Pressurized Hydraulic Fluid Research Articles

Optimization of subsea production control system layout considering hydraulic fluid pressure loss

Historically, layout optimization of the Subsea Production Control System (SPCS) has primarily emphasized equipment construction costs, frequently overlooking the influence of the seabed's three-dimensional terrain on hydraulic pressure loss during power distribution. Such neglect can escalate maintenance costs throughout the oil and gas field's lifespan. This article presents an advanced SPCS layout optimization approach that addresses hydraulic pressure loss. A multi-objective optimization model, accounting for the intricate seabed three-dimensional terrain and obstacles, was developed for the multi-level Star-Tree structured SPCS. This model integrates parameters such as construction costs, pressure loss, and pipeline routes. By merging the strengths of NSGA-II (Non-dominated Sorting Genetic Algorithm II) and Lazy Theta*, a novel hybrid algorithm has been proposed. This algorithm is adapted at determining the optimal position for the Subsea Distribution Unit (SDU), refining the pipeline connectivity topology, and minimizing pressure loss, thereby identifying superior laying paths. In a case study featuring an SPCS with 20 Subsea Control Modules (SCM) and one Floating Production Storage and Offloading (FPSO) unit, the method's efficacy in reducing hydraulic pressure loss was demonstrated in simulation results. The findings of this research hold promise as a pivotal decision-making instrument during the SPCS design phase, providing profound theoretical insights for layout design.

Design and Numerical Simulation-Based Optimization of a Novel Flat-Face Coupling System for Hydraulic Power Equipment

Coupling systems play a vital role in hydraulic power transmission equipment. In recent years, flat-face coupling systems have been extensively studied due to their environment friendly features. The difficulty of the connection process of hydraulic equipment increases with the increase in their working pressure. To improve the convenience of making high-pressure connections, a novel flat-face coupling system is proposed in this article. In the proposed design, which is based on the conventional flat-face coupling system, the resistance caused by high hydraulic fluid pressure during coupling is drastically reduced by the addition of an instantaneous pressure relief module. In this study, the theoretical model of the system kinetics is established to illustrate the operational mechanism of the novel design, and a series of computational fluid dynamics numerical investigations based on the novel dynamic mesh technology and Ansys Mosaic meshing technology are implemented to verify the rationality of the proposed design. Additionally, an optimal design of the novel flat-face coupling system is proposed to reduce the energy loss during hydraulic power transmission.

Hydrostatic cyclic extrusion compression (HCEC) process; a new CEC counterpart for processing long ultrafine-grained metals

Hydrostatic cyclic extrusion–compression as a novel severe plastic deformation method in the processing of the rods is introduced and used for refining ultrafine-grained commercial pure aluminum. HCEC is solving the limitation of the conventional CEC in producing long-length samples by utilizing pressurized hydraulic fluid and eliminating the frictional effects. An increase in the length of the processable sample, a reduction in the processing loads, an intensification in the hydrostatic stress, and improvement in the strain distribution are the novel achievements of the HCEC. The capability of HCEC in grain refinement of the commercial pure aluminum was investigated by transmission electron microscopy analysis. The processed samples showed the grain sizes of 780 nm and 400 nm after the first and second passes of the HCEC, respectively. Furthermore, tensile and shear punch tests were utilized for investigation of the mechanical properties of the unprocessed and HCEC processed rods. An increase in the tensile and shear yield and ultimate strengths after the process confirmed the decreases in grain sizes. The tensile yield and ultimate strengths of the rod after the second cycle of the process reached 170 and 196 MPa, respectively. The same increasing trend as strength was shown in the microhardness after the HCEC. FEM analysis depicted the homogenous distribution of strain along the length of the sample. Also, the independency of the processing force to the length of the sample was shown by the FEM. The implementation of this novel technique looks very interesting for the industrial utilization of SPD techniques, especially in automotive and aerospace industries, which suffer from the limited size of the processing specimens.

Experimental investigations of fracturing fluid flowback and retention under forced imbibition in fossil hydrogen energy development of tight oil based on nuclear magnetic resonance

