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Oil wells can naturally produce reservoir fluids to the surface. Over time, the reservoir pressure decreased due to the consequences of producing fluid into the surface. This can result in the well being unable to produce naturally and have to use the artificial lift method. The continuous gas lift method was chosen by considering the availability of a compressor, gas injection source, gas-oil ratio, oil gravity, and overcoming the corrosion problems, sand, and gas production. The continuous gas lift design was carried out in three wells: the F-29 Well, I-10 Well, and A-04 Well. Reducing the wellhead pressure is an option to increase the production of the gas lift system. In the design of the continuous gas lift method, the well has not been able to produce oil according to the target of 70% AOF (absolute open flow) even though the wellhead pressure is lowered to 60 psi, but it showed that this method can increase production significantly. However, there must be further economic studies to do this, considering that the F-29 Well, I-10 Well, and A-04 Well have low reservoir pressure and relatively high water cut. After the reservoir pressure decreases, continuous gas lift is changed to intermittent gas lift because producing a large amount of oil at very low reservoir pressure with a large injection flow rate is considered less efficient. The intermittent gas lift is designed by changing the orifice into a PPO (production pressure operating) valve to inject gas with a particular cycle. [ABSTRACT FROM AUTHOR]

This study uses solid refused derived fuel (SRF) from municipal waste in a dual-reactor fluidized bed (DRFB) for the gasification process. Gasification which separates the process of endothermic and exothermic reactions is the focus of the development of gasification technology today. In addition to optimizing fuel conversion, the DRFB system can also recirculate the combustion gas, namely CO2, to the gasification reactor as a function of the gasification agent (CO2 loop). In this study, oxygen (O2) was used as an agent gas to reduce the appearance of NOx emissions when using air and to increase the production of CO syngas. The gas composition of the agent was varied from no oxygen (I), 25% oxygen (II), 50% oxygen (III) and 75% oxygen (IV). The city waste RDF used has a composition of 94% organic and 6% inorganic with a size of 1-5mm. The performance results were obtained in variation III with the highest solid to gas conversion (FCR) value of 0.685 kg/hour with a syngas composition value of CO=4.25%; CH4=1.73% and H2=16.43% and a gasification efficiency value of 48.99%. [ABSTRACT FROM AUTHOR]

The special injection molding process GITBlow combines the characteristic features of injection molding and blow molding and enables the production of complex hollow body structures with low wall thickness and connected functional surfaces in one process. In the first step, a preform is created using the described gas injection technology. In the second step, this preform is further formed by a second pressurization similar to blow molding after the mold cavity has been enlarged. This results in a biaxial stretching of the preform material without further melt displacement. The advantage of the GITBlow compared to the underlying single processes GAIM and blow molding as well as other special processes is the following aspects: Independent of component geometry, material and process control, the gas injection technology has a gas limit pressure from which a maximum cavity / component cross section ratio is achieved. As a result of the second inflation process, this value can be significantly increased with the GITBlow process. Only blow molding allows similar or even lower wall thicknesses, but here the geometrical design freedom with regard to the connected functional elements and surfaces is severely restricted due to the process. The results obtained so far at the University of Paderborn have shown that, when simulating the GITBlow process, a division into the three characteristic process steps of the process is target-oriented. This means that three successive simulation steps are carried out, which are oriented to the process sequence. These are in detail: 1) Preform production by means of gas injection molding; 2) Temperature compensation by heat transport; 3) Inflation by means of a second gas injection In the first years of the project, the focus was on the simulation of the behavior of amorphous materials. The current goal is to investigate the blowing behavior of semi-crystalline materials in the GITBlow process. For this purpose, strain tests were carried out at typical GITBlow strain rates, the results of which are now to be integrated into the description of the process and shall be described in this thesis. [ABSTRACT FROM AUTHOR]

Detection of the target gas using the sensor can be carried out in a static headspace where gas is not flowing but is injected or in a headspace where gas is flowing. The headspace with flowing gas has the advantage of repeatedly doing gas injection and flushing processes. This paper describes the dynamic headspace design with gas flow. The chamber headspace design uses hollow aluminum with an aperture of 3.8 x 3.8 cm. At one end of the headspace, the DC fan is installed, and the other is connected to the controlling valve to allow the gas injection and air flushing. The target gas is injected into the headspace at an adjustable rate. The gas is sucked in and discharged using a DC fan. The gas flow rate is controlled via the DC fans Pulse Width Modulation (PWM) setting. Using the PWM setting, the gas flow rate is obtained in the range of 2.81 x 10−6 m3/s – 12.06 x 10−6 m3/s with PWM duty cycle of 20%-100%. Airflow velocity control is carried out using a microcontroller STM32F401. The flow rate was calibrated to a mass flow meter sensor. [ABSTRACT FROM AUTHOR]

Well CAT-07H is a producing oil well located in Cath Offshore Field. This well hasbeen producing using gas lift method which its injection gas is supplied by COM-182 compressor. In June 2019, the production of this well was interrupted by the fault of COM-182 which initially supplied 1100-1300 psi injection pressure at CAT-07H casing to only 800-1000 psi after being repaired. Due this change of injection parameter, CAT-07H was no longer able to be produced due to insufficient injection pressure. In the other hand, the well having relatively high water cut (75%) and depleted reservoir pressure made this well can no longer flowing naturally. The most possible solution for this problem is to optimize gas lift injection depth to match the new supplied gas pressure. In this paper CAT-07H is the sample well candidate to be evaluated for GLPO installation. CAT-07H is initially a gas lifted well which receive gas from COM-182 compressor. Due to decrease in performance of COM-182 compressor, gas parameter received on CAT-07H from COM 182 is no longer suitable with existing gas lift installation. Based on evaluation, gas pressure generated from this compressor decreases from 1100-1300 psi range to 800-1000 psi range. Based on this data, gas lift optimization is required to adjust gas lift on CAT-07H to meet the new pressure range. 800 psi is used as design parameter with maximum injection gas rate of 1 MMSCFD. Based on the evaluation in this thesis, it is found that gas lift can be optimized using GLPO method by changing the injection point to 2900 ft with punch port diameter if 0.15 inch which can be acieved using 1606 L puncher. After the optimization using GLPO on CAT-07H, production rate can be optimized to 2532 BFPD with net production of 633 BOPD. [ABSTRACT FROM AUTHOR]

