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A domain‐adaptive technique which maps the unknown, time‐dependent, curvilinear geometry of annular liquid jets into a unit square is used to determine the steady state mass absorption rate and the collapse of annular liquid jets as functions of the Froude, Peclet and Weber numbers, nozzle exit angle, initial pressure and temperature of the gas enclosed by the liquid, gas concentration at the nozzle exit, ratio of solubilities at the inner and outer interfaces of the annular jet, pressure of the gas surrounding the liquid, and annular jet's thickness‐to‐radius ratio at the nozzle exit. The domain‐adaptive technique yields a system of non‐linearly coupled integrodifferential equations for the fluid dynamics of and the gas concentration in the annular jet, and an ordinary differential equation for the time‐dependent convergence length. An iterative, block‐bidiagonal technique is used to solve the fluid dynamics equations, while the gas concentration equation is solved by means of a line Gauss‐Seidel method. It is shown that the jet's collapse rate increases as the Weber number, nozzle exit angle, temperature of the gas enclosed by the annular jet, and pressure of the gas surrounding the jet are increased, but decreases as the Froude and Peclet numbers and annular jet's thickness‐to‐radius ratio at the nozzle exit are increased. It is also shown that, if the product of the inner‐to‐outer surface solubility ratio and the initial pressure ratio is smaller than one, mass is absorbed at the outer surface of the annular jet, and the mass and volume of the gas enclosed by the jet increase with time.

A hybrid bearing of advanced cryogenic rocket engine turbopump is designed. For cryogenic fluid propellants (such as liquid oxygen) as the lubrication of bearing, bearings operating close to liquid-vapor region (near the critical point or slightly sub-cooled) are likely to develop a two phase flow region. The paper aims to discuss these issues.

In this paper, an all liquid, liquid-vapor mixture, and all vapor, i.e. a continuous vaporization bulk flow model of density and viscosity for mixture fluid, is presented, and the general Reynolds equation and energy equation with two phase flow as lubricants is solved. The static and dynamic performance of a 50-mm-radius hybrid bearing are obtained under 20,000 rpm speed and 10 MPa supply pressure.

The results show that the variations of performance of bearing operating under cryogenic liquid oxygen are not bounded by the all liquid and all vapor cases in the liquid-vapor mixture range. There behaviours are attributed to the large change in the compressibility character of the flow.

For validating the correctness of analytical model, an experimental study on the liquid-vapor nitrogen mixture lubricated hybrid journal bearings is being carried out where low-viscosity nitrogen was selected as the lubricant for the sake of safety. Soon after, the authors will discuss the results and publish them in the new papers.

An all liquid, liquid-vapor mixture, and all vapor, i.e. a continuous vaporization bulk flow model of density and viscosity for mixture fluid, is presented. The static and dynamic performance of hybrid bearings with two phase flow as lubricants are obtained.

The purpose of this paper is to synthesize a novel kind of crown‐type phosphate ionic liquids with better tribological properties for steel/Al system. The anions of crown‐type phosphate ionic liquids contain no F element, which are non‐corrosive to metal.

To improve the tribological properties of ionic liquid lubricants for the extremely difficult system of the steel‐against‐aluminum metal couple, novel crown‐type phosphate ionic liquids were prepared. The tribological properties of the crown‐type phosphate ionic liquids were evaluated at different loads and frequencies on an Optical SRV oscillating friction and wear tester. The morphology and chemical compounds of the wear scars were investigated by scanning electron microscope (SEM) and X‐ray photoelectron spectroscopy (XPS).

Compared with conventional ionic liquids, the novel crown‐type phosphate ionic liquids prepared in the present work exhibit a more excellent anti‐wear ability for steel/Al2024 contact at different loads and frequencies. By the morphological analysis with SEM, less debris was observed in the worn surface lubricated with crown‐type phosphate ionic liquids, though more debris was observed when lubricated with LB106 and LP106. By the XPS analysis, boundary lubrication film composed of aluminum (III) oxide, organometallic compounds, and silicon aluminum phosphate were found in the worn surface. Namely, the tribological behaviors of the crown‐type phosphate ionic liquids could be attributed to their stronger adsorption and tribochemical interactions with the Al alloys.

Because of the higher mean friction coefficients of crown‐type phosphate ionic liquids in the research, researchers are encouraged to modify their structure for better tribological properties.

The crown‐type phosphate ionic liquid exhibited better anti‐wear performance for steel/aluminum contact than the conventional ionic liquids containing F element. This will expand the application of high strength aluminum alloys.

The phosphate ionic liquid is a non‐corrosive liquid and would not cause metal corrosion. Also, the tribological properties of crown‐type phosphate ionic liquid with steel/aluminum contact are better than that of conventional ionic liquids. By the designing of molecular structure, new phosphate ionic liquids will exhibit excellent tribological properties: lower wear volume and lower friction coefficient.

