Papers by Keyword: Flow Rate

Abstract: Water energy is one of the renewable energy sources with immense potential, and it is -+starting to be utilized more extensively today. The Archimedes Screw Turbine (AST) is one type of turbine that can be used to convert the kinetic energy of water into mechanical energy, and it is particularly suitable for regions with low-head water potential. This study proposes an experimental investigation to observe the performance of a newly designed double-blade Archimedes screw turbine, with shallow heads, specifically equal to or less than 1 meter. Four flow rate and four head variations were tested to obtain power and efficiency. The Taguchi method was employed to reduce the number of inputs during the testing process while still yielding more comprehensive quantitative information. The maximum turbine power obtained was 115.89 watts, and the maximum efficiency was 68.72%, occurred at a 1-meter head and a flow rate of 1035 L/min. Based on the results of this research, accurate information was obtained regarding the influence of flow rate and head on the torque, turbine power, and efficiency of the turbine. The Double-Blade Archimedes Screw Turbine demonstrates good performance and is feasible for use under head conditions below 1 meter.

Abstract: Renewable energy has become a promising alternative energy due to innovations that have reduced costs and realized the future of environmentally friendly energy. Hydroelectric power plants are one of the most promising renewable energy in Indonesia, especially in areas with many rivers. In many low head water flow locations, Archimedes Screw Turbine (AST) may be more cost-effective, with lower installation and operation costs than alternative hydroelectric power systems. Although many theoretical and experimental investigations have been published regarding the implementation of this AST over the past decade, there has been no experimental evaluation in the literature for heads below 1 meter. This post presents test results from Single Screw Archimedes turbine with a difference in flow rate of 106 l/min, 291 l/min, 594 l/min, and 1035 l/min and head variations of 0.7 meters, 0.8 meters, 0.9 meters, and 1 meter. Maximum turbine power of 93.93 Watt at 1035 l/min at head 0.7 meters. The results provide new insights into the performance of the Archimedes screw turbine efficiency under the 1-meter head. The flow rate is comparable to torque and power increases as the turbine entry flow increases.

Abstract: The enhancement of thermal stratification in solar storage tanks is a crucial aspect of advancing solar energy technology. This study presents an experimental investigation conducted on a vertical cylindrical hot solar water storage tank operating in a dynamic mode, involving simultaneous charging and discharging. The experiment aims to assess the impact of varying inlet water flow rates (4, 6, 8, 10 L/min) on thermal stratification within the tank and explores strategies to mitigate heat losses to the environment and minimize mixing effects caused by the inlet fluid flow. The experimental setup incorporates insulation and an inlet port diffuser section to optimize the distribution of inlet water during the charging and discharging states. The results reveal that the utilization of an inlet port diffuser significantly improves thermal stratification by reducing heat losses and minimizing mixing effects, as evidenced by improved Richardson numbers. Additionally, this study contributes to the development of a compact solar domestic hot water (SDHW) solution.

Abstract: The chemical vapor deposition method and the method using copper are suitable for high-quality large-area graphene synthesis. Here, we present methane flow conditions for obtaining high-quality graphene over a large area. The conditions of gases other than the flow rate of methane were fixed, and the graphene synthesized by adjusting the flow rate of methane and the exposure time of methane was verified through the Raman spectrum. When the methane flow rate was 5 sccm, the growth of graphene was island-shaped and made into a multilayer graphene. When the methane flow rate increases to 8 sccm, the Irish growth of graphene disappears and stably grows into a single layer. However, if the flow rate exceeds 9 sccm, Irish growth disappears. However, in order to minimize the area where graphene in the multilayer is synthesized, the methane exposure time was analyzed in units of 10 minutes from 5 minutes to 25 minutes. When analyzing the I[2d]/I[g] value and I[d]/I[g] value of the Raman spectrum, single-layer graphene of a large area could be observed.

Abstract: The design of protected fire escape routes is a process in which a number of technical aspects that are set by Czech technical standards must be considered. The assessment of protected fire escape route's ventilated premises is subject to strict values, which when designed, or when created additionally, often force us to resort to specific measures, like a forced ventilation, enlargement of openings, which leads to expensive construction. This paper focuses on the use of so-called engineering methods to solve this problem, specifically the computational fluid dynamics method, which finds application in the revalidation of otherwise unmet ventilation criteria.