Miscible CO2 injection is one of the enhanced oil recovery (EOR) methods by expanding the volume of oil, reducing viscosity and density, reducing interfacial tension, and extracting oil into the CO2 phase which can reduce the mobility ratio of the oil. The miscible CO2 injection method chosen is the Water Alternating Gas (WAG) method. The WAG method is the latest technology to increase sweeping efficiency during injection, minimize the amount of CO2 that must be used, reduce the mobility ratio of oil and slow down the breakthrough that generally occurs in the continuous CO2 injection method. The purpose of this study was to determine the effect of cycle time and the optimal WAG ratio on the CO2 miscible WAG injection method to obtain the highest recovery factor value in field X. Cycle time and WAG ratio are important parameters in WAG CO2 injection because cycle time is the transition time between water injection and CO2 gas injection and WAG Ratio is the ratio of the amount of water injection rate and CO2 to be injected into the reservoir. If too much water is injected, the microscopic efficiency will decrease, while if too much CO2 gas is injected, it will cause a low sweep efficiency. Research methodology with three-dimensional simulation software CMG compositional. The results obtained from the CO2 miscible WAG injection method are the most optimal slug size using 2 PV with an inverted five spot well pattern, in a cycle time of 90 days (3 months), and the optimal WAG ratio using a 1:3 ratio (injection water rate 20,036). [ABSTRACT FROM AUTHOR]

The research work presents the flow characteristics of the steady flow field of a rocket engine with a nozzle, the objective of the work is to consider one of the rocket engines, simulate and present the variation of Mach, Density, Temperature, Thrust deflection, change in momentum due to the thrust vectoring. A numerical analysis was carried out to characterize the nozzle flow field of secondary injection thrust vector control (SITVC), and a simulation results was set out to analyze the impact of switching the injection position on the SITVC nozzle fluid flow structure and SITVC performance. Parameters. Due to the complexity of the rocket flow investigation, most of the research works are performed using the computational tool. And due to the advent of Computational Fluid Dynamics, the studies involving the fluid flow problem for complex systems has been tremendously helpful. Therefore, the research work has solved numerically the compressible 2-D steady Reynolds Average Navier Stokes equation. [ABSTRACT FROM AUTHOR]

Porous ceramics offer excellent mechanical, abrasion, chemical, and thermal characteristics. In addition, these porous network ceramic structures have a less density, mass, and thermal conductivity. In this work an attempt has been made to develop a porous ceramic material based on pure aluminium added with fly ash based cenosphere added with suitable binder bentonite. Bubble type melt gas injection method is adopted for production of porous ceramic foams. Aluminium powder percentages are varied for 60, 65, 70 and 75 wt.% and the porous structure obtained is assessed using macrostructure evaluation. Also, the percentage porosity of the fabricated ceramic foam is evaluated as per ASTM guidelines. It is found that with higher aluminium percentage the percentage porosity obtained higher with a dendritic like structure. [ABSTRACT FROM AUTHOR]

The influence of foreign gas injection on the boundary layer stability of the Mach 6 nozzle of the Transit-M wind tunnel is investigated within the framework of the linear stability theory. The N-factors of the Görtler vortices and the first and second Mack modes are obtained. For a given nozzle, the most unstable disturbances are Görtler vortices. It is shown that the light gas injection leads to a significant slowdown in the growth of Görtler vortices, and the higher the mass flow rate, the stronger this effect. However, an increase in the mass flow rate of a light gas leads to an acceleration of the second mode growth in the boundary layer of M = 6 nozzle; the second mode can lead to a transition earlier than the Görtler vortices at some parameters of the injections. Heavy gas injection accelerates the growth of Görtler vortices and second mode disturbances. The growth of the first Mack mode is slower during the injection of both light and heavy gases. [ABSTRACT FROM AUTHOR]

This work is devoted to the study of the influence of light gas injection on the stability of the boundary layer on the plate at Mach number M = 5.4. The boundary layer stability is calculated within the framework of the linear stability theory. Boundary layer equations in self-similar coordinates and the Fluent program from the Ansys package are used to calculate laminar boundary layers. Gas injection is simulated from the plate surface. It is shown that the injection of light gas leads to the stabilization of second mode disturbances. First mode disturbances are destabilized in the injection region and stabilized downstream of the injection region. [ABSTRACT FROM AUTHOR]

Due to economic and ecological trends, materials used in the automotive industry are expected to be lightweight. One of the most important advantages of lightweight materials is a reduction of raw material consumption, which results in lower production costs. In the automotive and aviation industry, one of the most important features of lightweight material is its density. Obtaining material with lower density allows to reduce a total weight of a vehicle, which causes improved performance and lower fuel consumption. One of the key solutions used to produce lightweight parts in the automotive industry is microcellular injection molding (MIM), which allows obtaining a part characterized with microcellular structure, consisting of plastic and gas pores inside of a part. The most important challenge in creating lightweight materials is to achieve comparable mechanical properties to the state before density reduction. This kind of result is possible to achieve by the control of porous material's structure, primarily gas cells size, amount and distribution. This work presents the influence of gas injection parameters on a part's structure, examined with use of 2 injection simulating tools and in actual experiment, where the structure was tested in use of computed microtomography. The second aim of the work was to compare results obtained in 3 different ways, which were: Moldex3D simulation, Cadmould simulation and an actual experiment. [ABSTRACT FROM AUTHOR]

To increase the active volume of injected gas, there were analyzed current state, as well as technological and thermodynamic parameters of all wells and field equipment at the Karadag Underground Gas Storage facility. To determine the total volume of injected gas, a preliminary calculation was carried out for each of the Underground Gas Storage wells. Based on the results of field research carried out at the Karadag Underground Gas Storage facility, a number of scientific and technical measures have been developed to improve the efficiency of the active volume of injected gas and there have been presented technological result and economic efficiency of their implementation. The optimal thermodynamic and technological mode of well operation was selected during the period of gas injection and withdrawal at the Karadag Underground Gas Storage facility. [ABSTRACT FROM AUTHOR]