Experimental works have proved that imbibition under forced pressure (FP, the difference between hydraulic fluid pressure and original pore pressure) has a positive effect on fossil hydrogen energy development in tight oil reservoir. However, the knowledge of the influence of imbibition under forced pressure (forced imbibition, FI) on fracturing fluid flowback and water retention is still limited. In this paper, experiments were designed and conducted to reveal the mechanism of fracturing fluid flowback and water retention under imbibition effect in tight sandstones. As a comparison, unconsolidated sandstones were also investigated in this study. Core samples were divided into two categories: the imbibition ones (treated by imbibition) and the filtration ones (treated by displacement), in accordance with the real oil-water distribution after well shut-in. An imbibition core and a filtration core were stitched together to conduct a flowback experiment. During the experiment, fluid distribution in different pore sizes was monitored continuously by using a low-field nuclear magnetic resonance device. Results show that the flowback recovery in tight sandstones is much lower than that in unconsolidated sandstones due to the difference of pore structure. Meanwhile, forced imbibition leads to higher oil recovery than spontaneous imbibition (SI) in tight sandstones since forced pressure enhances water imbibition. The water imbibed into small-macro and macro pores contributes the major flowback recovery, but the imbibed water in micro pores is rather difficult to displace and finally retains in these pores during the flowback process. Overall, forced imbibition not only enhances oil recovery but also increases water retention, explaining the mechanism of well productivity increase by using the shut-in method in the field. This study can help to clarify the influence of forced imbibition on fracturing fluid flowback and enhancement of fossil hydrogen development, and further provide guidance for flowback designs.

Investigation of Deformation Induced Micro to Macro scale Surface Roughness

In the present work the relationship between deformation and deformation induced surface roughness of 100 micron thick annealed AISI 304 stainless steel was investigated at the meso scale. This work is a continuation of the previous work by the authors where roughness values were determined at the apex of the bulge test samples at micro scale. The apex is believed to be the region of highest stress and strain in a typical bulge process in a circular die. The material was deformed using a biaxial bulge test through hydraulic fluid pressure. The strains on the workpieces were measured with respect to the forming pressure. The surface roughness was measured by scanning the interior (concave) area of bulge with Bruker GTK-17 optical profilometer over an area of 1.3mm x 1mm. The results show linear relationship between roughness and deformation strain, and it establish a similar trend with roughness measured at micro scale.

Microstructure and Mechanical Properties of the Commercially Pure Copper Tube After Processing by Hydrostatic Tube Cyclic Expansion Extrusion (HTCEE)

A newly introduced severe plastic deformation process for the production of relatively long ultrafine-grained (UFG) tubes, hydrostatic tube cyclic expansion extrusion (HTCEE), was applied up to two passes on commercially pure copper tubes to study the mechanical characteristics and microstructure of the HTCEE processed samples. In HTCEE process, the pressurized hydraulic fluid around the piece has a main role in the reduction of the friction load leading to a decrease in the required pressing force. After the second pass of HTCEE, a UFG microstructure with an average grain size of ~ 127 nm was observed. In two-pass HTCEE processed tub, more refined and also more homogeneous microstructure was achieved compared to the one-pass HTCEE processed and annealed samples. This type of microstructure caused the increment of yield strength from 75 to 310 MPa, (~ 4.13 times higher), ultimate tensile strength from 207 to 386 MPa (~ 1.86 times higher) and microhardness from ~ 59 to ~ 143 Hv (~ 2.42 times higher). Simultaneously, elongation to failure was lessened from ~ 55 to 37%. In other words, a remarkable increase in the strength and hardness was attained besides a low loss of ductility. Also, microhardness measurements revealed a more homogeneous distribution of hardness in the two-pass processed sample. SEM fractography analysis demonstrated that mostly ductile fracture happened in the HTCEE processed samples. Also, the influence of the HTCEE process on the equivalent plastic strain and also the required force was examined via FEM simulation using Abaqus software. It seems that HTCEE process, by applying low deforming force, possesses the potential of production of tubes with long length having a simultaneous good ductility and strength.

Experimental and analytical evaluation of Incremental Sheet Hydro-Forming strategies to produce high forming angle sheets

Incremental Sheet Hydro-Forming (ISHF) is a hybrid process of Incremental Sheet Forming (ISF) and Sheet Hydro-Forming (SHF). In the ISHF process, a single ball tool moves over one side of the surface of the sheet and hydraulic support is provided in another by using the pressurized hydraulic fluid. In the current research, an attempt has been made to achieve high forming angles using ISHF. The forming strategy, multi-stage & multi-step (MSMS), has been proposed to improve the formability in ISHF. The MSMS has resulted in the improvement in the formability and forming angle achieved is 78.75o. The primary issue, identified in MSMS forming strategy, is the failure of the product due to thinning of the sheet. To address the failure of the sheet due to thinning, a modified version of MSMS was proposed. This modified version of MSMS has shown tremendous improvement in the formability of the ISHF. The forming angle upto 90o has been successfully achieved using the modified version of MSMS. Analytical models have been developed for MSMS forming strategy and for the modified version of MSMS forming strategy. The experimental results are closely the same as predicted by analytical models.