Abstract: The influence of temperature, flow rate, PH value, and oxygen content on the corrosion law in the carbon dioxide salt solution of J55 oil casing was investigated by the corrosion weight loss method. The results showed that with the increase of temperature, the corrosion rate of J55 steel first increased and then decreased and the corrosion rate reached the maximum at 100°C. The corrosion rate was closely related to the formation of corrosion products. The increase of the flow rate speeded up the transfer rate of the corrosive medium to the metal surface and hindered the formation of FeCO₃ on the metal surface. The corrosion rate was significantly higher than the corrosion rate under static conditions, and as the flow rate increased, the corrosion rate of J55 steel increased accordingly. The increase of the pH value gradually reduced the concentration of hydrogen ions, and cathodic reaction of hydrogen ion depolarization during metal corrosion process was inhibited, and the tendency to form an oxidizing protective film on the surface of carbon steel increased, thereby reducing the corrosion rate of metals. With the increase of oxygen content, there were both hydrogen evolution reaction of CO₂ and oxygen absorption reaction caused by O₂ in the cathode process. The corrosion rate of J55 steel gradually increased, and at the same oxygen content, the higher the carbon dioxide content, the greater the corrosion rate is.

Abstract: During the manufacture of plastic micro-pipe, a certain volume of gas should be properly injected into the inner cavity to overcome the collapse and adhesion problems. In this work, the extrusion forming of plastic micro-tube under the role of inner cavity’s gas were numerically studied. At the same time, the effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-pipe was also numerically investigated by using the finite element method. A kind of 2D two-phase fluid geometric model and finite element mesh were established and some reasonable boundary conditions and material parameters were imposed. Under a fixed volume flow rate of melt, different flow rates of inner cavity gas were imposed on the inlet of inner cavity’s gas. The extrusion deformation profile and deformation ratio of plastic micro-pipe under different flow rates of gas were all obtained. To ascertain the mechanisms of effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-tube, the flow velocities, pressure, shear rate, normal stress, and the first normal stress difference of melt all obtained and analyzed. Numerical results show that with the increase of inner cavity’s gas flow rate, the radial velocity, axial velocity, pressure, shear rate, normal stress, and the first normal stress difference of melt all increase, which makes the extrusion deformation become more and more serious. In practice, reasonable controlling of the inner cavity’s gas flow rate is very important. In the other hand, it can adjust the size of extruded plastic micro-pipe.

Abstract: Water is a chemical compound with chemical formula H₂O. By the electrolysis proses, water can be split constituent elements, namely hydrogen (H₂) and oxygen (O₂). In this study, an electrolyze system used six pieces of electrodes which made from 304L SS for electrolysis process for both of distilled water and adding catalyst NaHCO3 (Sodium Bicarbonate) on distilled water. The results indicated that electrolysis process on distilled water consumed power of 353.52 Watts to produce Brown’s gas of 0.00123 l/s. Whenever, NaHCO3 was added into distilled water with the mass fraction of 1.33% consumed power decrease of 27.89 Watts and Browns gas was produced 0.0017 l/s. The efficiency of distilled water had the greatest efficiency only 5.53% by using current of 2 Ampere and power reached 31.043Watts. While the addition of catalysts had the greatest efficiency reached 40.29% in the use of mass fraction of catalyst 1.5%, 6 Ampere currents and power of 19.829 Watts.

Abstract: The coolant (water) pump assumes an important role of cooling system in IC engines. With upgrading of the engine power by turbocharging and turbo inter cooling, the water pump capacity needs to be increased corresponding to the power. This capacity enhancement has to be achieved without calling for a major change in the existing water pump, envelop and related fitment details. This requires a clear understanding of centrifugal pump for its performance parameter. One such engine is upgraded by turbocharging from 195PS to 240PS @2200 rpm. Improving water pump flow by changing the impeller dimensions, impeller casing, increase the suction, delivery pipe diameter had been done. Validation of the water pump in its actual engine installation was taken up as a part of the research work. Flow rate comparison of the new pump with the existing pump was made and the results were analyzed. The new water pump gives better flow rates for the engine speeds up to1800 rpm, beyond which the flow rate is slightly lesser than the existing pump.

Abstract: In micro-scale flow condition, the flow rate and fluid extrusion expansibility are always affected by the wall slip between the fluid and tube wall. In this research, a wall slip model based on a micro-tube flow was developed, and then the wall slip effect on the viscous fluid micro-extrusion process was explored by computational fluid dynamics (CFD) with different extruding pressures. The results showed that wall slip make the fluid resistance and expansibility decrease, and the fluid mass flow rate increase.