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IT MAY reasonably be asked “why should metalworking lubricants be considered as a class on their own?” Apart from convenience of classification, there are at least three good reasons for doing so:

The purpose of this paper is to verify the ability of our in-house solver naoe-FOAM-SJTU to solve the problem of exterior fluid field coupled with interior fluid field and discover the coupling effects between exterior field (ship motion) and interior field (sloshing tanks).

The solving equation is based on Navier–Stokes equation, by comparing two turbulence models [laminar model and Reynolds-averaged Navier–Stocks (RANS)], of which RANS model are chosen to do the simulation. A unified approach is adopted to simulate exterior and interior fields simultaneously, keeping the pressure and velocity the same in external and internal fields. By adding a new function of calculating forces on different patches, the inner sloshing moments and external wave exciting moments can be output.

The in-house solver naoe-FOAM-SJTU had the ability to simulate this problem and showed well agreement with experimental results. By considering ship motion with and without sloshing, it was figured that with the existence of sloshing tank, the ship natural frequency will be changed. When the two tank fillings are the same, there will be another roll peak appeared, which is natural frequency of sloshing tanks. Considering wave height and different filling influence, the nonlinearity of sloshing in tank may give non-proportional response to ship motion.

With the ability to simulate well, the reality reference in the progress of FPSO or FLNG operation is obtained.

The value of this paper is a fully coupled CFD method which is adopted to solve the coupling effects, showing the ability to do the work well. It gives a referenced detailed information of inner and outer fluid field. Meanwhile, it carried out the impact pressure and damping force around the ship, which indicates the practical information in operations.

A LUBRICATING oil may have several duties to perform in addition to acting as a lubricant. It may have to act as a coolant and carry frictional temperature to where it can be easily dissipated to atmosphere, it may have to operate hydraulic or other mechanically operated control or governor gear, it may have to act as an insulating oil, it may have to effect a seal against escape of exhaust gases or a seal between piston and rings. However, the main duty of any lubricant will be to reduce friction between moving surfaces. In order to obtain a clear understanding of how a lubricant can reduce frictional resistance, it is necessary to know the fundamental theories concerning friction and to know the rules of friction. Friction obeys certain rules whereby its value, or its powers of resistance, can be calculated sufficiently accurately for most designer's purposes.

The purpose of this paper is to determine the thermo-gravitational convective state of a non-Fourier fluid layer of the single-phase-lagging type, heated from below. Unlike existing methodologies, the spectral modes are not imposed arbitrarily. They are systematically identified by expanding the spectral coefficients in terms of the relative departure in the post-critical Rayleigh number (perturbation parameter). The number and type of modes is determined to each order in the expansion. Non-Fourier effects become important whenever the relaxation time (delay in the response of the heat flux with respect to the temperature gradient) is of the same order of magnitude as process time.

In the spectral method the flow and temperature fields are expanded periodically along the layer and orthonormal shape functions are used in the transverse direction. A perturbation approach is developed to solve the nonlinear spectral system in the post-critical range.

The Nusselt number increases with non-Fourier effect as suggested in experiments in microscale and nanofluid convection.

Unlike existing nonlinear formulations for RB thermal convection, the present combined spectral-perturbation approach provides a systematic method for mode selection.

This paper studies elastohydrodynamic lubrication (EHL) of line contacts for the slide‐roll ratios 0‐2 based on the assumptions of interfacial shear strength and interfacial slip. It is shown that the viscoelastic, viscoplastic and non‐continuum fluids distribute from the inlet zone to the Hertzian contact zone in order for a given operating condition when the load and rolling speed exceed critical values. For the rolling speed below the critical, the distributing fluids from the inlet zone to the Hertzian contact zone in order are viscoelastic and non‐continuum when the load exceeds a critical value. These show a multirheological behavior EHL film, formed in a contact, which may represent a mode of mixed lubrication. For this mode of lubrication, the fluid model should handle both inlet and Hertzian contact zones where the fluids are, respectively, continuum and non‐continuum. A new EHL analysis and theory, therefore needs to be established.

To present some new designs of magnetic fluid exclusion seals for rolling bearings and possibility to use them in modern industrial sealing applications.