Experimental process pressure analysis for model-based manufacturing of composites by resin transfer moulding

An experimental study of the process pressure characteristics prevailing in an RTM mould during the preform impregnation stage is presented. The pressure data is analysed with respect to a superposition of preform compaction and hydraulic fluid pressure. A methodology is proposed to isolate the hydraulic fluid pressure from the preform compaction pressure involving knowledge about the compressibility behaviour of the reinforcing material. For this purpose, the preform compressibility and relaxation behavior was studied by means of transverse compaction tests on both, unsaturated as well as the saturated sample stacks. The resulting isolated hydraulic fluid pressure is finally compared with numerical predictions derived from flow simulations, revealing good overall agreement. The findings of this work will contribute to realize the concept of model-based processing of fibre-reinforced polymer composites by means of the RTM process.

Thermal analysis of hydraulic system of landing gear

Landing gear of any aircraft is an important system which aids in takeoff, landing and supports the aircraft on runway. Landing gear system employs a hydraulic actuation system for its operation. Hydraulic system provides pressurized hydraulic fluid for actuation of main and nose landing gear in deployment/retraction mode and brake pressure for braking. Advantage of Hydraulics is small sized actuators due to its high power density, easy control and transmission of power. Hence hydraulics always had been a preferred choice for compact high power systems. During the energy conversion, fluid transmission losses and inherent friction, heat energy is generated in the system which rises the fluid temperature. This heat has to be dissipated by proper means to maintain the system temperature within safe limits. This paper attempts to study the thermal aspects of hydraulic system, heat generation and dissipation to estimate temperature rise profile and steady state temperature.

INDIRECT MEASUREMENT METHODOLOGY OF CARGO WEIGHT LIFTED BY THE EXCAVATOR IN THE CRANE MODE

Introduction.To solve the indirect measurement problem of the cargo weight lifted by the excavator in crane mode the authors propose the specific method and develop mathematical model according to the indications of hydraulic fluid pressure sensors in the piston and rod cavities of boom lifting cylinders. Moreover, the signals from the angle sensor of the boom and the handle relative to the gravity horizon are used, the roll and pitch sensors of the rotary column of the excavator relative to the gravity horizon are additionally applied.Materials and methods. As initial data of the indirect measurement method of cargo mass, constant design parameters, constant masses of moving links are used, such as booms with handle hydraulic cylinder, handles with bucket hydraulic cylinder and bucket turning mechanism, bucket weight. In addition, constant linear number and angular machine dimensions are included in the investigation. To obtain analytical formulas of the method, the method of homogeneous coordinates is applied, as well as the method of direct analytical inference.Results.The developed design scheme of the method is presented. As a result, the position of the excavator crane is described in the right-hand rectangular coordinate system. Moreover, the technique of indirect measurement of cargo mass according to the indications of hydraulic fluid pressure sensors in the form of formulae linear sequence is presented.Discussion and conclusion. The accuracy of the developed method was estimated by comparison with the results of the full-scale experiment. The relative reduced measurement error in the range of boom angles’ measurement and the crane-excavator handle was less than ten percent. Therefore, the technique merits are its simplicity, as well as record of the roll and pitch angles of the crane-excavator turntable element.

Characteristics and Influencing Factors for Forced Imbibition in Tight Sandstone Based on Low-Field Nuclear Magnetic Resonance Measurements

Spontaneous imbibition (SI) generally occurs under forced pressure (the difference between hydraulic fluid pressure and original pore pressure) during shut-in time. However, the experimental study of SI is commonly performed at atmospheric pressure and the effect of the forced pressure is often neglected. How the forced pressure influences the SI behaviors under different factors is still not clear. In this paper, low-field nuclear magnetic resonance (LF-NMR) was adopted to study the mechanism of SI in the tight sandstone rock sample under forced pressure (forced imbibition, FI). The effects of boundary conditions, initial water saturation, bedding plane (BP) direction, and fluid salinity on oil recovery were also systematically investigated. Results showed that the ultimate oil recovery (UOR) varied from different boundary conditions. An inverse correlation also exists between the water uptake and salinity. As osmotic pressure exists, more water was imbibed into core samples with the decrease of KCl sali...