Underbalanced drilling operation has been discussed which is classify as unconventional drilling method by making the bottom hole pressure lower than the formation pressure. To accomplish underbalanced, with lightweight drilling fluids, gas injection down the drill pipe, and gas injection through a string. It categorized in relation to the density of the fluids into five main fluid types based mainly on equivalent circulating density (gas, mist, foam, gasified liquid and liquid). Fluid type is detect by the boundary conditions of the drilling system. The economic feasibility and the comparison to the conventional drilling was covered with case studies for x well used to show beneficial effectiveness circumstances to do underbalanced drilling. The operation has been simulated in Geological formations of Egypt which help to predict whether it is possible to achieve a stable underbalanced condition by showing changes of bottom hole pressure with specific data such as design for drill string, reservoir data, mud program and well trajectory. The study is helpful to rise recovery of hydrocarbon, to reduce problems related with aggressive formation destruction and decreased cost when related with the cost of conventional drilling for the same formation. Further aids of this method help in the decrease in drilling time, larger penetration rates, increased bit life, a fast-productive reservoir areas indication, avoid loss of circulation and differential pressure sticking. One of the most significant phases of the underbalanced drilling operation is the planning phase. The applicant reservoir must assess for its appropriateness for underbalanced drilling before undertaking an Underbalanced Drilling project. It used when the formation has a flow that could be ranges under control while drilling. So, it can be used in Southern Iraq if there is much more understanding of the formations with instructions. [ABSTRACT FROM AUTHOR]

Within the oil and gas industry there are a number of key factors which are important in carrying out a review of any reservoir which include ensuring that running expenses and down time are kept to a minimum, the process of ensuring maximum yield from a well, the development of the oil field and starting from the reservoir and finishing at the well-bore assuring the consistency of the flow over the complete production system so the production predictions for the complete operation are the final necessary piece of information. For the purposes of this research exercise a specific field was selected which was not opened fully until 2007 but was drilled in the 2000s and the objective is to identify how the gas lift process might be used to improve the production capacity of the initial wells within the field. In other words, the overall capacity of the field in terms of production capability into the future under a variety of different operation procedures is the main focus of this research exercise so that a proper evaluation can be carried out. In order to do this, it was necessary to gauge the best production rate within the design parameters and to develop the optimum gas lift using the PROSPER software program and the best parameters to achieve this analysis were the comparisons between the estimated and the actual observed pressures. Using these comparisons, it was obvious that the Beggs-Brill and Petroleum Expert2 methodology was the best and it was used in the gas lift design and from this the following parameters were optimised; the most efficient rates for gas injection, oil production, amount and depth of valves and the necessary pressure for opening and closing valves. Furthermore, the detail in terms of ratios of gas to oil and how water-cut affects this were analysed as well as reservoir pressure the range of gas lift techniques. It has been observed from the simulation that the gas lift method is more economically beneficial as long as the well continues to produce when the reservoir pressure 5300 psi and water cut 60% if the gas lift process has been applied. The results of gas lift design shown that the maximum oil production rate is (1260) STB/Day with optimum gas injection rate of (3) MM Scf/Day. [ABSTRACT FROM AUTHOR]

Gas injection is an efficient oil recovery technique if it is properly design, executed and surveyed. The injection of gas into a reservoir can be designed for pressure maintenance or gas flooding for oil displacement. This article presents the evaluation of the Gas Injection Project for Pressure Maintenance in R2U YS-32 reservoir of Central Yopales Oil Field through a reservoir characterization study that consisted of four phases: Data Compilation and Validation, Reservoir Static Model, Reservoir Dynamic Model and Gas Injection Performance Evaluation. The first phase was directed to compilate and validates the data available, which allowed detecting the additional information needs and establishing a reliable database for the following phases of the study. The Static Model consisted in geologically characterizing the reservoir using a conventional methodology. This allowed validating and/or reinterpreting the main stratigraphic and structural characteristics of the R2U YS-32 reservoir, thus determining the communication between the R2U YS-32 and R2 YS-68 reservoirs. Now they represent a single reservoir called R2U YS-32. Through static modeling, original oil in place (OOIP) of 33.35 MMbbl was volumetrically estimated. The Dynamic Model comprised the monitoring of production, injection, and pressure of the reservoir. This phase was developed, in large part, parallel to the Static Model phase. Through dynamic modeling, it was determined that the reservoir was initially saturated at a pressure of 1490 psi with a bubble pressure of 1617 psi and a gas cap size of m = 0.1255. It was also determined that the main mechanisms of production during the natural depletion period were the expansion of fluids and water intrusion, while gasinjection is the main mechanism during the secondary recovery. In addition, in this phase the volumetric OOIP was validated satisfactorily by material balance, being estimated at 33.33 MMbbl. Results showed that the gas injection did not achieved the expected results, basically because it did not manage to maintain reservoir pressure, minimize the advance of the aquifer, nor evenly sweep the oil towards the producing wells. This was mainly due to that during the first years of the gas injection, a large part of this was produced through the YS-68 well, which is connected to the reservoir's gas cap through a non-sealing fault. Additionally, the required gas volumes were not injected during the rest of the injection period. Since the reservoir has not produced since 2002, it is suggested to analyze different alternatives scenarios to reactivate the reservoir oil production including techniques like cyclic water injection or dump flooding that had been studied and planed in reservoirs/fields close to the Yopales field. [ABSTRACT FROM AUTHOR]

On the basis of the presented mathematical model, the problem of the formation of gas hydrate during the injection of gas (methane) into a porous layer of finite length, initially saturated with methane and ice, is considered. The cases when hydrate formation occurs both on the frontal surface and in the extended region are investigated. It is established that a part of the gas hydrate formed in the extended region can dissociate in the future, and the extended region of hydrate formation can degenerate into a frontal surface. [ABSTRACT FROM AUTHOR]

On the basis of the presented mathematical model, the problem of the formation of a gas hydrate during the injection of gas (methane) into a porous edge of the bed length, initially saturated with methane and ice, is considered. Cases where hydration formation occurs both on the frontal surface and in an extended area have been investigated. It has been established that a part of the gas hydrate formed in an extended region can further dissociate, and the extended hydrate creationregion can degenerate the military surface. [ABSTRACT FROM AUTHOR]