The purpose of this paper is to detect and control the liquid‐level of stereolithography apparatus precisely.

A brightness‐variable laser source is adopted to remove the computational error of divider and a closed‐loop circuit is set to measure the terminal voltage directly proportional to the output current of photosensitive devices. It employs a sinking‐block device to control the liquid‐level.

The precise calibration result of this detecting device indicates that the resolution of the liquid‐level detection can reach ±1.5 μm.

This sinking‐block style liquid‐level control device can allow for the liquid‐level wave reduced from ±45 to ±15 μm.

The purpose of this paper is to explore the heat transfer and establish a heat transfer model of an extravehicular liquid cooling garment based on a thermal manikin covered with soft simulated skin.

The thermal manikin applied in this study was a copper manikin, typical of which was its soft simulated skin – a newly thermoplastic elastomer material. Based on this novel thermal manikin, the heat transfer analysis of an extravehicular liquid cooling garment was performed. To satisfy the practical engineering application and simplify analysis, the hypotheses were proposed, and then the heat transfer model was established by heat transfer theory, in which the heat exchange equation of the liquid cooling garment with the thermal manikin and with the air layer, and the garment's total heat dissipating capacity were derived.

The verification experiments performed in a climatic chamber by a thermal manikin wearing a liquid cooling garment at different surface temperatures of the thermal manikin show that the modeling value fits well with the experimental value, and the heat transfer model of the liquid cooling garment has a high accuracy. Meanwhile, the relationship between the heat‐dissipating capacity of the liquid cooling garment and its design parameters – inlet temperature and liquid velocity – is suggested as being based on the heat transfer model.

The paper shows that it is an effective method to control the heat‐dissipating capacity of a liquid cooling garment by changing the inlet temperature to some degree, but not by changing the liquid velocity.

When processing 11Cr-3Co-3W martensitic heat-resistant steel, the traditional pouring cooling method often appears large cutting force, high cutting temperature, serious tool wear and poor surface quality. This paper aims to use new cooling methods for processing this problem.

Different performance indicators such as cutting force, tool wear and surface quality were measured and analysed under different continuous milling times. The relationship between liquid nitrogen flow and cutting force and surface roughness was analysed and measured.

The results show that with the increase of liquid nitrogen flow, the cutting force decreases, especially the Fx component, which decreases by 10%. When the liquid nitrogen flow reaches 8 L/min, the effect of increasing the liquid nitrogen flow on reducing the cutting force becomes smaller. The cutting force reduced by up to 15%, and the tool life increased up to 20% using liquid nitrogen cryogenic cooling than in cutting liquids cooling. When minimal quantities of lubricant (MQL) was added, the cutting force was reduced by 23%, and the tool life increased by 25%. When the cutting speed increases from 100 m/min to 250 m/min, the cutting force with cutting liquid cooling does not change significantly while the cutting force with liquid nitrogen cooling decreases with the cutting speed increasing. It shows that liquid nitrogen cooling is more suitable for high-speed machining. After the cutting length reaches 66 m, the surface roughness of the workpiece using liquid nitrogen cooling method larger than that of the cutting liquid cooling method. When MQL is added into liquid nitrogen, the lubrication performance is improved, and the surface roughness of the workpiece is reduced about 8%.

Many studies had focused on the improvement of tool life and surface quality by different cooling methods, or on the injection process and chip mechanism. However, there are few relevant studies on the variation of cooling and lubrication properties with the change of cutting length in liquid nitrogen cryogenic processing. In this research, different performance indicators such as cutting force, tool wear and surface quality were measured and analysed under different continuous milling times. The relationship between liquid nitrogen flow and cutting force and surface roughness was analysed and measured.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0053/

The purpose of this paper is to study the dynamic characteristics of mechanical face seals with liquid-lubricated inclined elliptical grooves.

The steady-state and perturbation Reynolds control equations of liquid films were established. The film pressure and the liquid film dynamic coefficients were obtained, impacts of groove structures on the liquid film dynamic characteristic coefficients were analyzed.

The analysis results indicate that the axial dynamic stiffness and damping coefficients of the liquid film seal with inclined elliptical grooves are far greater than those of the angular directions. Furthermore, the dynamic stiffness coefficient of the liquid film with the nonclosed inclined elliptical grooves is higher than those with the closed grooves, whereas the dynamic damping coefficient of the liquid film is lower.

The effects of inclined elliptical groove structures on the dynamic characteristics of the liquid film seal are investigated. The results presented are expected to enrich the theoretical basis of optimizing the dynamic performance of liquid film seals with textures.

