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Author

Satish C. Sharma

Other affiliations: Indian Institutes of Technology
Bio: Satish C. Sharma is an academic researcher from Indian Institute of Technology Roorkee. The author has contributed to research in topics: Bearing (mechanical) & Reynolds equation. The author has an hindex of 30, co-authored 233 publications receiving 3639 citations. Previous affiliations of Satish C. Sharma include Indian Institutes of Technology.


Papers
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Journal ArticleDOI
TL;DR: In this article, the effect of misalignment of journal in conjunction with geometric imperfections of journal on the performance of four pocket hybrid journal bearing system has been investigated and the numerically simulated results indicate that the performance gets significantly deteriorated due to the geometric imperfection and mis alignment of journal.

25 citations

Journal ArticleDOI
TL;DR: A comparative study of the performance of a multirecess flexible journal bearing using different types of compensations, namely capillary, constant flow valve, orifice and membrane restrictors, was carried out theoretically for hydrostatic as well as hybrid modes of operations.

24 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of wear on the performance of a non-circular 2-lobe four-pocket hybrid journal bearing system was investigated. But the bearing performance was not analyzed.
Abstract: Purpose – Noncircular journal bearings are used in industry because of their simplicity, efficiency and low cost. During the life time of a machine, these are required to be operated over a number of years and are submitted to several stops and starts. As a result, the bush becomes progressively worn out and the bearing performance changes. The purpose of this paper is to study theoretically the influence of wear on the performance of a non‐circular 2‐lobe four‐pocket multirecess hybrid journal bearing system.Design/methodology/approach – The Reynolds equation governing the flow of lubricant in the clearance space of a non‐circular 2‐lobe multirecess worn hybrid journal bearing system has been solved using FEM along with appropriate boundary conditions. The defects caused by wear are centered on the load line and range from 10 per cent to 50 per cent of the bearing radial clearance.Findings – The numerically simulated results based on a Newtonian lubricant and the steady state flow field system have been ...

24 citations

Journal ArticleDOI
TL;DR: In this paper, the combined influence of surface roughness and journal misalignment on the performance of an orifice compensated hole-entry hybrid journal bearing system is theoretically studied, and the results indicate that the effect of journal mis alignment is to lower the value of the minimum fluid-film thickness of the journal bearing, while the effect is to partially compensate this loss.
Abstract: The combined influence of surface roughness and journal misalignment on the performance of an orifice compensated hole-entry hybrid journal bearing system is theoretically studied. The analysis considers the average Reynolds equation for a rough surface for the solution of the lubricant flow field in the clearance space of a journal bearing system. The bearing performance characteristics are presented for the various representative values of surface roughness parameter (Λ) and surface pattern parameter (γ) for a concentric design pressure ratio β* = 0.5. Performance is also compared to capillary and constant flow valve compensated bearings. The computed results indicate that the effect of journal misalignment is to lower the value of the minimum fluid-film thickness of the journal bearing system while the effect of surface roughness is to partially compensate this loss. For the chosen values of journal misalignment parameters (ϕ, δ), the constant flow valve compensated symmetric journal bearing configurat...

23 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of wear on the performance of a capillary-compensated, four pocket, hybrid journal bearing system operating in a turbulent regime by considering various geometric shapes of recess was analyzed.
Abstract: The objective of the present paper is to study analytically the influence of wear on the performance of a capillary-compensated, four-pocket, hybrid journal bearing system operating in a turbulent regime by considering various geometric shapes of recess. The present study deals with bearings having four different geometric shapes of recess, i.e., square, circular, elliptical, and triangular recessed bearings. The wear on the bearing surface is modeled using Dufrane's abrasive wear model. The Reynolds equation based on Constantinescu's turbulent lubrication theory has been solved using finite element method along with a restrictor flow equation as a constraint together with appropriate boundary conditions. The numerically simulated results have been presented for a wide range of nondimensional external loads, wear depth parameters, and Reynolds numbers. The numerically simulated results suggest that the combined influence of wear, turbulence, and geometric shape of recess significantly affects the bearing performance. It has been observed that a triangular recessed bearing provides a greater value of minimum fluid film thickness when operating in a turbulent regime. It is also noticed that direct fluid film stiffness coefficients get reduced significantly when bearings operate in a turbulent regime compared with a laminar regime. Further, it is observed that from the viewpoint of fluid film stiffness, a square recessed bearing is found to be most suitable when operating in a turbulent regime.

