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This paper aims to explore the influence of CO₂ partial pressure, flow rate and water cut on N80 steel corrosion behaviors in the displacement process of oil in glutenite reservoir by CO₂ injection.

A self-made 3 L high-temperature and high-pressure autoclave was used to conduct corrosion simulation experiments of N80 steel in different CO₂ partial pressures, flow rates and water cut (the independently developed oil and water mixing approach can ensure the uniform mixing of oil and water in experiments). Techniques like weight loss and surface analysis were used to analyze the corrosion behaviors of N80 steel under different conditions.

Results showed that the average corrosion rate of N80 steel accelerated at varying degrees with the increase of CO₂ partial pressure, flow rate and water cut. Excluding that the samples showed uniform corrosion under the two conditions of 0.5MPa CO₂ partial pressure and static corrosion, they displayed mesa attack corrosion under other conditions. Besides, with the increase of CO₂ partial pressure, the pH value of solution dropped and the matrix corrosion speed rose, hence leading to the increased Fe²⁺ and CO₃²⁻ concentration. Meanwhile, a lowered pH value improved the FeCO₃ critical supersaturation, thereby leading to an increased nucleation rate/growth rate and ultimately causing the decrease of the dimension of FeCO₃ crystallites formed on the surface of the samples.

The results can be helpful in targeted anti-corrosion measures for CO₂/oil/water corrosive environment.

The purpose of this paper is to study the influence of structural parameters of oil groove (such as central angle number, depth and so on) on pressure, flow, load capacity and transmitted torque between friction pairs of hydro-viscous clutch.

According to the working process of friction pairs of hydro-viscous clutch, mathematical models of hydrodynamic load capacity and torque transmitted by the oil film were built based on viscosity-temperature property. Then analytical solutions of pressure, flow, load capacity and transmitted torque were obtained; effects of central angle of oil groove zone and friction contact zone, oil film thickness, number of oil grooves on pressure, flow, load capacity and torque were studied theoretically.

The research found that the central angle of oil groove zone, number of oil grooves and oil groove depth have similar effects on flow, which means that with the increase of central angle, number or depth of oil grooves, the flow also increases; pressure in friction contact zone and oil groove zone drops along radial direction, whereas its value in oil groove zone is higher. With the increase of the central angle of oil groove zone, pressure in friction contact zone and friction contact zone rises, and the load capacity increases, whereas the transmitted torque drops. Number of oil grooves has little effect on load capacity. When the oil film thickness increases, its flow increases accordingly, whereas the pressure, load capacity and transmitted torque drops. Meanwhile, the transmitted torque decreases with the increase of number of oil grooves, whereas the oil groove depth nearly has no effects on transmitted torque.

In this paper, mathematical models of hydrodynamic load capacity and torque transmitted by oil film were built based on viscosity-temperature property in the working process of hydro-viscous clutch, and their analytical solutions were obtained; effects of structural parameters of oil groove on transmission characteristics of hydro-viscous clutch based on viscosity-temperature property were revealed. The research results are of great value to the theory development of hydro-viscous drive technology, the design of high-power hydro-viscous clutch and relative control strategy.

The purpose of this paper is to investigate the hydrodynamic performance of a single‐screw extruder with special reference to metering region.

The hydrodynamic analysis of a single screw extruder is carried out by dimensional and non‐dimensional parameters defining the polymer flow behaviour. The flow types formed in the extruder channel are defined and the relationship between the flow with the extruder geometry is examined.

The theoretical model developed is capable of estimating the hydrodynamic behaviour of extruder metering region. With the model developed, extruder geometry and polymer flow rate under different operating conditions can be predicted.

This paper offers a quick and easy opportunity to examine the hydrodynamic behaviour of extruder metering region. With the theoretical model developed, the behaviour of the flow in extruder can be modelled and estimated.

This paper aims to increase the knowledge of the run-in process of lubricated contacts in hydraulical pumps. When performing EHL simulations of tribological contacts, the surface influence needs to be taken into account. This experimental measurement wants to investigate the amount of change of the flow factors in the first hour of run of tribological contacts.

An experimental test bench is used to run-in several samples. After several minutes of running, samples are removed and the surface structure is captured using a digital microscope. With the measured data, flow factors are calculated.

The findings were clear that flow factors are highly direction-dependent, especially shear flow factors in radial directions experience almost no change. Overall, influence of the surface structure of up to 30% compared to a flat surface can be registered.

This paper helps to choose application-oriented values for the simulation of tribological contacts.

This paper aims to investigate analytically the air bearing pressure and film spacing of the linear head/tape interface by numerical iterations between the one‐dimensional compressible Reynolds and Bernoulli tape equations.

In order to account for the molecular rarefaction effect of the ultra‐thin gas lubrication, the pressure flow rate with three optimal adjustable coefficients was implemented into the steady state Reynolds equation. Using the central finite difference approach, the two coupled nonlinear equations can be discretized and numerically solved. To speed up the convergence of the tape position to be obtained, a fictitious stiffness was implied during the process.

By comparison with the Talke's first order model, the differences are significant and cannot be neglected. A smaller film spacing of head/tape can be acquired by a lower tape speed or a higher tape tension, while the slot edge defect and stain will effectively lower the built‐up pressure, thus decreasing the recording density and data access efficiency.