At the time of primary production, a large amount of oil reserves are left in the reservoir. The purpose of this research is to determine the results obtained from the CO2 injection and water injection methods.Therefore, CO2 injection is one of the Enhanced Oil Recovery (EOR) methods used for the remaining oil reserves in the reservoir. Water injection is used to maintain the energy reservoir to ensure that oil is pushed from the reservoir into the production well. In this study CO2 and Water Flooding were analyzed using a literature review from previous studies and the results of the simulation of these 2 methods.. The method used in this research is the observation of the mechanism and the results obtained with the two methods. The results showed that the oil production at the beginning of gas injection increased significantly and was almost the same as water injection of 5,000bbl/day. The decline in oil production using CO2 gas injection was faster compared to water, due to its low small viscosity and gas density. In addition, the injection of CO2 gas led to the recovery of oil from a larger one with a difference in acquisition of 1-2%, which would be greater when the injection volume is increased. It was concluded that water flooding may be injected at a depth of less than 1000ft with an average permeability of 10mD and oil saturation of less than 5%. Meanwhile, CO2 injection may be injected at a depth of over 2500ft. Therefore, both types of injection were suitable for sandstone or carbonate rocks. From the results of this study it can be concluded that the difference between the two methods is the type of miscibility where CO2 injection is miscible, while water injection is not mixed. These two things have two different mechanisms. [ABSTRACT FROM AUTHOR]

The theoretical and experimental investigation of the effect of the heavy gas (sulfur hexafluoride) blowing into the boundary layer on the hydrodynamic stability to controlled perturbations of the supersonic flat-plate boundary layer at Mach number 2 have been carried out. Artificial perturbations have been entered in the model's boundary layer by using a harmonic point glow discharge perturbation source. It is obtained that heavy gas blowing stabilizes the supersonic boundary layer. In experiments at the excitation frequency f = 14 kHz, unit Reynolds number Re1 = 3×106 m−1 and streamwise coordinate x = 90 mm, it was obtained that for gas injection rate Q = 0.12 g/cm2 there is a stabilization of perturbations for all spanwise wave numbers, i.e. the complete stabilization of perturbations – for all wave numbers, the spatial disturbance amplification rates are less than zero. [ABSTRACT FROM AUTHOR]

Surface modification of carbon-based nanoparticles has become essential and is challenging for bio-applications. The submerged arc discharge method is a promising technique because liquid can be used as the medium for both synthesis and surface modification at once. Submerged arc discharge using gas injection is rarely applied; therefore, the surface characteristics of the nanoparticle product have not yet been reported in detail. In this study, we investigated those surface characteristics using Fourier transform infrared (FTIR) spectroscopy to analyse the functional groups attached to the carbon nanoparticle produced by submerged arc discharge in ethylenediamine medium under different gas injections of N2 and Ar. The FTIR analysis indicated successful amine-surface modification of nanoparticles produced in arc discharge in the ethanol-ethylenediamine medium. This conclusion was reached from the observation of several absorption peaks at wavenumbers of 1020 cm-1, 870 cm−1, and 700 cm−1 as C-N vibrations, NH2 wagging and twisting, and NH2 bending, respectively. The effect of variations of gas injections influences the characteristics of FTIR spectra. Altogether, the representative peaks of amine groups have different performance signals due to variations of gas injections. [ABSTRACT FROM AUTHOR]

Injection foam molding provides the industry with advantages from production through to the life cycle of plastic components. Despite numerous applications, many questions regarding the fundamentals of this technology are fraught with uncertainty. One aspect of supreme importance is the relationship between the gas content during processing and its influence on the process and part performance. To refine the foaming technology and to comply with modern market requirements, it is crucial to understand this dependence, as proper process design and tailoring of mechanical properties require this knowledge. This work represents a thorough investigation of the influence of CO2 content on both the process and the produced components. Using talc filled polypropylene in a MuCell® process, initially the dynamic solubility limit, i.e. the ultimate amount of gas dispersible in the polymer melt during an injection molding process, was determined via a bulk modulus methodology. During this procedure, foamed plates were molded at different CO2 contents. Processing parameters, morphology and bending behavior of the produced plates were monitored and measured. The results show interesting mechanical behavior, especially close to the determined solubility limit. Based on these outcomes our experiments clearly argue for larger gas contents in physical foaming, which also benefit injection pressure/work or torque during processing. In contrast to these findings, trials with a chemical blowing agent (also yielding CO2) were carried out with the same material. The TGA of the blowing agent yielded an astonishing difference regarding gas concentration in the melt of one order of magnitude compared to physical foaming. In spite of the vanishingly small amounts of gas in chemical foaming, a fine morphology developed. This study provides novel insights into the complexity of injection foam molding, critically assesses gas contents during processing but also poses new questions.. [ABSTRACT FROM AUTHOR]

Such extreme work conditions as underwater offshore production on the Arctic shelf fundamentally new types of compressor units is required using. The efficiency criteria for the Arctic gas producing complexes are met by the compressor based on the gas-dynamic vibration scheme, the principle of kinetic compression and volumetric gas injection during the vibrational piston-nozzle motion in the sound frequency range. The complete absence of mechanical friction of the structural elements the advantage of the compressor. This paper considers a multi-stage scheme of the compressor with electromagnetic actuator for hydrocarbon production and the recent health estimated analysis on the calculation kinetic magnetoelectric compressor compression volumetric discharge as an analogue wave compressor basis. [ABSTRACT FROM AUTHOR]

The subject of research was an opposed reciprocating compressor (RC) providing gas injection into the underground gas storage. Issues concerning implementation of compressor start-up conditions to recirculating line have been considered. As a tool, the compressor-network analysis method is used, which consists in determining the system operating points through matching characteristics of the reciprocating compressor and the network, for which in this case the recirculating line with the control valve is considered. Recommendations have been received to select a control valve type for the reciprocating compressor operating in both single-stage and two-stage modes. [ABSTRACT FROM AUTHOR]

