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Article
Publication date: 24 November 2021

Mohammed S. Ismail, Mohamed R. Berber, Ziyad A. Alrowaili and Mohamed Pourkashanian

This paper aims to numerically solve fully developed laminar flow in trapezoidal ducts with rounded corners which result following forming processes.

Abstract

Purpose

This paper aims to numerically solve fully developed laminar flow in trapezoidal ducts with rounded corners which result following forming processes.

Design/methodology/approach

A two-dimensional model for a trapezoidal duct with rounded corners is developed and conservation of momentum equation is solved. The flow is assumed to be steady, fully developed, laminar, isothermal and incompressible. The key flow characteristics including the Poiseuille number and the incremental pressure drop have been computed and tabulated for a wide range of: sidewall angle (θ); the ratio of the height of the duct to its smaller base (α); and the ratio of the fillet radius of the duct to its smaller base (β).

Findings

The results show that Poiseuille number decreases, and all the other dimensionless numbers increase with increasing the radii of the fillets of the duct; these effects were found to amplify with decreasing duct heights or increasing sidewall angles. The maximum axial velocity was shown to increase with increasing the radii of the fillets of the duct. For normally used ducts in hydrogen fuel cells, the impact of rounded corners cannot be overlooked for very low channel heights or very high sidewall angles.

Practical implications

The data generated in this study are highly valuable for engineers interested in estimating pressure drops in rounded trapezoidal ducts; these ducts have been increasingly used in hydrogen fuel cells where flow channels are stamped on thin metallic sheets.

Originality/value

Fully developed laminar flow in trapezoidal ducts with four rounded corners has been solved for the first time, allowing for more accurate estimation of pressure drop.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 18 January 2021

Mingyu Zhang, Jing Wang, Peiran Yang, Yi Liu, Zhaohua Shang and Longjie Dai

This study aims to investigate the influence of geometry of bush-pin pair from a perspective of optimal lubrication through a thermal elastohydrodynamic lubrication model…

Abstract

Purpose

This study aims to investigate the influence of geometry of bush-pin pair from a perspective of optimal lubrication through a thermal elastohydrodynamic lubrication model for finite line contact.

Design/methodology/approach

A constitutive equation: Ree-Eyring fluid is used in the calculations. The real chain sizes, i.e. equivalent radius of curvature, bush length, length of the rounded corner area and rounded corner radius, are jointed investigated. Moreover, the effects of the length of the rounded corner area and the radius of rounded corner are investigated.

Findings

It is found that the current standard of the chain might not consider the importance of lubrication, and the lubrication state can be improved effectively by choosing an optimal radius of rounded corner and the length of the corner area.

Originality/value

By optimally selecting sizes, the occurrence of high pressure, high temperature rise and near zero film thickness at the ends of bush, especially under heavier load, can be effectively avoided.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0031/

Details

Industrial Lubrication and Tribology, vol. 73 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 13 September 2011

Michael F. Walsh, Karen Page Winterich and Vikas Mittal

This research aims to explore how consumer responses to logo redesign (from angular to rounded) are contingent on brand commitment and self‐construal. The authors aim to…

4490

Abstract

Purpose

This research aims to explore how consumer responses to logo redesign (from angular to rounded) are contingent on brand commitment and self‐construal. The authors aim to explore two issues. First, what is the role of brand commitment on response to logo redesign and underlying brand attitude? Second, how does situational accessible self‐construal influence brand commitment in situations like this?

Design/methodology/approach

This research uses two field experiments; one using the general public via mall intercepts and the second with undergraduate college students.

Findings

In two studies the authors show that brand commitment negatively influences evaluation of inconsistent information (i.e. rounded logo), and this negative logo evaluation mediates the impact on brand attitude. They also find that motivated reasoning may be at play showing that when faced with inconsistent information brand commitment not only increases thought generation but, specifically, negative thoughts about the logo. Study 2, using more realistic stimuli shows that the deleterious effect of inconsistent information (i.e. new logo) is attenuated when the inconsistent information – i.e. rounded logo – is congruent with the consumers' self‐construal (i.e. interdependent self‐construal).

Research limitations/implications

The authors advance the literature on self‐construal in advertising by identifying that self‐construal framing of ads may impact consumer response regardless of individual differences in self‐construal. They build on the work of Tsai who examined the effects of consumer characteristics such as product involvement and product knowledge in light of self‐construal differences on ad evaluation and purchase intentions.