Incorporating the high‐order slip‐flow model into the modified Reynolds equation and coupled with the Bernoulli tape deflection equation, this study proposes a feasible approach to the analysis of molecular rarefaction effect on head/tape interface in a linear tape drive.

Traditionally the development process has been used to optimise engine lubrication systems with a lot of hardware testing. This can lead to an expensive and time consuming process which can have major influences on the engine design. To complement engine development, design and analysis principles have been developed for further optimisation and understanding of the lubrication system. To demonstrate this a case study is used illustrating good use of analysis tools, offering clear ways towards system optimisation. In addition, while engine designers have been improving their techniques, new components and oil formulations have helped push the boundaries of the lubrication system, giving better wear and friction characteristics and also increasing oil life.

This paper aims to analyze spray characteristics of rapeseed oil as a cutting fluid in minimum quantity lubrication (MQL) through numerical simulation.

Computational fluid dynamics (CFD) is used in this numerical study. The Eulerian–Lagrangian approach was used in this simulation to project trajectories of the droplets as the cutting fluid is dispersed into a continuous phase, i.e. air. The spray characteristics of the multiphase fluids were obtained numerically using the discrete phase model (DPM).

The spray characteristics such as particle diameter and velocity were obtained for various pressure level, flow rate and nozzle diameter. The particle diameter decreased with increased pressure, whereas the velocity increased with increased pressure, flow rate and nozzle diameter. The changes in particle diameter are insignificant with respect to flow rate and nozzle diameter. DPM is an effective tool for machining processes to determine the behaviour of different cutting fluids under the MQL system.

In this study, the droplet and velocity distribution of vegetable oil, i.e. rapeseed oil, was investigated at the different air pressure, flow rate and nozzle diameter. This study will give insight for the manufacturer to select the better MQL system parameters to reduce the cost, time of machining processes and enhance the sustainability of the process.

The purpose of this paper is to propose a new simplified numerical model, based on a very compact semi-empirical formulation, able to simulate the fluid dynamics behaviors of an electrohydraulic servovalve taking into account several effects due to valve geometry (e.g. flow leakage between spool and sleeve) and operating conditions (e.g. variable supply pressure or water hammer).

The proposed model simulates the valve performance through a simplified representation, deriving from the linearized approach based on pressure and flow gains, but able to evaluate the mutual interaction between boundary conditions, pressure saturation and leak assessment. Its performance was evaluated comparing with other fluid dynamics numerical models (a detailed physics-based high-fidelity one and other simplified models available in the literature).

Although still showing some limitations attributable to its simplified formulation, the proposed model overcomes several deficiencies typical of the most common fluid dynamic models available in the literature, describing the water hammer and the nonlinear dependence of the delivery differential pressure with the spool displacement.

Although still based on a simplified formulation with reduced computational costs, the proposed model introduces a new nonlinear approach that, approximating with suitable precision the pressure-flow fluid dynamic characteristic of a servovalve, overcomes the shortcomings typical of such models.

The purpose of this study is to design a closed hydrostatic guideway has the ability to resist large-side load, pitch moments and yaw moments, has good stiffness and damping characteristics, and provides certain beneficial guidance for the design of large-span closed hydrostatic guideway on the basis of providing a large vertical load bearing capacity.

The Reynolds’ equation and flow continuity equation are solved simultaneously by the finite difference method, and the perturbation method and the finite disturbance method is used for calculating the dynamic characteristics. The static and dynamic characteristics, including recess pressure, flow of lubricating oil, carrying capacity, pitch moment, yaw moment, dynamic stiffness and damping, are comprehensively analyzed.

The designed closed hydrostatic guideway has the ability to resist large lateral load, pitch moment and yaw moment and has good stiffness and damping characteristics, on the basis of being able to provide large vertical carrying capacity, which can meet the application requirements of heavy two-plate injection molding machine (TPIMM).

This paper researches static and dynamic characteristics of a large-span six-slider closed hydrostatic guideway used in heavy TPIMM, emphatically considering pitch moment and yaw moment. Some useful guidance is given for the design of large-span closed hydrostatic guideway.

The contact and lubrication performances, which were previously estimated assuming a Gaussian surface, are insufficient due to the non-Gaussian surface characteristics of the honing liner. The purpose of this study is to analyze the liner honing surface and examine its effects on the contact and flow performance.

The fast Fourier transform (FFT) method was used to generate the liner honing texture. Subsequently, an elastoplastic contact model based on boundary element theory was constructed and simulated for the honing surface. The results were compared with those obtained using a Gaussian surface. In addition, flow factors of the honing surfaces were also compared.

The contact pressure and flow factors demonstrate significant disparities when dealing with non-Gaussian surfaces. In the deterministic model, the pressure exhibits considerably diminished magnitudes and a more evenly distribution. Moreover, when the gap between surfaces is narrow, the discrepancy in flow factor across different directions on the real honing surface becomes more prominent compared with the Gaussian surface.

The model incorporates the influence of the non-Gaussian honing surface, thereby enabling more accurate prediction.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0198/