The foam injection molding process provides a multitude of advantages both during production and throughout the life cycle of foamed components. Yet still there are many uncertainties concerning the conditions inside the cylinder during gas injection. For a better understanding of these processes, the solubility of gases in polymers is crucial. In current literature, almost exclusively static solubility is investigated. It is questionable whether results from static solubility measurements are relevant for highly dynamic processes like injection molding. Additionally, it is unknown whether the limits detected in static measurements also count for dynamic systems. In this work, a novel measurement method based on the bulk modulus of gas containing polymer melts, which provides in-line determination of dynamic solubility limits, was applied. Using a talc filled polypropylene in a MuCell®-process the question was whether the solvable amount of gas can be influenced and increased by a larger gas injection time to dosing time ratio (Rt=ti/td). Starting at a gas concentration that was initially beyond the solubility limit the ratio Rt was increased stepwise, while process pressure and gas content were kept constant. The bulk modulus method in combination with transmissive ultrasonic measurements proves that the dynamic solubility can be increased above 1.6 wt% nitrogen at 140 bar. In addition, compression work and injection work were monitored and compared to the respective states of solution. These findings show that the influence of material on solubility limits might only be relevant at long dosing and gas injection times as an equilibrium cannot develop in short times typical for injection molding. This approach is useful when large amounts of gas should be dissolved in the melt in order to achieve high density reductions. It opens new perspectives for injection foam molding. [ABSTRACT FROM AUTHOR]

Dual fuel (natural gas (NG)-diesel oil (DO)) is one of the interesting strategies that can be applied to diesel engines related to emission reduction. On the other hand its application causes a decrease in diesel engine performance. So it is necessary to look for system settings that can produce the best performance. One possible setting to analyze is the NG injection pulse width. In this study, a variation of NG injection pulse width was carried out to determine the effect on the engine performance at low to high loads. From the experimental results, it can be seen that the variation of gas injection pulse width does not significantly affect torque, power, and BMEP. There is an increase by reducing injection pulse width up to 9 ms in medium and high loads but the changes are small. Variation of injection pulse width 11 ms has the lowest SFOC and the highest thermal efficiency at medium to high loads. While the biggest substitution is obtained by injection pulse width 12 ms but at 75% load, the substitution is lower than 11 ms. [ABSTRACT FROM AUTHOR]

The progress of the improvement of dual-fuel diesel engines with diesel and natural gas fuel is quite significant. One of them implemented the split injection strategy or can also be referred to as multiple injections. This study analyzed the effects of natural gas split injection on the combustion and emission of modified dual-fuel diesel engines. The study was carried out numerically at 2000 rpm at low to high loads using proportional injection between the first injection (160°BTDC) and the second injection (100°BTDC). Moreover, natural gas substitution is maintained at 50% of the total fuel energy used. The simulation model is calibrated with the appropriate engine size. In addition, the model is validated with the results of experiments on engines with the same parameters. Results from natural gas split injection were compared with single-injection natural gas on different injection timings (160°BTDC and 100°BTDC). The results show that natural gas split injection has a significant effect on different loads. The split injection causes an increase in peak cylinder pressure and heat release rate thereby increasing torque at all loads compared to the single injection. Fuel consumption, CO, and HC in split injection mode are smaller compared to the single injection at 160°BTDC injection timing and greater than 100°BTDC at low loads up to 75% load. However, at high load is greater than all single injection. NOx split injection emissions at high load actually decrease compared to the single injection. [ABSTRACT FROM AUTHOR]

The use of Natural Gas (NG) in internal combustion engines has been increased in this decade. The objective of this paper is to investigate the NG injection timing on the dual-fuel engine. In this paper experimental based on dual fuel engine strategy (DFE strategy) was tested with several variations of gas injection based on CA at the modified direct-injection engine into a DFE strategy. In the data test, the variation is CA 260, 244, 230, 214 bTDC. This research is for observed how it affects the engine performance. The indication of the effect of NG injection based on the CA variation is the non-homogenization of the NG-air mixture in the intake manifold, and the delay in mixing NG-air to go into the combustion chamber. From several data tests that have been done, there is an increase in engine power, thermal efficiency and a decrease in SFOC fuel consumption. The optimum combination of the DFE strategy has a fluctuating value when taken from test experimental data. The trend is seen, that CA 230 bTDC is the optimum value to be operated in the DFE strategy. Because there is an increase in Torque, Efficiency thermal, and a decrease in SFOC of fuel consumption. [ABSTRACT FROM AUTHOR]

Development of marine engine technology is driven increasingly by strict emissions regulations. Dual fuel technology which uses natural gas as supporting fuel is a smart solution due to it is cleaner, cheaper and can reduces dependency on fossil fuel oil. However the phenomenon of methane slip is the biggest challenges on applications of diesel – natural gas dual fuel engine. A large amount of fuel with poor oxygen especially when engine on low load condition make some parts of methane were unburned, these uncompleted combustion raises methane slip. Meanwhile crevice or dead volume in the cylinder make gas trapped and come out as exhaust gas without participating on combustion. It is evident that being the same greenhouse gases the effect of methane slip is more dangerous than CO2 causing global warming and climate change. This research was carried out experimentally to find out how the natural gas injection time affected on the combustion performance and methane slip. On this study, three variation pulse width as injection timing of natural gas 260° BTDC, 230° BTDC and 214° BTDC were investigated to single cylinder diesel engine on constant speed 2000 rpm. The pressure of gas injection was taken fixed 3 bar, while the pilot injection timing was constant at 18 BTDC. From 30 cycles analyzed at each injection time, a significant relationship was found between optimizing the gas injection time and the gas duration to the methane slip value. Backing the injection time towards the closing of the intake valve with the right injection duration can reduce the value of methane slip. Although the 260° BTDC injection time in this research is optimal compared to the others due to the CNG wasted due to the duration of the injection that passes through the intake valve. [ABSTRACT FROM AUTHOR]

This paper concerns the description of the one-dimensional steady-state flow pattern arising from the injection of gas at supersonic velocity into a duct of uniform or diverging cross-sectional area when back pressure is applied. The considered problem is described by a boundary value problem for a singularly perturbed second order ordinary differential equation with a small parameter. But the solution of such problems is difficult, especially for small values of the parameter. Until today, there is a need to create new effective methods for solving singularly perturbed boundary value problems. The aim of the work is to find a solution to one typical aerodynamics problem. Obtained solutions will allow testing methods of numerical and asymptotic solving of this type boundary value problems. The exact solution has obtained for the constitutive equation in the case of uniform cross-sectional area. The paper found a considered problem general solution, which is divided into three independent branches. On this basis, systems of transcendental equations for finding the exact solution of the considered boundary value problem are given. The possibility of the obtained equations systems solvability and the uniqueness of the boundary value problem solution are discussed. The results obtained are in good agreement with the results of the asymptotic analysis carried out in the works of Chang, Howes, and Crocco. The form of the analytic relations confirms the possible presence of boundary and interior layers on the integral curves of the considered boundary value problem. [ABSTRACT FROM AUTHOR]

