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Article
Publication date: 13 November 2017

Chandra B. Khatri and Satish C. Sharma

The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid…

Abstract

Purpose

The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing.

Design/methodology/approach

In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique.

Findings

The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing.

Originality/value

The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.

Details

Industrial Lubrication and Tribology, vol. 69 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 3 August 2018

Krishnkant Sahu and Satish C. Sharma

This study aims to deal with the performance of symmetric/asymmetric slot entry hybrid journal bearing system considering the effect of three dimensional irregularities in…

Abstract

Purpose

This study aims to deal with the performance of symmetric/asymmetric slot entry hybrid journal bearing system considering the effect of three dimensional irregularities in the analysis.

Design/methodology/approach

The asperity profile of three-dimensional irregularities has been modeled in both circumferential and axial directions. To compute the bearing performance characteristics parameter, finite element formulation of governing Reynolds equation has been derived using Galerkin’s technique.

Findings

Based on the numerically simulated results, it has been observed that the three-dimensional irregularities enhance the value of minimum fluid film thickness (h̄min), lubricant flow (Q̄) and fluid film damping coefficients (C̄11,C̄22) approximately by order of magnitude of 24-26, 43-51 and 18-66 per cent, respectively, for the case of asymmetric slot entry configuration. Whereas, the values of fluid film stiffness coefficients (S̄11,S̄22) and threshold speed (ω̄th) reduces approximately by order of 1-6 and 0-3 per cent, respectively, for the case of symmetric slot entry configuration.

Originality/value

The present paper describes that the influence of three-dimensional irregularities on bearing surface on the performance of slot entry hybrid journal bearing is original in literature gaps. The numerically simulated results presented in this study are expected to be quite useful to the bearing designers.

Details

Industrial Lubrication and Tribology, vol. 70 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 30 June 2022

Arun Bangotra and Sanjay Sharma

This study aims to investigate the impact of surface waviness on the static performance parameters of hydrodynamic journal bearings operating with lubricants containing…

Abstract

Purpose

This study aims to investigate the impact of surface waviness on the static performance parameters of hydrodynamic journal bearings operating with lubricants containing copper oxide (CuO) and cerium oxide (CeO2) nanoparticles.

Design/methodology/approach

The static performance parameters of bearings with surface waviness and the addition of nanoparticles in lubricants were calculated using the nondimensional form of Reynolds equation and finite element method. Static performance parameters are calculated at different waviness numbers in the circumferential, axial and both directions at various wave amplitudes with variable viscosities of lubricants with nanoparticles using the viscosity equation forming a relationship between the relative viscosity, temperature and weight fraction of nanoparticles in lubricant developed from the experimental results.

Findings

The computed results indicate that the impact of waviness on the bearing surface enhances the load capacity, reduces friction coefficient, and is more effective in the circumferential direction than in the axial direction or in both directions. The addition of CuO and CeO2 to the lubricant enhanced its viscosity which further improved the steady-state parameters of the wave bearing.

Research limitations/implications

This study is based on a numerical technique, which has significant limitations, and the simulated results must be tested experimentally.

Practical implications

The current findings will be beneficial for designers to improve the performance of hydrodynamic journal bearings.

Originality/value

The calculated results demonstrate that the combined effect of the surface waviness on bearings and the addition of nanoparticles to lubricants can greatly increase the performance of hydrodynamic journal bearings.

Details

Industrial Lubrication and Tribology, vol. 74 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 20 June 2019

Sanjay Sharma, Gourav Jamwal and R.K. Awasthi

The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement…

Abstract

Purpose

The purpose of this paper is to provide the various steady state parameters of hydrodynamic journal bearings have been determined to get maximum performance enhancement ratio. For this, the bearings inner surface is textured with triangular shape with different texture depths and a number of textures in pressure increasing region. The textured region acts as a lubricant reservoir, which provides additional film-thickness and reduce friction. Therefore, enhance the overall performance of bearing.

Design/methodology/approach

In the present study, the effect of triangular shaped texture on the static performance characteristics of a hydrodynamic journal bearing has been studied. Different values of texture depths and a number of textures have been numerically simulated in pressure developing region. The static performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous Newtonian fluid. The performance enhancement ratio, which is the ratio of load carrying capacity (LCC) to the coefficient of friction (COF) has been calculated from results to finalized optimum design parameters.

Findings

The paper provides numerically obtained results indicate that surface texturing can improve bearing performance if the textured region is placed in the pressure increasing region. Moreover, surface texturing is the most effective at bearing performance enhancement when the bearing operates at lower eccentricity ratios and texture depth. The performance enhancement ratio, which is the ratio of LCC to the COF is found to be a maximum value of 2.198 at texture depth of 1.5, eccentricity ratio of 0.2 and the textured region located in the increasing pressure region.

Research limitations/implications

The present study is based on a numerical based research approach, which has its limitations. So, researchers are encouraged to investigate the same work experimentally.

Practical implications

The paper includes implications to be beneficial for designers for designing better hydrodynamic journal bearings.