In the paper is given principle of magnetic fluid sealing technology and are presented new designs of magnetic fluid exclusion seals for rolling bearings, such as compact magnetic fluid seals, two‐stages seals being combination of magnetic fluid seal and labyrinth seal or radial lip seal, magnetic fluid seals with “floating” magnetic system. This paper also shows examples of their application in various rotating process equipment.

Provides information about new designs of bearing seals and gives the main advantages of these seals over other types, such as total tightness, low viscous drag, maintenance‐free service and high reliability.

This paper offers some new designs of high‐performance magnetic fluid exclusion seals for rolling bearings and points their practical applications.

The purpose of this paper is to discuss the asymptotic models of different parts with a pitting fault in rolling bearings.

For rolling bearings with a pitting fault, the displacement deviation between raceways and rolling elements is usually considered to vary instantaneously. However, the deviation should change gradually. Based on this shortcoming, the variation rule and calculation method of the displacement deviation are explored. Asymptotic models of different parts with a pitting fault are discussed, respectively. Besides, rolling bearing systems have prominent fractional characteristics unconsidered in the traditional models. Therefore, fractional calculus is introduced into the modeling of rolling bearings. New dynamic asymptotic models of different parts with a pitting fault are proposed based on fractional damping. The numerical simulation is performed based on the proposed model, and the dynamic characteristics are analyzed through the bifurcation diagrams, trajectory diagrams and frequency spectrograms.

Compared with the model based on integral calculus, the proposed model can better reflect the periodic characteristics and fault characteristics of rolling bearings. Finally, the proposed model is verified by the experiment. The dynamic characteristics of rolling bearings at different rotating speeds are analyzed. The experimental results are consistent with the simulation results. Therefore, the proposed model is effective.

(1) The above models are idealized, i.e. the local pitting fault is treated as a rectangle. When a component comes into contact with the fault, the displacement deviation between the component and the fault component immediately releases if the component enters the fault area and restores if the component leaves. However, the displacement deviation should change gradually. Only when the component touches the fault bottom, the displacement deviation reaches the maximum. (2) Due to the material's memory and fluid viscoelasticity, rolling bearing systems exhibit significant fractional characteristics. However, the above models are all proposed based on integral calculus. Integral calculus has some local characteristics and is not suitable for describing historical dependent processes. Fractional calculus can better describe the essential characteristics of the system.

Sendzimir mills have already been referred to as notable examples of cluster mills (p. 142 and Fig. 9). They exploit the advantages of well‐supported small diameter work rolls, making heavy reductions possible and producing very accurate cold rolled strip. The work rolls can be finished to produce the sheet surface quality required, can be very rapidly changed in service, and can be made of special very hard material such as tungsten carbide when minimum flattening is needed. Accordingly these mills are used for a great variety of materials — not only all types of steel (including stainless), copper and its alloys, and aluminium and its alloys, but titanium, tantalum, zirconium and even rarer or more intractable metals.

AFTER cutting oils, rolling oils probably constitute the next largest overall offtake of metalworking oils although the proportions for any individual supplier may be very different, since much of the business is in the hands of specialists and some of the largest companies may do little.

The objective of this paper is to measure the differences in heat transfer properties of refined hydrocarbon distillate fractions that are commonly used as base oils in aluminium sheet cold rolling applications and assess if the heat transfer coefficient (HTC) values for these oils can be predicted from their compositions. The composition and physical properties of these fluids affect their tribological behaviour by influencing hydrodynamic lubrication, wear debris removal and cooling.

A purpose-built test rig was used to measure HTCs for a wide range of hydrocarbon solvents used as aluminium cold rolling oils. The results are expressed in the form of the HTCs relative to those of 14- to 16-carbon-chain-length normal paraffins. Measured HTC values were compared to values calculated from oil compositions and from the thermal conductivities of compounds representing different classes of typical oil components.

There were significant differences between the heat transfer properties of various hydrocarbon solvents, and these differences could be estimated from their content of normal and simple iso-paraffins and heavily branched and cyclic hydrocarbons. The HTC of hydrocarbon mixtures increases with the increasing content of n-paraffinic compounds.

This paper shows how one can estimate the relative HTCs of oils of known compositions, based on the relative thermal conductivities of model compounds. This is relevant to prediction of cooling properties of aluminium cold rolling base oils.