The purpose of this paper is to explore the tendencies of liquid consumption in Muslim communities and analyse its impact on Muslims’ consumption practices from the holistic perspective. Liquid consumption refers to a transient and less-materialised mode of consumption that requires both minimal attachment to possessions and hybrid ownership.

This is a conceptual paper that is based on the distinction between Islam as a holistic perspective and Islamic practice as it is applied in different contexts and situations. The Continual Drift Adjustment (CDA) framework of Muslim consumers’ behaviour is developed to be deployed as an analysis framework.

The CDA framework maintains that some problematic cases of Muslim consumption behaviours indicate the drift towards disbalance. Depending on their nature, liquid consumption practices can have different impacts on the drift. Liquid consumption practices underscored by instrumental dissemblance, intellectual insecurity and spiritual scepticism intensify the drift, whereas the incorporation of spiritual sincerity, faithful submission and existential gratefulness into practices and behaviour helps to attenuate the drift.

This research contributes to the theory of liquid consumption by incorporating the religious perspective. Liquid consumption in Islam is a complex area of research, specifically considering the ambivalent meanings of liquidity in Islamic thought.

Marketers of liquid consumption solutions must be aware of these offerings’ double-edged impact on the well-being of Muslim communities. Muslim consumers should be guided towards spiritual sincerity, faithful submission and existential gratefulness in the best way possible, although it must be noted that the customary techniques of marketing would lean towards stimulating the disbalance.

This research is unique because it deals with a topic that has not been researched in the Islamic marketing discipline to this date.

The purpose of this paper is to present the tribological, anticorrosion and antirust properties of three 2,5-dimercapto-1,3,4-thiadiazole (DMTD) derivatives as water-soluble additives in water–glycol hydraulic fluid.

DMTD derivatives possessing excellent corrosion inhibiting and extreme-pressure (EP) properties have long been used as metal passivators and load-carrying additives in lubricating oils and grease. However, there are seldom literatures about DMTD derivatives as water-soluble lubricant additives as yet. In this work, three DMTD derivatives were synthesized and investigated as water-soluble additives in the water–glycol hydraulic fluid. Their tribological properties were evaluated in detail by four-ball wear test machine and Optimol SRV-IV oscillating friction and wear tester. Meanwhile, their anticorrosion and antirust properties were also investigated by copper strip corrosive tests and antirust tests, respectively. The worn surfaces were analyzed by scanning electron microscope and X-ray photonelectron spectroscope, and the EP, antiwear and friction-reducing mechanisms were primarily proposed.

The synthesized three DMTD derivatives (coded as A, B and C) have excellent solubility in the base liquid of the water–glycol hydraulic fluid. The experimental results demonstrated that all these compounds, especially A, could remarkably improve the EP, antiwear and friction-reducing properties of the base liquid. Furthermore, they all have perfect copper corrosion inhibiting and antirust properties with low adding concentration (< 3 weight per cent) in the base liquid and hence could be used as multifunctional additives in the water–glycol hydraulic fluid.

This research only focused on the synthesized DMTD derivatives. If possible, some other thiadiazole derivatives also should be investigated.

The synthesized DMTD derivatives, especially compound A, can be used as multifunctional water-soluble additives in the water–glycol hydraulic fluid.

In this paper, three DMTD derivatives were synthesized and their tribological behaviors as water-soluble lubricant additives were investigated for the first time. In addition, the EP, antiwear and friction-reducing mechanisms were also put forward.

The paper aims to study the effect of liquid flow velocity on corrosion behavior of 20# steel at initial stage under (CO2/aqueous solution) gas–liquid two-phase plug flow conditions.

Weight loss, scanning electron microscopy, energy-dispersive X-ray spectroscopy and XPS methods were used in this study.

The corrosion rate increased with the increasing liquid flow velocity at any different corrosion time. The corrosion rate decreased with the extension of corrosion time at the same liquid flow velocity. There was no continuous corrosion products film on the whole pipe wall at any different corrosion time. The macroscopic brown-yellow corrosion products on the pipe wall surface decreased with the increasing liquid flow velocity and the loose floccus corrosion products decreased gradually until these products were transformed into un-continuous needle-like dense products with the increasing liquid velocity. The main elements among the products film were Fe, C and O, and the main phases of products film on the pipe wall were Fe3C, FeCO3, FeOOH and Fe3O4. When the corrosion time was 1 h under different liquid–velocity condition, the thickness of local corrosion products film was from 3.5 to 3.8 µm.

The ion mass transfer model of corrosion process in pipe was put forward under gas–liquid two-phase plug flow condition. The total thickness of diffusion sublayer and turbulence sublayer decreased as well as the turbulence propagation coefficient increased with the increasing liquid velocity, which led to the increasing velocity of ion transfer during corrosion process. This was the fundamental reason for the increase of corrosion rate with the increasing liquid velocity.