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In a harmonic drive during assembly of its components like strain wave generating (SWG) cam, flexspline (FS) and circular spline, a gap is formed between the cam’s outer surface and the FS cup inner surface due to mismatching. This gap, which is known as “Coning”, plays a vital role in the flow of lubricant at that interface. This paper aims to analyse the coning phenomenon and the lubrication mechanism.

In the present investigation, the geometry of the coning gap and its variation with the SWG cam rotation are established. Essentially, the deflection of FS cup and deformation of SWG cam (bearing outer race) are derived to find the gap due to coning. Next, the hydrodynamic lubrication equation is solved to get pressure profiles for this gap under suitable boundary conditions assuming non-Newtonian lubrication.

Methods of estimating the coning gap and lubrication pressure profiles are established. Effects of non-Newtonian terms (coupling number and non-dimentionalized characteristic length) and SWG length (finite, long and short) on pressure profiles are also shown. All analyses are done in non-dimensionalized form.

Establishing the geometry of coning and non-Newtonian hydrodynamic lubrication aspects in the coning in the FS cup and SWG cam interface are the originality of the present investigation.

The purpose of this paper was to study laminar fluid flow and convective heat transfer in a conical gap at small conicity angles up to 4° for the case of disk rotation with a fixed cone.

In this paper, the improved asymptotic expansion method developed by the author was applied to the self-similar Navier–Stokes equations. The characteristic Reynolds number ranged from 0.001 to 2.0, and the Prandtl numbers ranged from 0.71 to 10.

Compared to previous approaches, the improved asymptotic expansion method has an accuracy like the self-similar solution in a significantly wider range of Reynolds and Prandtl numbers. Including radial thermal conductivity in the energy equation at small conicity angle leads to insignificant deviations of the Nusselt number (maximum 1.23%).

This problem has applications in rheometry to experimentally determine viscosity of liquids, as well as in bioengineering and medicine, where cone-and-disk devices serve as an incubator for nurturing endothelial cells.

The study can help design more effective devices to nurture endothelial cells, which regulate exchanges between the bloodstream and the surrounding tissues.

To the best of the authors’ knowledge, for the first time, novel approximate analytical solutions were obtained for the radial, tangential and axial velocity components, flow swirl angle on the disk, tangential stresses on both surfaces, as well as static pressure, which varies not only with the Reynolds number but also across the gap. These solutions are in excellent agreement with the self-similar solution.

This quasi-experimental study aimed to investigate, drawing upon influential discounting behavior theory and cognition – affect – behavior (C-A-B) paradigm, consumers’ reactions to the phenomenon of “greenwashing” in the lodging industry. More specifically, this paper proposed and tested a theoretical model that examined whether recognizing the ulterior motive caused consumer skepticism about hotels’ environmental claims, which in turn influenced consumers’ intention to participate in linen reuse program and intention to revisit the hotel. Additionally, the moderating effects of ecological concern on the relationship between skepticism and intention to participate and between skepticism and intention to revisit were examined.

A quasi-experimental design was used with two conditions (control vs ulterior motive) employing staff members of a US public university as study participants. In total, 638 useful responses were received.

The results of this study revealed that an ulterior motive of hotels’ environmental claims evoked consumer skepticism, which, in turn, negatively influenced consumers’ intention to participate in the linen reuse program and intention to revisit the hotel. Skepticism was found to partially mediate the relationships between ulterior motive and intention to participate and between ulterior motive and intention to revisit. Consumers’ ecological concern was not found to moderate the relationship between skepticism and intention to participate in the linen reuse program and skepticism and intention to revisit the hotel. In addition, a significant positive direct effect between ecological concern and intention to participate and a non-significant effect between ecological concern and revisit intention were revealed.

Focus on consumers’ response to the ulterior motive of environmental claims advances an understanding of consumers’ attitudes and perceptions about hotels’ green practices.

Findings suggest that hotels need to be watchful so that consumers do not become skeptical. Therefore, it is of utmost importance that managers do everything possible to give customers no room for doubt. Hoteliers need to spend more effort in installing comprehensive green programs and make true green claims by keeping the potential consequences of greenwashing in mind. Hoteliers also need to seek out third-party certifications that require the hotel to meet certain standards, which will help ensure credibility in the eyes of consumers.

Hospitality literature has seldom explored this gray area of green marketing, and, in this regard, this study serves as a guide to hoteliers and researchers alike. The authors thereby anticipate that this study would encourage more research in this often overlooked but highly important area.

Thus, the purposes of this study are to study the limits of applicability of the self-similar solution to the problem of fluid flow, heat and mass transfer in conical gaps with small conicity angles, to substantiate the impossibility of using a self-similar formulation of the problem in the case of large conicity angles and to substantiate the absence of the need to take into account the radial thermal conductivity in the energy equation in its self-similar formulation for the conicity angles up to 4°.

In the present work, an in-depth and extended analysis of the features of fluid flow and heat transfer in a conical gap at small angles of conicity up to 4° is performed. The Couette-type flow arising, in this case, was modeled using a self-similar formulation of the problem. A detailed analysis of fluid flow calculations using a self-similar system of equations showed that they provide the best agreement with experiments than other known approaches. It is confirmed that the self-similar system of flow and heat transfer equations is applicable only to small angles of conicity up to 4°, whereas, at large angles of conicity, this approach becomes unreasonable and leads to significantly inaccurate results. The heat transfer process in a conical gap with small angles of conicity can be modeled using the self-similar energy equation in the boundary layer approximation. It was shown that taking into account the radial thermal conductivity in the self-similar energy equation at small conicity angles up to 4° leads to maximum deviations of the Nusselt number up to 1.5% compared with the energy equation in the boundary layer approximation without taking into account the radial thermal conductivity.