The special injection molding process GITBlow was developed by the Kunststofftechnik Paderborn and combines the processes of gas assisted injection molding (“GIT”) and blow molding (“Blow”). The parts feature large, thin-walled hollow spaces and additional functional elements. This is realized by using two consecutive gas injections and a mold with two cavities of different sizes. The first gas injection creates a hollow space within the part. In a second larger cavity the hollow space is inflated further by a second gas injection. The aim of the current research project is to manufacture hybrid structures consisting of GITBlow structures and continuous fiber-reinforced thermoplastic sheets. The new approach is to join the parts with the molten sheet material during the final phase of inflation in order to strengthen the parts locally. The parts produced with this process are characterized by their low weight, large volume and high compressive strength. To achieve the highest possible bond strength between the two components, it is necessary to maximize the temperature of the GITBlow part within the joining area. In a case study with Polycarbonate (Covesto Makolon OD 2015) and Styrene-Butadiene copolymer (Styrolution Styrolux 656C) the influence of the melt temperature and various process times on these factors can be shown. For PC a maximum temperature in the joining area of 165°C can be achieved while still maintaining optimal part quality (SBC: 120°C). Further investigations show that heat transfer within the part is of major importance for the final temperature distribution. With this knowledge an optimization of the process concerning the production of hybrid structures can be achieved. [ABSTRACT FROM AUTHOR]

Gas hydrate represents a mixture of natural gas and water molecules formed at high pressures and low temperatures near the freezing point of water. Physically, the hydrates are ice-shaped and among the water molecules, there is a cavity filled by a hydrate gas called clathrate. The hydrates can be formed because there is gas injected in water molecules at high pressure condition having temperature above the freezing point of water. Then it is exposed to a force that can dissolve gas inside the water. A lot of research has been conducted to investigate the performance of the gas hydrate itself. The performances include the rate of hydrate formation, the hydrate stability, and the hydrate storage capacity. Several studies have been studied, among others, to observe the effect of initial gas injection pressure on gas hydrate process, the effect of rotation in a vessel tank as a container for gas hydrate formation, and the hydrate formation process on stirrer tank. One of the most important things in the gas hydrate process is how the hydrate can be formed, which can be seen from the rate of hydrate formation by investigating how much the gas pressure will penetrate into water molecules. It is due the hydrate formation requires low temperature and high pressure. However, a conditioning of the gas hydrate formation at high pressure and low temperature is a matter that requires considerable energy. Therefore, it is needed a system in which the pressure of hydrate formation is not too high. One method to lower the hydrate pressure in order to the hydrate-forming pressure is not too high, CO2 will be mixed to the gas hydrate. It is because CO2 is soluble in water molecules. It make an effect that the pressure of gas formation will be lower. In the previous research, it is showed that CO2 was able to make the pressure in methane gas mixture lower. By decreasing its pressure, CO2 is expected to improve the hydrate performances. The study was conducted by varying the percentage of CO2 volume from 0% to 100%. Each percentage of CO2 will be seen as its effect on the gas hydrate performance. The gas used in this experiment were propane-butane gas mixture of 50% each. The mixture of propane-butane gas and CO2 were then fed into the water molecules. The water used was a demine water of 50 cm³. The initial pressure of the formation rate was 0.3 MPa and the temperature formation was 273 K. Meanwhile, the temperature used to stabilize the hydrate was 268 K. The vessel tank, used to process the occurrence of hydrate has the capability of high pressure has a cavity diameter material of 4 cm, height 12 cm, 0.5 cm thick and total volume of 150 cm³. The vessel tanks were inserted into the cooling bath that was set at a temperature of 273 K. The results showed that as greater the CO2 content, as smaller the initial hydrate initiation phase, However, it has an impact to decrease the hydrate stability. For hydrate storage capacity performance, pure CO2 hydrate has the highest storage capacity, while the lowest storage capacity was CO2 with gas-CO2 mixed percentage of 50%. It shows that CO2 is capable to decrease the pressure effect on 50% composition variation. [ABSTRACT FROM AUTHOR]

The mechanical properties of thin-walled plastic components are limited. One approach to improve the strength or stiffness of these components is to reinforce the thin-walled areas with an individually adapted Fused Deposition Modeling structure. Fused Deposition Modeling (FDM) is one of the most commonly used additive manufacturing processes. This process is characterized by the deposition of a fused, thermoplastic filament. Depending on the form of the reinforcement structure, the resulting hybrid structure should show higher strength or stiffness. The objective of the project is to determine constructive design and process guidelines for FDM structures. The FDM structure is to be used as a partial reinforcement for lightweight components and be adapted to the respective load conditions. Because of the lightweight application, the FDM structure should also have the lowest possible weight. The optimization of the FDM parts for different load cases is realized by adapting the design parameters. These parameters influence the layer generation and therefore also the inner structure of the FDM parts. In preliminary studies, the manufacturing restrictions of the FDM process are defined. The specimens are manufactured based on the Design of Experiments. To determine the static strength properties, different tests (tensile, compression, flexural, torsion and impact) are carried out. The investigations show that the filling strategy affects the mechanical properties. As a result of the investigations, design and process guidelines for the FDM structures are established according to the load conditions. [ABSTRACT FROM AUTHOR]

The article considers questions of ejecting devices for produced water saturation with compressed nitrogen application considering the water-alternated-gas injection technological process implementation. The WAG process effectiveness, based on the laboratory researches results and hydrodynamic simulation, was represented. In particular, displacement efficiency increase was represented. Ejector application for gazing of the water in the reservoir pressure maintenance (RPM) system is under consideration. There was simulated the ejection process in a supersonic ejector in order to define the effect of nozzle critical diameter and draft surface area on the performance parameters of the device. Control efficiency of the device ejection coefficient due to the draft surface area changing was shown. Draft surface area influence on the gas pressure value in the ejector exit is determined. Opportunity of gas ejector application for associated gas water-alternatedgas injection was represented. [ABSTRACT FROM AUTHOR]

