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Showing papers by "Satish C. Sharma published in 2019"


Journal ArticleDOI
TL;DR: In this article, the influence of micro-texture with different shapes used on the bearing surface is studied and a parametric study is carried out to optimize the dimple attributes on the basis of radial load.

18 citations


Journal ArticleDOI
TL;DR: In this article, a numerical simulation is performed to investigate the synergizing influence of surface texture (micro-grooves) and electrically conducting lubricant on static and dynamic performance of hybrid thrust pad bearings operating under transverse magnetic field.
Abstract: A numerical simulation is performed to investigate the synergizing influence of surface texture (micro-grooves) and electrically conducting lubricant on static and dynamic performance of hybrid thrust pad bearings operating under transverse magnetic field. Linear momentum and mass conservation equation are solved simultaneously to derive modified Reynolds equation for magnetohydrodynamic lubrication. Finite element approach has been used to obtain couple solution of modified Reynolds equation and restrictor (orifice) flow equation. A mass conserving algorithm (Jakobsson–Floberg–Olsson boundary condition) has been implemented to simulate cavitation phenomenon within micro-grooves. A parametric investigation (based on load-carrying capacity/fluid film pressure) is carried out to obtain optimum attributes for various micro-grooves shapes. Providing micro-groove on bearings surfaces results in a significant increase in load-carrying capacity, stiffness coefficient and reduction in frictional power loss of the bearing. Employing of electrically conducting lubricant is seen to be enhancing the load-carrying capacity and damping characteristics of the bearing.

12 citations


Journal ArticleDOI
TL;DR: In this article, numerical simulations are carried out to examine the influence of surface texture on performance of hybrid thrust bearing system and determine optimum attributes of micro-groove for thrust bearing operating in hybrid mode.
Abstract: Micro-surface texturing is emerging as a possible way to enhance the tribological performance of hydrodynamic fluid film bearings. In view of this, numerical simulations are carried out to examine the influence of surface texture on performance of hybrid thrust bearing system. This paper aims to determine optimum attributes of micro-grooves for thrust bearing operating in hybrid mode.,An iterative source code based on finite element formulation of Reynolds equation has been developed to numerically simulate flow of lubricant through the bearing. Mass-conserving algorithm based on Jakobsson–Floberg–Olsson (JFO) condition has been used to numerically capture cavitation phenomenon in the bearing. Gauss Siedel method has been used to obtain steady state performance parameters of the bearings.,A parametric study has been performed to improve the load supporting capacity of the bearing by optimizing micro-groove attributes and configuration. It is noticed that use of full-section micro-groove is beneficial in improving the efficiency of bearing by enhancing the fluid film reaction and reducing the film frictional power losses.,This study is helpful in examining the usefulness of micro-groove textured surfaces in hybrid thrust bearing applications.

11 citations


Journal ArticleDOI
TL;DR: In this article, the influence of magnetic field and recess configurations on the performance of a bearing has been numerically investigated and the effect of the geometrical shape of the recess and restrictor has been investigated.
Abstract: Purpose This paper aims to numerically investigate the influence of magnetic field and recess configurations on performance of hydrostatic thrust bearing. Electrically conducting fluid is supplied to bearing, operating in external magnetic field. Influences of recess geometric shapes (circular, rectangular, elliptical and triangular) and restrictor (capillary and orifice) are numerically examined on stead-state and dynamic performance characteristics of bearing. Design/methodology/approach Numerical simulation of hydrostatic thrust bearing has been performed using finite element (FE) method based on Galerkin’s technique. An iterative source code based on FE approach, Gauss–Siedel and Newton–Raphson method is used to compute steady-state and dynamic performance indices of bearings. Findings The presence of magnetic field is observed to be enhancing load-carrying capacity and damping coefficient of bearings. The effect is observed to be more pronounced at low value of Hartmann number, because of the saturation effect observed at higher values of Hartmann number. The enhancement in abovementioned performance indices is observed to be highly dependent on geometry of recess and restrictor. Research limitations/implications This study presents a FE-based approach to numerically simulate a hydrostatic thrust bearing. It will help bearing designers and academician in selecting an appropriate recess shape, restrictor and strength of magnetic field, for obtaining optimum performance from hydrostatic thrust bearing. Originality/value The present investigation provides a coupled solution of modified Reynolds equation and restrictor equation, which is essential for accurately predicting the performance of hydrostatic thrust bearings.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the numerical simulation of a fluid film bearing was used to control the performance of fluid film bearings smartly, which has become an important area for the fluid-film bearing designers.
Abstract: In recent times, controlling the performance of fluid film bearings smartly has become an important area for the fluid film bearing designers. This study deals with the numerical simulation of a ma...

10 citations


Journal ArticleDOI
TL;DR: In recent years, extensive use of smart lubricants has been made in order to control the tribological performance of fluid film bearings as mentioned in this paper, and the grooved surfaces of the journal bearing greatly influen...
Abstract: In recent years, extensive use of smart lubricants has been made in order to control the tribological performance of fluid film bearings. The grooved surfaces of the journal bearing greatly influen...

