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Article
Publication date: 5 February 2018

Siddharth Kulkarni, Craig Chapman, Hanifa Shah, Erika Anneli Parn and David John Edwards

This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry.

Abstract

Purpose

This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry.

Design/methodology/approach

The paper provides an insight of the tidal turbine blade design and need for renewable energy sources to generate electricity through clean energy sources and less CO2 emission. The ocean environment, along with hydrodynamic design principles of a horizontal axis tidal turbine blade, is described, including theoretical maximum efficiency, blade element momentum theory and non-dimensional forces acting on tidal turbine blades.

Findings

This review gives an overview of fish locomotion identifying the attributes of the swimming like lift-based thrust propulsion, the locomotion driving factors: dorsal fins, caudal fins in propulsion, which enable the fish to be efficient even at low tidal velocities.

Originality/value

Finally, after understanding the phenomenon of caudal fin propulsion and its relationship with tidal turbine blade hydrodynamics, this review focuses on the implications of bio-mimicking a curved caudal fin to design an efficient horizontal axis tidal turbine.

Details

Journal of Engineering, Design and Technology, vol. 16 no. 1
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 14 May 2018

Siddharth Suhas Kulkarni, Craig Chapman, Hanifa Shah and David John Edwards

The purpose of this paper is to conduct a comparative analysis between a straight blade (SB) and a curved caudal-fin tidal turbine blade (CB) and to examine the aspects…

Abstract

Purpose

The purpose of this paper is to conduct a comparative analysis between a straight blade (SB) and a curved caudal-fin tidal turbine blade (CB) and to examine the aspects relating to geometry, turbulence modelling, non-dimensional forces lift and power coefficients.

Design/methodology/approach

The comparison utilises results obtained from a default horizontal axis tidal turbine with turbine models available from the literature. A computational design method was then developed and implemented for “horizontal axis tidal turbine blade”. Computational fluid dynamics (CFD) results for the blade design are presented in terms of lift coefficient distribution at mid-height blades, power coefficients and blade surface pressure distributions. Moving the CB back towards the SB ensures that the total blade height stays constant for all geometries. A 3D mesh independency study of a “straight blade horizontal axis tidal turbine blade” modelled using CFD was carried out. The grid convergence study was produced by employing two turbulence models, the standard k-ε model and shear stress transport (SST) in ANSYS CFX. Three parameters were investigated: mesh resolution, turbulence model, and power coefficient in the initial CFD, analysis.

Findings

It was found that the mesh resolution and the turbulence model affect the power coefficient results. The power coefficients obtained from the standard k-ε model are 15 to 20 per cent lower than the accuracy of the SST model. Further analysis was performed on both the designed blades using ANSYS CFX and SST turbulence model. The variation in pressure distributions yields to the varying lift coefficient distribution across blade spans. The lift coefficient reached its peak between 0.75 and 0.8 of the blade span where the total lift accelerates with increasing pressure before drastically dropping down at 0.9 onwards due to the escalating rotational velocity of the blades.

Originality/value

The work presents a computational design methodological approach that is entirely original. While this numerical method has proven to be accurate and robust for many traditional tidal turbines, it has now been verified further for CB tidal turbines.

Details

International Journal of Building Pathology and Adaptation, vol. 36 no. 2
Type: Research Article
ISSN: 2398-4708

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Article
Publication date: 4 February 2019

Siddharth Kulkarni, David John Edwards, Craig Chapman, M. Reza Hosseini and De-Graft Owusu-Manu

Road passenger transportation faces a global challenge of reducing environmental pollution and greenhouse gas emissions because of the vehicle weight increases needed to…

Abstract

Purpose

Road passenger transportation faces a global challenge of reducing environmental pollution and greenhouse gas emissions because of the vehicle weight increases needed to enhance passenger safety and comfort. This paper aims to present a preliminary mechanical design evaluation of the Wikispeed Car (with a focus on body bending, body torsion and body crash) to assess light-weighting implications and improve the vehicle’s environmental performance without compromising safety.

Design/methodology/approach

For this research, finite element analysis (FEA) was performed to examine the Wikispeed chassis for light-weighting opportunities in three key aspects of the vehicle’s design, namely, for body bending the rockers (or longitudinal tubes), for body torsion (again on the rockers but also the chassis as a whole) and for crash safety – on the frontal crash structure. A two-phase approach was adopted, namely, in phase one, a 3D CAD geometry was generated and in phase, two FEA was generated. The combination of analysis results was used to develop the virtual model using FEA tools, and the model was updated based on the correlation process.