By utilizing a pepper-pot emittance meter, we have measured the four-dimensional transverse phase-space distribution for multiply charged argon ions generated by an 18-GHz superconducting electron cyclotron resonance ion source (18-GHz SC- ECRIS) at RIKEN for gas pressures of 10-5 to 10-3 Pa during low-energy beam transport (LEBT), in order to reveal the effects of residual gas. An advantage of the presence of residual gas is neutralization and moderation of the space-charge effect of the beam. At the beam-extraction point of the SC-ECRIS, a few milliamps ion beam produces a non-negligible space-charge effect, which is expected to influence the emittance, and to depend on the LEBT pressure. To evaluate the effects of charge exchange, natural argon or hydrogen gas was injected into an LEBT system through a variable leak valve to control the amount of residual gas. In the case of argon gas injection, the charge exchange between the argon beam and the injected argon gas clearly increased when the LEBT pressure exceeded 10-4 Pa. By analyzing the four-dimensional phase-space distribution, charge-exchange components with a Bρ difference of less than 1%, which were totally inseparable using the analyzing magnet, were quantitatively estimated. After the elimination of the charge-exchange components, no significant change in the beam current or the transverse emittance was observed in the present study. Similar results were obtained for hydrogen gas injection. However, in this case, an increase was observed in the intensity of Ar-ion beams with lower charge states of 7+ and 8+, as well as multiply charged N- and O-ion beams. The injected hydrogen seemed to play a role as a "support gas", causing mixing in the ECR plasma. [ABSTRACT FROM AUTHOR]

In the computational experiment the influence of heat exchange through top and bottom of the gas-bearing reservoir on the dynamics of temperature and pressure fields during hot gas injection via a single well is investigated. The experiment was carried out within the framework of modified mathematical model of non-isothermal real gas filtration, obtained from the energy and mass conservation laws and the Darcy law. The physical and caloric equations of state together with the Newton-Riemann law of heat exchange of gas reservoir with surrounding rocks, are used as closing relations. It is shown that the influence of the heat exchange with environment on temperature field of the gas-bearing reservoir is localized in a narrow zone near its top and bottom, though the size of this zone is increased with time. [ABSTRACT FROM AUTHOR]

Pulsating combustion is among combustion control methods used to suppress formation of NOx. An upgraded automatic setup with a direct gas injection burner was used for pulsating torch studies. Experiments resulted in obtaining time series of torch area changing in longitudinal section. Singular Spectral Analysis method (SSA) upgraded to allow for choosing the size of the window was used. Spectra of the extracted components of the time series demonstrate that they contain periodic components that match the fuel supply valve on/off cycle frequency. When increasing the control frequency the spectrum of the extracted component of the time series gets broader. With further frequency increase, the spectrum approaches that of no control action and the system operates in quasi-continuous mode. The results correspond to the results obtained earlier through the spectrum analysis that confirms the phenomenon of periodic change of the torch core area in the longitudinal section under pulsating supply of fuel. [ABSTRACT FROM AUTHOR]

Results of experimental investigations on the influence of a distributed injection of a heavy gas into a nearwall sub-layer of a supersonic Mach=2 boundary layer on its laminar-turbulent transition are presented. Hot-wire measurements have been performed with two different flat-plate models, one with tangential and another one with normal (in relation to the surface) injection. It has been shown for the first time experimentally that such an injection shifts the position of transition downstream. This qualitatively confirms the obtained earlier theoretical conclusion on the stabilizing influence of heavy gas injection. The escorting linear stability computations are also presented. [ABSTRACT FROM AUTHOR]

The work is devoted to study of the formation process of nanodispersed carbon black particles during thermal decomposition of methane at high temperature (T = 1500 - 2200 K) high speed (V = 100 - 300 m/s) carrier gas flow. Using the results of numerical simulation of mixing the scheme of test gas injection through the pylon from the slot opening width of 0.1 mm and baffles is chosen. A technique of measuring Raman spectra on the test sample of nanodispersed carbon is tested. The spectra of Raman shift is obtained in the desired frequency band with the characteristic peaks in the frequency 1350 cm-1 (D-band) and 1600 cm-1 (G-band) characterizing amorphous and crystalline phase of carbon black particles, respectively. [ABSTRACT FROM AUTHOR]

Theoretical investigation of the flat-plate binary-mixture compressible boundary-layer at free-stream Mach number M=2 under the injection of heavy gas sulfur hexafluoride (SF6) has been performed. It was assumed that this foreign gas which is possible to use for wind tunnel experiments have been introduced into the boundary layer of air through the permeable surface at normal direction to it. It was found that weak distributed injection of the gas only slightly influence boundary layer streamwise velocity and temperature profiles however gives significant increase to the mixture density near the wall. Linear stability characteristics of such binary-mixture boundary-layer have been studied. It is established that action of heavy gas injection is similar to the action of wall cooling and leads to an increase of boundary-layer stability and therefore to laminar-turbulent transition delay. Estimate of the influence of injection on the position of transition by means of eN-method has been performed. Principal possibility to noticeable increase of the transition Reynolds number by means of a heavy gas injection has been established. [ABSTRACT FROM AUTHOR]

Problems of experimental modeling of the process of air blowing into turbulent boundary layer of incompressible fluid through finely perforated wall are discussed. Particular attention is paid to the analysis of both the main factors responsible for the effectiveness of blowing and the possibility of studying the factors in artificially generated turbulent boundary layer. It was shown that uniformity of the injected gas is one of the main requirements to enhance the effectiveness of this method of flow control. An example of the successful application of this technology exhibiting a significant reduction of the turbulent skin friction is provided. [ABSTRACT FROM AUTHOR]

During the past year the Spallation Neutron Source has operated with proton beam powers up to 1.4 MW with good availability. However, after a recent premature target failure the power was reduced to 1 MW for the ~20-week service cycle of the new target, whereas the subsequent target will be used at 1.2 MW. The ion source and low-energy beam transport deliver 50 to 60 mA H- beams into the RFQ with availbilities of ~99.5%. The compromised RFQ transmission limits the LINAC beam to ~35 mA, which is sufficient for 1.4 MW. Our current injector efforts focus on improving reliability and increasing the source service cycles beyond the achived 7 A·h to reduce the venting of the RFQ and to improve the stability of the accelerator operations. In addition, extraction studies show that higher extraction fields improve the RFQ transmission, apparently due to a reduced emittance of the LEBT H- beams. [ABSTRACT FROM AUTHOR]