It is confirmed that the self-similar system of fluid flow equations is applicable only for small conicity angles up to 4°. The inclusion of radial thermal conductivity in the model unnecessarily complicates the mathematical formulation of the problem and at small conicity angles up to 4° leads to insignificant deviations of the Nusselt number (maximum 1.5%). Heat transfer in a conical gap with small conicity angles up to 4° can be modeled using the self-similar energy equation in the boundary layer approximation.

This paper investigates the question of the validity of taking into account the radial heat conduction in the energy equation.

The fluid flow and heat transfer between a rotating cone above a stretching disk is the prime purpose of the current work. Making use of suitable similarity transformations, it is shown that the physical phenomenon is represented by a system of similarity equations, which is compatible with that of literature in the absence of wall expansion.

Numerical simulation of the system enables us to seize the physical character of fluid filling the conical section as well as of the heat transfer, from small to adequately large gap sizes. How the surface expansion will contribute to the momentum and thermal layers; moreover, to the swirl angle from the disk wall, and heat transports from the cone and disk surfaces is studied in detail.

The results are clear evidences that the wall stretching completely changes the flow and heat behaviors within the conical gap. For instance, the centripetal/centrifugal flow properties of disk/cone are completely altered and the flow swirling angles are increased by means of the wall deformation.

The original value is that at small gap angles faster expansion of the wall overall leads to near-disk surface cooling, while causing the heated region near the cone surface, which has physical implications in practical applications.

One of the crucial steps in the molded bra production is the process of developing the mold head. The purpose of this paper is to determine the final cups style and size. Compared with traditional development process of the mold head, less time-consuming and a more quantitative method is needed for the design and modification of the mold head.

A three-dimensional (3D) numerical model for the simulation of large compressive deformation was built in this paper to research the foam bra cup molding process. Since the head cones have more representative than the mold heads, the male and female head cones were used in the simulation. All of the solid shapes are modeled by using 3D Solid 164 elements as well as an automatic surface-to-surface contact between head cones.

Simulation of the foam cup molding process is conducted by inputting different properties of the foam material and stress-strain curves under different molding temperatures.

In order to simulate the laminated foam moulding process, heat transfer through a layered textile assembly can be studied by using the thermo-mechanical coupled FE model.

According to the different foam performance parameters under different temperatures along with different head cone shapes, distribution and variation in the stress field can be obtained as well as the ultimate capacity of foam materials.

A computer-aided parametric design system for the mold heads provides an effective solution to improving the development process of mold heads.

The distribution and variation in the stress fields can be analyzed through simulation, providing a reference for the mold head design.

This paper aims to study the fluid flow and heat transfer within the Casson nanofluid confined between disk and cone both rotating with distinct velocities. For a comprehensive investigation, two distinct nano-size particles, namely, silicon dioxide and silicon carbide, are submerged in ethanol taken as the base fluid.

This paper explores the disk and cone contraption mostly encountered for viscosity measurement in various industrial applications such as lubrication industry, hydraulic brakes, pharmaceutical industry, petroleum and gas industry and chemical industry.

It is worth mentioning here that the radially varying temperature profile at the disk surface is taken into the account. The effect of prominent emerging parameters on velocity fields and temperature distribution are studied graphically, while bar graphs are drawn to examine the physical quantities of industrial interest such as surface drag force and heat transfer rate at disk and cone.

To the best of the authors’ knowledge, no study in literature exists that discusses the thermal enhancement of nano-fluidic transport confined between disk and cone both rotating with distinct angular velocities with heat transfer.

Bearing and lubrication arrangements which prolong the life of one of the toughest types of machine used in the construction industry

The purpose of this study with the rapid development of the heavy/large mechanical equipment, the heavy computer numerical control (CNC) vertical lathe has become the ideal processing equipment for the parts of those mechanical equipments. The main factor which affects the machining quality and efficiency of heavy CNC vertical lathe is the mechanical properties of the hydrostatic thrust bearing.

This paper did the research based on the large size sector oil pad’s lubrication performance of the hydrostatic thrust bearing in the heavy/large equipments, establishing the lubrication performance distribution mathematical model of the velocity field, flow field, pressure field and so on, analyzing the bearing behavior of the large size sector oil pad.

The results show that the oil flow generated by the plate relative motion will be greater than that generated by the pressure difference in area B, with the rotational speed’s increasing of the hydrostatic thrust bearing, and the direction is opposite. The oil flow generated by the centrifugal force will be greater than that generated by the pressure difference in area C, with the rotational speed’s increasing of the hydrostatic thrust bearing, and the direction is opposite. When the rotational speed of the hydrostatic thrust bearing is too high, the friction heat will be not easy to be sent out. The bearing rotating speed should be lower than the comparatively smaller one of ω1 and ω2, which can help avoid the rise of too high temperature.

The research provides powerful theoretical foundation for practical application of the large size sector oil pad hydrostatic thrust bearing, its structure design and operating reliability, realizing the lubrication performance prediction of the large size hydrostatic thrust bearing.

A non‐contact end‐effector was applied to lift three different materials which have different physical properties. These materials are mica (as rigid material), carton (as semi‐rigid material) and non‐rigid material (woven fabric). This end‐effector operates on the principle of generating a high‐speed air flow between nozzles and the specimen surface thereby creating a vacuum which levitates the materials with no mechanical contact. In this paper, the handling results of these materials are compared with each other. The changes in the physical behavior of lifting materials were observed during the experimental work. The effect of the various air flow rates on the non‐contact handling clearance gap between the nozzle and the materials were also investigated. As a result, it was observed that the non‐contact end‐effector could be applied to handle different flat materials.