9 citations


Journal ArticleDOI
TL;DR: In this paper, the micro-groove attributes have been optimized by obtaining the solution of a Reynolds equation using finite element method and generalized minimum residual scheme (GMRES) for numerically simulating the performance of the conical bearings.
Abstract: To harness higher axial load capacity, a larger cone angle is used in conical bearings, resulting in an increase in the surface area which in turn increases the frictional power loss. The use of microgrooves in journal bearing helps in controlling this loss. Therefore, the present work is aimed to analyze conical hybrid journal bearing (i.e., combination of hydrostatic and hydrodynamic modes of operation) consisting of microgrooves along with shear thinning and piezo-viscous behavior of the lubricant. In this study, the microgroove attributes have been optimized by obtaining the solution of a Reynolds equation using finite element method and generalized minimum residual scheme (GMRES). These optimized groove attributes are used for numerically simulating the performance of the conical bearings. It has been observed that the best features of microgrooves and shear thinning behavior of the lubricant can be extracted to achieve better performance of the bearings. The results presented in this study are believed to be beneficial to the bearing designers and practising lubrication engineers.

8 citations


Journal ArticleDOI
01 Jun 2019
TL;DR: In this article, an investigation has been performed on a rigid rotor supported by two-lobe journal bearings operating with a non-Newtonian lubricant, and the governing Reynolds equation for pressu...
Abstract: In the present work, an investigation has been performed on a rigid rotor supported by two-lobe journal bearings operating with a non-Newtonian lubricant. The governing Reynolds equation for pressu...

6 citations


Journal ArticleDOI
TL;DR: In this paper, the combined effect of micro-texture and magneto hydrodynamic lubrication behavior on the performance of EHL line contact was investigated using FEA and Generalized Minimal residual method (GMRES).
Abstract: The present numerical study investigates the combined effect of micro-texture and magneto hydrodynamic lubrication behaviour on the performance of EHL line contact. Micro-textures are provided in the inlet zone of contacting surface has been studied. Modified Reynolds equation, elasticity equation and load balance equation has been solved using FEA and Generalized Minimal Residual Method (GMRES). A parametric study has been performed to optimize the micro-texture shapes in the contacting surfaces for different values of magneto hydrodynamic lubricant parameters The numerical results show that increasing externally applied magnetic field and micro- texture shapes enhances the values of performance parameter of EHL line contact. Finally, the variation in the steady-state EHL characteristics pertaining to unidirectional pure sliding contacts due to an artificially produced IZMTS is investigated numerically. The enhancement in central and minimum film thickness is found to be upto 38% and 28% respectively along with 33.28% reduction in coefficient of friction.

3 citations


Journal Article
TL;DR: Due to dominance of fluorescent pseudomonads in the rice rhizosphere and diverse mechanism of action, it had the potential for reducing sheath blight incidence of rice caused by R. solani.
Abstract: Aim: The present study was conducted to investigate the biocontrol potential of fluorescent pseudomonads in- vitro and in-vivo responsible for causing sheath blight of rice. Methodology: Indigenous isolates (20 nos.) of fluorescent pseudomonads, collected from the rhizosphere of basmati paddy fields from different locations of Jammu province, which were further characterized for their bio-control activity against Rhizoctonia solani causing sheath blight of rice under laboratory and glasshouse conditions at Division of Plant Pathology, Faculty of Agriculture, SKUAST- Jammu, ChathaResults: On the basis of biochemical tests, isolate Fp1, Fp2, Fp4, Fp5, Fp6, Fp7, Fp9, Fp11, Fp17 and Fp18 were able to grow at 4°C and were identified as Pseudomonas fluorescens, whereas, isolate Fp3, Fp8, Fp10, Fp12, Fp13, Fp14, Fp15, Fp16, Fp19 and Fp20 which grew at 41°C and utilized the acetamide were identified as Pseudomonas aeruginosa. Under in vitro conditions, out of ten isolates (Fp1- Fp10), Fp6 showed maximum per cent inhibition (84.09 and 86.66) of mycelial growth of R. solani, followed by Fp1 (81.81and 84.89), whereas, minimum inhibition was observed by Fp8 (43.40 and 64.00) on PDA and NA media, respectively, using dual culture assay. All the isolates reduced the germination of R. solani sclerotia with range of 49.05-90.87% and also enhanced the vigour index of the rice seedlings ranging from 595.05 to 1683.27. In detached leaf assay rice leaves treated with suspension of Fp6 isolate significantly showed minimum lesion length (12.66 mm) with maximum per cent reduction of lesion (81.91%) as compared to untreated control (70.00 mm). The treatment T4 (P. fluorescens) and T8 (P. aeruginosa) (seed soaking + seedling dip +foliar spray) showed disease intensity of 10.94 and 14.06 per cent with 42.19 and 39.07 per cent disease reduction, respectively, as compared to untreated control. Interpretation: Due to dominance of fluorescent pseudomonads (P. fluorescens and P. aeruginosa) in the rice rhizosphere and diverse mechanism of action, it had the potential for reducing sheath blight incidence of rice caused by R. solani.

1 citations


Journal ArticleDOI
01 Jul 2019
TL;DR: In this article, the influence of elastohydrostaic lubrication on orifice compensated bearing has been shown, where the thrust pad has been modeled by using three-dimensional mesh and the lubrication domain has been modelled by using two dimensional mesh.
Abstract: In the present work influence of elastohydrostaic lubrication on orifice compensated bearing has been shown. The thrust pad has been modeled by using three-dimensional mesh and lubrication domain has been modeled by using two dimensional mesh. The analysis of Reynold equation is coupled with the analysis of solution of equilibrium equation of thrust pad domain. The Present results shows that elasticity of thrust pad results a significant decrement in the fluid film Elasticity and it results an increase in fluid film stiffness. In the present case Circular, Elliptical, square and rectangular shape of recess has been taken from the analysis.