Hydrostatic cyclic expansion extrusion (HCEE) as a novel severe plastic deformation process for producing long nanostructured metals

In this paper, hydrostatic cyclic expansion extrusion (HCEE) is developed as a new severe plastic deformation technique for processing of the relatively longer ultrafine grained samples. Increasing the length of the processed sample, decreasing the processing load astonishingly, and increasing the hydrostatic stresses are the main advantages of HCEE. In this process, pressurized hydraulic fluid surrounded workplace played the primary role in reducing the friction load and in reducing consequently total load. The HCEE process was applied to commercial pure aluminum 1050 samples at room temperature, and then microstructural evolution and mechanical properties were examined. Microstructure analysis using back-scatter diffraction (EBSD) revealed that a significant grain refinement is achieved after the HCEE process. The average size of grains and subgrains decreased to ~700 nm after two passes of the HCEE process from the initial value of 50 µm in the unprocessed sample. Yield and ultimate strength were increased from 40 MPa and 52MPa to 125 and 137 MPa after two passes of HCEE process. Also, microhardness was increased from 36 HV to 45 HV after the first pass. The process seems to be very promising for industrial application of SPD processing which suffer from the main challenge of limited sample size.

The Experimental Investigation of Springback in V-Bending Using the Flexforming Process

The flexforming process is a sheet metal forming method that uses hydraulic fluid pressure and a rubber diagram to form sheet metal with a die. This study, for the first time, experimentally investigates the factors affecting the springback resulting from the bending of copper and brass sheet metal materials in V-bending dies using the flexforming process. Additionally, the formability during the V-bending method was experimentally investigated by using thin, high-pressure-resistant rubber membranes instead of the thick ones commonly used in the flexforming processes. The process parameters in the experimental studies were determined to be: holding time (0, 5 and 10 s), bending angle (\(15^{\circ }, 30^{\circ }, 45^{\circ }, 60^{\circ }, 75^{\circ }\) and \(90^{\circ })\) and fluid pressure (10, 12 and 14.4 MPa). Sheet metals were formed in V-bending dies by both flexforming and conventional bending processes to compare the performance of the flexforming process against the conventional bending process. Springback values in the parts formed using the flexforming process for copper and brass sheet metals were determined to be 39.06 and 41.42% less, respectively, than those formed by the conventional bending method. Surface flaws occurring in the parts formed by the conventional bending method were not observed in the parts formed using the flexforming process. The springback was also estimated by using fuzzy logic based on unexecuted break-test parameters. When the outputs of the fuzzy logic system were compared with the experimental results, it was observed that the results were substantially similar.

Transient modeling of a gas-liquid piston-cylinder mechanism for low temperature energy conversion applications

Transient modeling of a novel piston-cylinder gas-to-liquid energy conversion mechanism is performed in order to estimate the isentropic efficiency and contribution of various losses to the total energy transfer of the mechanism. A case study is performed to comparatively evaluate the contributions of losses. The cumulative efficiency of one cycle corresponds to 82.1% by considering heat transfer, clearance volume, friction, and valve losses. The energy of pressurized hydraulic fluid with high head can be used in high efficient hydraulic turbines, such as Pelton and Francis with efficiencies up to 93%, to produce electrical energy. The selection of these types of hydraulic machines lies under the motivation of having such a low volumetric flow rate and higher head pressures. The present integrated system efficiency offers promising results for power production from low-temperature thermal resources.

Onions can Bend, Contract and Elongate just Like Muscles

Bioinspiration or biomimetics is a field which deals with the study of the structure and function of biological systems for the designing and fabrication of materials, devices and machines. Bio mimetics can offer new potential for designing devices with novel abilities by simply replicating nature or natural phenomena. An actuator is a kind of motor which is responsible for moving or controlling a definite mechanism or system. It can be operated by any energy source, typically electric current, hydraulic fluid pressure or pneumatic pressure and converts that energy into motion.

Radial deformations of working cylinder of hydraulic Legs depending on their extension

Current methods of calculation of parameters of hydraulic legs of powered supports are in most cases analytical and do not consider all complex of factors. Finite element model was developed to study this problem and used to analyze the influence of hydraulic legs extension on radial deformations of cylinder of different producers of powered supports at variation of hydraulic fluid pressure. It was revealed that radial deformations of cylinders along the axis of hydraulic legs increase in magnitude in direct proportion to the hydraulic fluid pressure and extension. Research results can be recommended to define optimal geometric parameters of hydraulic legs in respect to the minimal radial deformations of hydraulic cylinder increasing its impermeability and improving the work of cup seals. It is recommended to use the obtained results at power support designing.