Originality/value

For the triangular shaped texture, considered in the present study, the optimum values of texture depth and texture distribution region have also been determined. While designing, designers should focus on those values of texture depth, texture region and a number of textures, which give the maximum value of performance enhancement ratio, which represents maximum LCC at the lowest value of the COF.

Details

Industrial Lubrication and Tribology, vol. 71 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 5 February 2018

Vinod Yadav, Milind Kumar Sharma and Shailender Singh

In a developing economy like India, the contribution of small- and medium-sized enterprises (SMEs) to the national gross domestic product is significant. This sector…

Abstract

Purpose

In a developing economy like India, the contribution of small- and medium-sized enterprises (SMEs) to the national gross domestic product is significant. This sector creates immense employment opportunities and produces economic products and services. To survive in the globalized marked condition, it is essential for SMEs to be competitive on several fronts such as quality, cost, delivery, lead time, flexibility, etc. Hence, it is imperative for them to have a sound supplier base. Therefore, supplier selection problem (SSP) has a vital role to play in supply chain management of SMEs. The paper aims to discuss these issues.

Design/methodology/approach

However, SSP has now become a significant challenge to address due to the complexity, vagueness and various criteria involved in it. Recently, fuzzy Technique for Order Performance by Similarity to Ideal Solution method has been widely used to tackle such problems.

Findings

The present paper aims at developing an intelligent system for SSP, which can consider the multiple criteria and the uncertainty aspects in the decision process. A case study of a small-scale manufacturing company has been presented.

Practical implications

This study provides a guideline for SME sector to implement intelligent systems for supplier selection decision-making problems. Case application concludes that this model improves firm’s decision making and suppliers’ performance.

Originality/value

The proposed intelligent model can provide the guidelines and directions for the decision makers to effectively choose suppliers in the current competitive environment. And it also provides an opportunity for supplier improvement.

Details

Benchmarking: An International Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1463-5771

Keywords

Article
Publication date: 10 December 2019

Muhammed Adem, Sadik J.A., Admasu Worku and Satheesh Neela

This paper aims to optimize feed moisture contents, barrel temperatures, blending ratios of maize and lupine for processing of protein-rich best quality extruded product…

Abstract

Purpose

This paper aims to optimize feed moisture contents, barrel temperatures, blending ratios of maize and lupine for processing of protein-rich best quality extruded product using a twin-screw extruder.

Design/methodology/approach

A three-factor three-level response surface methodology by Box-Behnken Design was applied to evaluate the effect of selected processing conditions of blending ratios of lupine (10-20 per cent), barrel temperatures (120°C-150°C) and feed moisture content (14-18 per cent) on functional, nutritional and sensory characteristics of produced snack food.

Findings

The results of functional properties such as radial expansion ratio, bulk density, water absorption index, water solubility index observed as 0.71-1.2, 0.33-0.92 g/cc, 4.4-6.4 per cent and 10.2-15.1 per cent, respectively. The snack food showed the moisture 5.6-7.2 per cent, protein 8.1-18.1 per cent, fiber 1.6-2.7 per cent, ash 1.6-2.2 per cent and carbohydrate 64.8-81.4 per cent. The independent variables (lupine blending ratio, barrel temperature and feed moisture content) posed significant effects on expansion ration (p = 0.0030), bulk density (p = 0.0026), water absorption index (p = 0.0075) and water-solubility index (p = 0.0116). Higher blending ratio of lupine was increase in the bulk density and water solubility index, but decrease in expansion ratio and water absorption index of snack food. Higher feed moisture content was led to a reduction in expansion ratio and water-soluble index of snack food. Whereas, higher feed moisture contents was lead to rise in bulk density and water absorption index. Fiber (p = 0.0145), ash (p = 0.0343) and carbohydrate (p = 0.0001) contents were significantly depended on blending ratio. Blending of lupine 15.06 per cent, barrel temperature of 150 °C and feed moisture content of 14.0 per cent produced the snack food with desirability value of 72.8 per cent.

Originality/value

Protein malnutrition is one of the major problems in child development in under developed countries including Ethiopia. Maize is a top producer in the country but least appreciated for cost. Lupine is one of the undervalued produce consumed in Ethiopia after boiling. Still data on the utilization of maize and lupine in the extruded snack preparation was very limited. Optimization of moisture and barrel temperatures for this snack was not reported clearly yet.

Details

Nutrition & Food Science , vol. 50 no. 5
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 1 June 1994

Chandra Bhushan Sharma

This paper suggests a standard format for creating hypermedia software. Teachers and students of literature have taken up the use of hypermedia technology enthusiastically…

Abstract

This paper suggests a standard format for creating hypermedia software. Teachers and students of literature have taken up the use of hypermedia technology enthusiastically and so we are rapidly arriving at a situation where a mushrooming of software for language and literature teaching will be faced. We will arrive much sooner at a situation where searching for an appropriate software would be as difficult as finding an appropriate article today. Technology is expected to optimise information to maximise knowledge: the confusion created by Gutenburg's invention is because duplication cannot be avoided. The suggested format is based on the major pillars of literary criticism — author centred, text centred and reader centred—and develops from the word to the work level. The findings have been demonstrated in the form of Technocriticism, a hypermedia program created on HyperCard.