A preliminary study of column flotation monitoring process using electrical capacitance volume tomography (ECVT) was conducted. ECVT was one of the monitoring systems which based on the capacitance measurement. It was used to understand the phenomenon that occurs inside the column in a three-dimensional (3-D) image. A linear back projection (LBP) algorithm technique was used to reconstruct the 3-D ECVT images from all measurement data obtained in this study. As a preliminary study, the effect of gas injection in the two-phase (liquid and gas) system was conducted. This study is conducted to assess the possibility of ECVT system in the monitoring of column flotation process. The experiments were conducted by using column flotation with 5 cm diameter and 150 cm height in which a sparger was installed at the bottom of column to inject air inside the column. 32-CH rectangular ECVT sensor was installed at 13 cm above the sparger and placed around the column. The gas injection variations used were 2-7 l/min with interval 1 l/min and all experiments were conducted at room temperature. Based on the signal and image analysis, the signals and 3-D ECVT images showed differences when the gas injection was varied. An increase in gas injection will decrease the fluctuation of signal intensity which correlates to the 3-D ECVT images. Average signals obtained by ECVT when given gas injection variations were in the range of 440.09 to 453.62 mV from high to low gas injection. Based on these results, ECVT has a prospect as an imaging tool to monitor the column flotation process. And also, hopefully, based on the analysis of 3-D images generated by ECVT system, the metallurgical performance would be analyzed in the further researches. [ABSTRACT FROM AUTHOR]

Intermittent gas injection is a method to help oil production process. Gas is injected through choke in surface and then gas into tubing. Gas forms three areas in tubing: gas column area, film area and slug area. Gas column is used to propel slug area until surface. A mathematical model of intermittent gas injection is developed in gas column area, film area and slug area. Model is expanding based on mass and momentum conservation. Using assume film thickness constant in tubing, model has been developed by Tasmi et. al. [14]. Model consists of 10 ordinary differential equations. In this paper, assumption of pressure in gas column is uniform. Model consist of 9 ordinary differential equations. Connection of several variables can be obtained from this model. Therefore, dynamics of all variables that affect to intermittent gas lift process can be seen from four equations. To study the behavior of variables can be analyzed numerically and mathematically. In this paper, simple mathematically analysis approach is used to study behavior of the variables. Variables that affect to intermittent gas injection are pressure in upstream valve and in gas column. Pressure in upstream valve will decrease when gas mass in valve greater than gas mass in choke. Dynamic of the pressure in the gas column will decrease and increase depending on pressure in upstream valve. [ABSTRACT FROM AUTHOR]

Carbon cluster ion beams were produced utilizing a monoplasmatoron ion source with carbon cold hollow cathodes. Changing the gas injection position of the hollow cathode caused the difference in intensities and species of extracted ions. The pure carbon cluster ion beams were successfully produced at about 36 Pa Ar gas pressure in the ion source, 70 mA discharge current, 1 kV extraction voltage and focusing by an electrostatic lens system. The source operation was often limited by discharge extinction, possibly attributable to a rapid discharge pumping. [ABSTRACT FROM AUTHOR]

Compact H+ ECR Ion Source using permanent magnets is under development. A pulsed gas injection system achieved by a fast piezo gas valve can reduce the gas load to a vacuum evacuation system. This feature is suitable when the ion source is closely located to an RFQ. Use of permanent magnets reduces the size. [ABSTRACT FROM AUTHOR]

In ASDEX Upgrade H-modes with H980.95, similar effect of the ICRF antenna loading improvement by local gas injection was observed as previously in L-modes. The antenna loading resistance Ra between and during ELMs can increase by more than 25% after a switch-over from a deuterium rate of 7.5-1021 D/s injected from a toroidally remote location to the same amount of deuterium injected close to an antenna. However, in contrast to L-mode, this effect is small in H-mode when the valve downstream w.r.t. parallel plasma flows is used. In L-mode, a non-linearity of Ra at PJCRF<30 kW is observed when using the gas valve integrated in antenna. Application of magnetic perturbations (MPs) in H-mode discharges leads to an increase of Ra>30% with no effect of spectrum and phase of MPs on Ra found so far. In the case ELMs are fully mitigated, the antenna loading is higher and steadier. In the case ELMs are not fully mitigated, the value of Ra between ELMs is increased. Looking at the W source modification for the improved loading, the local gas injection is accompanied by decreased values of tungsten (W) influx Τw from the limiters and its effective sputtering yield Yw, with the exception of the locations directly at the antenna gas valve. Application of MPs leads to increase of Τw and Yw for some of the MP phases. With nitrogen seeding in the divertor, ICRF is routinely used to avoid impurity accumulation and that despite enhanced Τw and Yw at the antenna limiters. [ABSTRACT FROM AUTHOR]

An Eulerian-Lagrangian computational model for simulations of gas-liquid flows in a continuous casting mold is developed. The flow of the fluid phase is solved in an Eulerian frame of reference together with the motion of every individually injected gas bubble, solved in its own Lagrangian frame of reference. It is assumed that the gas bubbles remain spherical and their shape variations are neglected. In order to consider the bidirectional interactions between the bubbles and the melt flow two different methods (the one-way coupling and the two-way coupling) are studied and compared. The simulations show that the two-way coupling is essential to get realistic results. [ABSTRACT FROM AUTHOR]

Based on Euler-Euler approach, a mathematical model is established to describe gas and liquid two-phase flow in a gas injected mechanically stirred system used in hot metal desulfurization process. The influences of different impellers types and rotation methods were investigated. The results show that the predicted distribution of bubbles in the bath agrees well with experimental results. The gas-liquid flow in the gas injected-mechanically stirred system can be accurately described by the present model. Compared to the standard impeller, the improved impeller in forward stirring mode is more efficient to increase the retention time and dispersion of bubbles. [ABSTRACT FROM AUTHOR]