Failure of an Aero Engine Ball Bearing Due to Axial Loading

During a flight of an aircraft, the rpm of one engine dropped to 96% with frequency 390 cycles per second (CPS). The pilot tried to stabilize the rpm of the engine using standard procedures but failed and soon the rpm further dropped to 95%. The engine was switched off and a safe landing was made with remaining three engines. During initial investigation, cage of one of the rear bearing of governor in the valve housing was found broken, whereas second bearing of this set was found unserviceable due to abnormal play. Valve housing was a part of propeller control assembly. It controls flow of pressurized hydraulic fluid toward pitch changing mechanism in the dome assembly through cams, valves, and switches, to change the propeller blades angle. The ball bearing under consideration was supposed to run for indefinitely long period it was to be replaced mandatorily during overhaul of the valve housing after 6000 h of its life. In this particular case, failed ball bearing had consumed only 1938.4 h. The failure analysis of the bearing was carried out, and the factors found to be contributing in the failure of bearing were (a) Improper mounting and/or excessive axial load, (b) Entrapment of the foreign particles leading to wear and stresses at localized regions, (c) Contact fatigue under excessive axial loads leading to formation of spalling; the formation of debris during spalling might also enhance the wear.

Feasibility of a Hydraulic Power Assist System for Use in Hybrid Neuroprostheses.

Feasibility of using pressurized hydraulic fluid as a source of on-demand assistive power for hybrid neuroprosthesis combining exoskeleton with functional neuromuscular stimulation was explored. Hydraulic systems were selected as an alternative to electric motors for their high torque/mass ratio and ability to be located proximally on the exoskeleton and distribute power distally to assist in moving the joints. The power assist system (PAS) was designed and constructed using off-the-shelf components to test the feasibility of using high pressure fluid from an accumulator to provide assistive torque to an exoskeletal hip joint. The PAS was able to provide 21 Nm of assistive torque at an input pressure of 3171 kPa with a response time of 93 ms resulting in 32° of hip flexion in an able-bodied test. The torque output was independent of initial position of the joint and was linearly related to pressure. Thus, accumulator pressure can be specified to provide assistive torque as needed in exoskeletal devices for walking or stair climbing beyond those possible either volitionally or with electrical stimulation alone.

합성 윤활유 및 고압 작동유 누출감지 필름형 센서의 구현

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

Possible Alternatives for Deep-Water Gas Charged Accumulators

Gas Charged Accumulators are widely used in Drilling operations; however, the current Accumulator design methods are inadequate for Deepwater Drilling. Gas-Charged Accumulators are used in subsea drilling as well as production operations. One important application of accumulators is in blowout preventers (BOPs). BOP’s are designed to shut in a well under pressure so that the well control procedures could be implemented. Control Systems for the BOPs should be highly efficient hydraulic systems and operate in as short a time as possible. Supplying enough volume of pressured hydraulic fluid to operate those emergency functions is essential. To have the necessary quantity of control fluid under pressure requires storing this fluid in accumulators. Gas Charged Accumulators are the most commonly used accumulators in Drilling operations. These accumulators are not efficient at all in Deep waters, and there are not many alternatives for them. This paper looks into possible alternatives for Gas Charged Accumulators in Deep Waters. Supplying enough volume of pressurized hydraulic fluid to operate the BOPs for emergency situations is essential for Deep Water Drilling. This requires storing the pressurized hydraulic fluid in accumulators. A problem may arise when the wellhead is at water depth of more than 3500 ft. In deep water drilling, the accumulators should be placed on the subsea BOP stack to reduce hydraulic response times and provide a hydraulic power supply in case of interruption of surface communication. Hydraulic fluid capacity of an accumulator may drop to 15% of its capacity on the surface and even less, depending on the water depth. The reason for this is that the nitrogen gas does not behave like an ideal gas as we go to very deep water, due to high hydrostatic pressure at that water depth. We have to look for alternatives to Gas Charged Accumulators. It has to be something that is able to store energy, but unlike the nitrogen, its functionality should not be affected by the increasing hydrostatic pressure of water. The possibility of the use of springs and heavy weights as possible replacements for nitrogen in structure of accumulators will be discussed in this paper. High hydrostatic pressure of deepwater should not affect the functionality of these mechanical accumulators. Transferring bank of accumulators to the surface and connecting them to the BOP with properly sized and rigid pipes can decrease response time to an acceptable extent to satisfy regulations and standards. This idea can be considered as an alternative solution too. We have to include the hydrostatic pressure of water in the usable fluid calculation. A low pressure tank located on the sea-floor can dismiss the negative effect of high hydrostatic pressure of seawater. This alternative idea is also discussed. Efficient deep water accumulators would reduce the number of accumulators required in deepwater and cut the cost of the project. With the advent of such efficient accumulators, we can hope that one of the numerous problems of deepwater drilling has been solved and we can think of drilling in even deeper waters. Key words : Drilling operations; Deep-water gas charged accumulators; BOPs