Details

The Electronic Library, vol. 12 no. 6
Type: Research Article
ISSN: 0264-0473

Article
Publication date: 28 December 2021

Kushagra Kulshreshtha, Gunjan Sharma and Naval Bajpai

Since the inception of the conjoint analysis technique in the year 1971, papers addressing the epistemological aspects of conjoint analysis are scant. Hence, this paper…

Abstract

Purpose

Since the inception of the conjoint analysis technique in the year 1971, papers addressing the epistemological aspects of conjoint analysis are scant. Hence, this paper attempts to address the vacuum of qualitative discourse addressing the epistemological and methodological aspects of conjoint analysis including different issues, challenges, probable solutions, limitations and future direction of conjoint analysis in the recent decade.

Design/methodology/approach

For exploring the methodological and epistemological aspects of conjoint analysis, the seminal papers on conjoint analysis were reviewed. Moreover, the authors' experience for the state-of-art review was also taken into consideration.

Findings

The findings suggest that conjoint analysis that roots back since 1971 has not seen much exploration in Asian regions and is mainly used for new product development in the field of marketing or allied areas. Moreover, the reliability and validity of conjoint analysis is always a matter of concern for the researchers that hinders this technique's wider adaptability. Thus, the paper presents some probable solutions to address the focal issues useful for improved reliability and validity of the conjoint analysis technique.

Research limitations/implications

This paper attempts to familiarize the researchers with epistemological and methodological aspects of conjoint analysis with certain solutions to evolve beyond existing conjoint analysis dimensions in terms of improved validity, reliability, epistemological and methodological aspects of conjoint analysis (CA). Moreover, it acts as a call for research in different research domains, especially in the Asian continent.

Originality/value

There exist certain seminal research papers on epistemological aspects of conjoint analysis. However, there is a dearth of such attempt in the recent decade addressing the application issues of conjoint analysis incorporating the recent issues as well. Therefore, this paper is an attempt to usher the future researcher to understand the methodological aspects of conjoint analysis. It may prevent them from violating the basic assumptions and methodological threshold. This research technique is preferred equally by academicians and practitioners, thus making it imperative to have clarity beforehand for improved research rigor.

Details

International Journal of Quality & Reliability Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 27 August 2019

Bijuan Yan, Huijun Liang, Minjie Jin, Zhanlong Li and Yong Song

In the vibration reduction field, constrained stand-off layer damping cylindrical shell plays an important role. However, due to the lack of accurate analysis of its…

Abstract

Purpose

In the vibration reduction field, constrained stand-off layer damping cylindrical shell plays an important role. However, due to the lack of accurate analysis of its damping characteristics, this hinders its further research and application. Therefore, the purpose of this paper is concerned with an accurate solution for the vibration-damping characteristics of a constrained stand-off-layer damping cylindrical shell (CSDCS) under various classical boundary conditions and conducts a further analysis.

Design/methodology/approach

Based on the Rayleigh–Ritz method and the Hamilton principle, a dynamic model of CSDCS is established. Then the loss factor and the frequency of CSDCS are obtained. The correctness and convergence behavior of the present model are verified by comparing the calculation results with the literature. By using for various classical boundary conditions without any special modifications in the solution procedure, the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries are discussed.

Findings

The Rayleigh–Ritz method is effective in handling the problem of CSDCS with different boundaries and an accurate solution is obtained. The boundary conditions have an important influence on the vibration and damping behavior of the CSDCS.

Originality/value

Based on the Rayleigh–Ritz method and Hamilton principle, a dynamic model of CSDCS is established for the first time, and then the loss factor and frequency of CSDCS are obtained. In addition, the effectiveness of adding the stand-off layer between the base shell and the viscoelastic layer is confirmed by discussing the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries.

Details

Engineering Computations, vol. 37 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 24 July 2019

Gourav Jamwal, Sanjay Sharma and R.K. Awasthi

This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner surface is textured with…

Abstract

Purpose

This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner surface is textured with chevron-shaped textures with different texture depths and number of textures in different regions/locations.

Design/methodology/approach

In the present study, the effect of chevron-shaped texture having different values of texture depths, locations and number of textures has been numerically simulated. The dynamic performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous and Newtonian fluid.

Findings

The obtained results indicate that the bearing stability can be improved with the help of surface texture. Among all the investigated texture locations, the maximum increase in stability threshold speed is observed for fully textured distribution. Moreover, for the chevron-shaped texture considered in the present study, the optimum values of texture depth and number of textures have also been determined for maximum bearing stability.

Practical implications

While designing, designers should focus on those optimum values of texture depth, texture location and number of textures which lead to maximum enhancement in bearing stability.

Originality/value

This study is useful in the appropriate selection of chevron-shaped texture parameters on bearing surface for the maximum bearing stability.

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