Practical implications:

The findings presented here suggest that consumers' responses to atypical brand information may be dependent on their level of brand commitment. This research shows that logo redesign in particular, and introduction of inconsistent information in general is a process that should be carefully managed. The second experiment shows that the independent message frame is the preferred approach for multi cultural/global marketers. In primarily independent cultures, one should target highly committed customers. In primarily interdependent cultures one can target both strongly and weakly committed consumers. These findings can help companies entering international markets or dealing with global brands. Beyond advertising, this research has application to other forms of brand aesthetics including packaging and web site design.

Originality/value

This study is the first to show that self‐construal framing can act as a boundary condition on the role that consumer commitment plays in shaping ad evaluations and purchase intentions regardless of chronic self‐construal.

Details

Journal of Consumer Marketing, vol. 28 no. 6
Type: Research Article
ISSN: 0736-3761

Keywords

Article
Publication date: 7 October 2021

Iuri Yudi Furukita Baptista, Fabiana Carvalho, Priscilla Efraim, Paulo Túlio de Souza Silveira and Jorge Behrens

Research on cross-modal sensory interactions has shown that visual aspects of food can influence consumer's expectation and perception of taste, mouthfeel and liking. This…

Abstract

Purpose

Research on cross-modal sensory interactions has shown that visual aspects of food can influence consumer's expectation and perception of taste, mouthfeel and liking. This paper aims to investigate the effects of a rounded (“bouba”) and a squared (“kiki”) shape on expected and perceived sweetness, bitterness, creaminess and liking of chocolates.

Design/methodology/approach

Brazilian consumers (N = 230) divided into two groups of 115 individuals each evaluated five chocolates containing 30, 40, 50, 60 and 70% of cocoa. One of the groups evaluated all formulations in the rounded shape and the other in the squared shape. Results were analysed with mixed multivariate analysis of variance (mixed-MANOVA) between shapes, repeated-measures MANOVA between pre- and post-tasting and Pearson's correlation analysis was performed between liking ratings and sweetness, bitterness and creaminess confirmation/disconfirmation.

Findings

The study found significant effects (p < 0.05) of shape on expected and perceived creaminess but not on other attributes; of cocoa percentage (30, 40, 50, 60 and 70%) on all four attributes; and time (pre- and post-tasting) on sweetness, bitterness and liking but not creaminess. Finally, it found significant negative correlations between the creaminess difference indices and the liking ratings for the 30, 50 and 60% chocolates.

Originality/value

This study reports that consumers may expect and perceive chocolates as creamier in a rounded shape than in an angular shape and that if the expectation of creaminess is not confirmed by sensory perception, acceptability may be negatively affected.

Details

British Food Journal, vol. 124 no. 5
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 4 January 2016

Sajjad Miran and Chang Hyun Sohn

– The purpose of this paper is to focus on the variation of wake structures and aerodynamic forces with changes in the cylinder corner radius and orientation.

Abstract

Purpose

The purpose of this paper is to focus on the variation of wake structures and aerodynamic forces with changes in the cylinder corner radius and orientation.

Design/methodology/approach

Numerical simulations were performed for flow past a square cylinder with different corner radii placed at an angle to the incoming flow. In the present study, the rounded corner ratio R/D=0 (square cylinder), 0.1, 0.2, 0.3, and 0.4 (where R is the corner radius and D is the characteristic dimension of the body) and the angle of incidence α in the range of 0°-45° were considered.

Findings

The numerical model was validated by comparing the present results with results in the available literature, and they were found to be in good agreement. The critical incidence angle for the rounded corner cylinder – corresponding to the minimum mean drag coefficient (C D ), the minimum root mean square value of the lift coefficient C L,RMS), and the maximum Strouhal number – shifted to a lower incidence angle compared with the sharp corner square cylinder. The minimum drag and lift coefficient at R/D=0 were observed for the critical incidence angle αcri=12°, whereas for R/D=0.1-0.4, the minimum drag and lift coefficient were found to be within the range of 5°-10° for α.

Originality/value

The presented results shows the importance of the incidence angle and rounded corners of the square cylinder for reduction of aerodynamic forces. The two parameters support the shear layer flow reattachment on the lateral surface of the cylinder, have a strong correlation with the reduction of the wake width, and hence reduced the values of C D and C L .

