The effect of viscous dissipation and heat transfer on friction losses of grease-filled labyrinth seals

Augusto, L. L. X.; Takahama, Marcos Hiroshi; Negrão, Cezar Otaviano Ribeiro; Cousseau, Tiago

doi:10.1016/j.triboint.2020.106571

Cited by 8 publications

(2 citation statements)

References 28 publications

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“…In many studies for sealed bearings, the flow of grease was often discussed by the fluid models based on the Herschel-Bulkley model which focused on the rheological behavior of the bulk grease, although some models took the kinematic viscosity of the base oil into account for high shear rate conditions [21][22][23]. On contrast, this study indicated that not only the bulk grease fluidity but also the kinematic viscosity of the base oil in the grease had impact on the sealability of the metal-to-metal seal even under the extremely low shear rare conditions.…”

Section: Discussionmentioning

confidence: 99%

Fundamental Evaluation of Sealability of Greased Metal-to-Metal Seal on Premium Threaded Joints at High Pressure and High Temperature

2021

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Metal-to-metal seals in premium threaded joints (PJs) for Oil Country Tubular Goods are used in severe environments such as high pressure and high temperature. Under the extreme conditions, the thermal degradation of applied grease on the seal surfaces can affect the sealability of metal-to-metal seal. In this study, changes in the sealability of greased metal-to-metal seal due to elevated temperature were investigated by fundamental gas tightness tests. In addition, changes in grease property at high temperature were also investigated. It was found that one of the causes of the loss of the sealability of metal-to-metal seal at high temperature was the decrease in grease viscous resistance against high pressure due to thermal degradation of grease. The decrease in grease viscous resistance was caused by the decrease in the kinematic viscosity of the base oil under 125°C at which the network structure of the thickener was almost maintained. Beyond 150°C, the decrease of complex viscosity of the grease due to the collapse of the network structure of the thickener decreased the grease viscous resistance. The latter significantly affected the loss of sealability of the metal-to-metal seal.

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Section: Discussionmentioning

confidence: 99%

Fundamental Evaluation of Sealability of Greased Metal-to-Metal Seal on Premium Threaded Joints at High Pressure and High Temperature

2021

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“…They noted that the dissipation parameter caused an augmentation in thermal flow. Augusto et al [23] employed the concept of thermal flow and viscous dissipation for the reduction of friction inside a greasefilled labyrinth seal. They used an Arrhenius-type equation in their mathematical modeling.…”

Section: Introductionmentioning

confidence: 99%

Influences of Marangoni convection and variable magnetic field on hybrid nanofluid thin-film flow past a stretching surface

Khan¹,

Khan²,

Usman³

et al. 2022

Chinese Phys. B

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The investigations about thin-film flow play a vital role in the field of optoelectronics and magnetic devices. Thin films are reasonably hard and thermally stable but are more fragile. The thermal stability of thin film can be further improved by incorporating the effects of nanoparticles. In the current work, a stretchable surface is considered upon which hybrid nanofluid thin-film flow is taken into account. The idea of augmenting heat transmission is focused in current work by making use of hybrid nanofluid. The flow is affected by variations in the viscous forces along with viscous dissipation effects and Marangoni convection. A time-constrained magnetic field is applied in the normal direction to the flow system. The equations governing the flow system are shifted to a non-dimensional form by applying similarity variables. The homotopy analysis method (HAM) has been employed to find the solution of resultant equations. It has been noticed in this study that, the flow characteristics decline with augmentation in magnetic, viscosity, and unsteadiness parameters while grow up with enhancing values of thin-film parameter. Thermal characteristics are supported by the growing values of the Eckert number and unsteadiness parameter while opposed by the viscosity parameter and Prandtl number. The numerical impact of different emerging parameters upon skin friction and Nusselt number has been calculated in tabular form. A comparison of current work with established result has carried out with a good agreement in both results.

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Numerical Analysis of Magnetorheological Grease Flow Around Heated Rotating Rollers

Raj

Sarkar

Pathak

2023

Lecture Notes in Mechanical Engineering

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The effect of viscous dissipation and heat transfer on friction losses of grease-filled labyrinth seals

Cited by 8 publications

References 28 publications

Fundamental Evaluation of Sealability of Greased Metal-to-Metal Seal on Premium Threaded Joints at High Pressure and High Temperature

Fundamental Evaluation of Sealability of Greased Metal-to-Metal Seal on Premium Threaded Joints at High Pressure and High Temperature

Influences of Marangoni convection and variable magnetic field on hybrid nanofluid thin-film flow past a stretching surface

Numerical Analysis of Magnetorheological Grease Flow Around Heated Rotating Rollers

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