator and the simulation model was built with Simulink in Matlab. According to the simulation model, the dynamic characteristic was analyzed.

Abstract: Anti-extrusion process for the cylinder of spray-formed ultra-high strength aluminum alloy is researched in this paper. The spray-formed 7xxx aluminum alloy is treated by a two-step homogenization treatment (440 °C / 12h + 472 °C / 24h) after hot isostatic pressing (HIP), and then hot compression tests are carried out for getting the stress-strain relationship under different forming conditions. Anti-extrusion process for the cylinder is improved including changing the shape of mould and billet, and numerical simulation is used for researching the anti-extrusion process. According to the distribution of strain-effective, it can be seen that the improved scheme of anti-extrusion process can get more deformation than the common scheme at the bottom. The result of anti-extrusion experiments shows that the microstructure is evenly distributed across the cylinder under the improved scheme.