Findings

The research revealed that changing the specified material Aluminium Alloy 6061-T651 to Magnesium EN-MB10020 allows vehicle mass to be reduced by an estimated 110 kg, thus producing a concomitant 10 per cent improvement in fuel economy. The initial results imply that the current beam design made from magnesium would perform worst during a crash as the force required to buckle the beam is the lowest (between 95.2 kN and 134 kN). Steel has the largest bandwidth of force required for buckling and also requires the largest force for buckling (between 317 kN and 540 kN).

Originality/value

This is the first study of its kind to compare and contrast between material substitution and its impact upon Wikispeed car safety and performance.

Details

Journal of Engineering, Design and Technology, vol. 17 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

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Article
Publication date: 4 December 2018

Siddharth Kulkarni, David John Edwards, Erika Anneli Parn, Craig Chapman, Clinton Ohis Aigbavboa and Richard Cornish

Vehicle weight reduction represents a viable means of meeting tougher regulatory requirements designed to reduce fuel consumption and control greenhouse gas emissions…

Abstract

Purpose

Vehicle weight reduction represents a viable means of meeting tougher regulatory requirements designed to reduce fuel consumption and control greenhouse gas emissions. This paper aims to present an empirical and comparative analysis of lightweight magnesium materials used to replace conventional steel in passenger vehicles with internal combustion engines. The very low density of magnesium makes it a viable material for lightweighting given that it is lighter than aluminium by one-third and steel by three-fourth.

Design/methodology/approach

A structural evaluation case study of the “open access” Wikispeed car was undertaken. This included an assessment of material design characteristics such as bending stiffness, torsional stiffness and crashworthiness to evaluate whether magnesium provides a better alternative to the current usage of aluminium in the automotive industry.

Findings

The Wikispeed car had an issue with the rocker beam width/thickness (b/t) ratio, indicating failure in yield instead of buckling. By changing the specified material, Aluminium Alloy 6061-T651 to Magnesium EN-MB10020, it was revealed that vehicle mass could be reduced by an estimated 110 kg, in turn improving the fuel economy by 10 per cent. This, however, would require mechanical performance compromise unless the current design is modified.

Originality/value

This is the first time that a comparative analysis of material substitution has been made on the Wikispeed car. The results of such work will assist in the lowering of harmful greenhouse gas emissions and simultaneously augment fuel economy.

Details

Journal of Engineering, Design and Technology, vol. 16 no. 6
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 1 January 2013

Mukta Kulkarni and Siddharth Nithyanand

Past research has largely portrayed job choice as a relatively rational and goal‐directed behavior where applicants make decisions contingent on organizational recruitment…

Abstract

Purpose

Past research has largely portrayed job choice as a relatively rational and goal‐directed behavior where applicants make decisions contingent on organizational recruitment activities, or evaluations of job and organizational attributes. Research now informs us that job choice decisions may also be based on social comparisons and social influence. The purpose of this paper is to add to this body of knowledge by examining reasons why social influence is a key factor in job choice decisions of relatively young job seekers.

Design/methodology/approach

The study is based on in‐depth interview data from graduating seniors at an elite business school in India.

Findings

Respondents did not see themselves as acting based on social influence as much as they perceived others around them to be. Reasons they noted for others’ socially influenced job choice decisions were: peers and seniors are seen as more accessible and trustworthy than organizations; organizations do not share all and/or objective data, driving job seekers to other sources; job seekers are clueless and hence follow a “smart” herd; and job seekers make decisions for social status signaling. Respondents pointed to socially influenced job choices as being rational behaviors under certain conditions.

Research limitations/implications

Generalizability of findings may be limited to young job seekers or to the Indian context, and the authors encourage replication. The authors also acknowledge the importance of individual difference variables in job choice decisions, a factor not considered in the present research.

Practical implications

Given that job seekers rally around others’ notion of an attractive job or an organization, the paper outlines several implications for managerial practice.

Originality/value

This study, in a yet unexamined cultural context, points to the simultaneous and combined importance of normative and informational social determinants of job choice, bias blind spots in one's own job choice perceptions and decisions, gender specific socialization influences on job choices, and the notion of job fit in terms of fitment with expectations of important reference groups.

Details

Employee Relations, vol. 35 no. 2
Type: Research Article
ISSN: 0142-5455

Keywords

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