23 citations


Cited by
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Journal ArticleDOI
TL;DR: This paper attempts to present a comprehensive review of AI algorithms in rotating machinery fault diagnosis, from both the views of theory background and industrial applications.

1,287 citations

Journal ArticleDOI
TL;DR: Current applications of wavelets in rotary machine fault diagnosis are summarized and some new research trends, including wavelet finite element method, dual-tree complex wavelet transform, wavelet function selection, newWavelet function design, and multi-wavelets that advance the development of wavelet-based fault diagnosed are discussed.

1,087 citations

Journal ArticleDOI
TL;DR: A feature learning model for condition monitoring based on convolutional neural networks is proposed to autonomously learn useful features for bearing fault detection from the data itself and significantly outperforms the classical feature-engineering based approach which uses manually engineered features and a random forest classifier.

871 citations

Journal ArticleDOI
TL;DR: This review covers advances in electrochemical and biochemical sensor development and usage during 2010 and 2011 and focuses on novel methods and materials, with a particular focus on the increasing use of graphene sheets for sensor material development.
Abstract: This review covers advances in electrochemical and biochemical sensor development and usage during 2010 and 2011 In choosing scholarly articles to contribute to this review, special emphasis was placed on work published in the areas of reference electrodes, potentiometric sensors, voltammetric sensors, amperometric sensors, biosensors, immunosensors, and mass sensors In the past two years there have been a number of important papers, that do not fall into the general subsections contained within the larger sections Such novel advances are very important for the field of electrochemical sensors as they open up new avenues and methods for future research Each section above contains a subsection titled “Other Papers of Interest” that includes such articles and describes their importance to the field in general For example, while most electrochemical techniques for sensing analytes of interest are based on the changes in potential or current, Shan et al1 have developed a completely novel method for performing electrochemical measurements In their work, they report a method for imaging local electrochemical current using the optical signal of the electrode surface generated from a surface plasmon resonance (SPR) The electrochemical current image is based on the fact that the current density can be easily calculated from the local SPR signal The authors demonstrated this concept by imaging traces of TNT on a fingerprint on a gold substrate Full articles and reviews were primarily amassed by searching the SciFinder Scholar and ISI Web of Knowledge Additional articles were found through alternate databases or by perusing analytical journals for pertinent publications Due to the reference limitation, only publications written in English were considered for inclusion Obviously, there have been more published accounts of groundbreaking work with electrochemical and biochemical sensors than those covered here This review is a small sampling of the available literature and not intended to cover every advance of the past two years The literature chosen focuses on new trends in materials, techniques, and clinically relevant applications of novel sensors To ensure proper coverage of these trends, theoretical publications and applications of previously reported sensor development were excluded We want to remind our readers that this review is not intended to provide comprehensive coverage of electrochemical sensor development, but rather to provide a glimpse of the available depth of knowledge published in the past two years This review is meant to focus on novel methods and materials, with a particular focus on the increasing use of graphene sheets for sensor material development For readers seeking more information on the general principles behind electrochemical sensors and electrochemical methods, we recommend other sources with a broader scope2, 3 Electrochemical sensor research is continually providing new insights into a variety of fields and providing a breadth of relevant literature that is worthy of inclusion in this review Unfortunately, it is impossible to cover each publication and unintentional oversights are inevitable We sincerely apologize to the authors of electrochemical and biochemical sensor publications that were inadvertently overlooked

727 citations