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 July 2017

Jian Liu, Gongnan Xie, Bengt Ake Sunden, Lei Wang and Martin Andersson

The purpose of this paper is to augment heat transfer rates of traditional rib-elements with minimal pressure drop penalties.

Abstract

Purpose

The purpose of this paper is to augment heat transfer rates of traditional rib-elements with minimal pressure drop penalties.

Design/methodology/approach

The novel geometries in the present research are conventional cylindrical ribs with rounded transitions to the adjacent flat surfaces and with modifications at their bases. All turbulent fluid flow and heat transfer results are presented using computation fluid dynamics with a validated v2f turbulence closure model. Turbulent flow characteristics and heat transfer performances in square channels with improved ribbed structures are numerically analyzed in this research work.

Findings

Based on the results, it is found that rounded transition cylindrical ribs have a large advantage over the conventional ribs in both enhancing heat transfer and reducing pressure loss penalty. In addition, cylindrical ribs increase the flow impingement at the upstream of the ribs, which will effectively increase the high heat transfer areas. The design of rounded transition cylindrical ribs and grooves will be an effective way to improve heat transfer enhancement and overall thermal performance of internal channels within blade cooling.

Originality/value

The novel geometries in this research are conventional cylindrical ribs with rounded transitions to the adjacent flat surfaces and with modifications at their bases. The combination of cylindrical ribs and grooves to manipulate the turbulent flow.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 5 May 2015

Sajjad Miran and Chang Hyun Sohn

– The purpose of this paper is to numerically investigate the influence of corner radius on flow past a square cylinder at a Reynolds number 500.

Abstract

Purpose

The purpose of this paper is to numerically investigate the influence of corner radius on flow past a square cylinder at a Reynolds number 500.

Design/methodology/approach

Six models were studied, for R/D=0 (square cylinder), 0.1, 0.2, 0.3, 0.4, and 0.5 (circular cylinder), where R is the corner radius and D is the characteristic dimension of the body. The transient two-dimensional (2D) laminar and large eddy simulations (LES) models were employed using finite volume code. The Strouhal number, mean drag coefficient (CD), and root mean square (RMS) value of lift coefficient (CL,RMS), for different R/D values, were computed and compared with experimental and other numerical results.

Findings

The computational results showed good agreement with previously published results for a Reynolds number, Re=500. It was found that the corner effect on a square cylinder greatly influences the flow characteristics around the cylinder. Results indicate that, as the corner radius ratio, R/D, increases, the Strouhal number increases rapidly for R/D=0-0.2, and then gradually rises between R/D=0.2 and 0.5. The minimum values of the mean drag coefficient and the RMS value of lift coefficient were found around R/D=0.2, which is verified by the time averaged streamwise velocity deficit profile.

Originality/value

On the basis of the numerical results, it is concluded that rounded corners on a square cylinder are useful in reducing the drag and lift forces generated behind a cylinder. Finally, it is suggested that with a rounded corner ratio of around R/D=0.2, the drag and oscillation of the cylinder can be greatly reduced, as compared to circular and square cylinders.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 25 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 17 August 2020

Juan Sebastian Gomez Bonilla, Maximilian Alexander Dechet, Jochen Schmidt, Wolfgang Peukert and Andreas Bück

The purpose of this paper is to investigate the effect of different heating approaches during thermal rounding of polymer powders on powder bulk properties such as…

Abstract

Purpose

The purpose of this paper is to investigate the effect of different heating approaches during thermal rounding of polymer powders on powder bulk properties such as particle size, shape and flowability, as well as on the yield of process.

Design/methodology/approach

This study focuses on the rounding of commercial high-density polyethylene polymer particles in two different downer reactor designs using heated walls (indirect heating) and preheated carrier gas (direct heating). Powder bulk properties of the product obtained from both designs are characterized and compared.

Findings

Particle rounding with direct heating leads to a considerable increase in process yield and a reduction in powder agglomeration compared to the design with indirect heating. This subsequently leads to higher powder flowability. In terms of shape, indirect heating yields not only particles with higher sphericity but also entails substantial agglomeration of the rounded particles.

Originality/value

Shape modification via thermal rounding is the decisive step for the success of a top-down process chain for selective laser sintering powders with excellent flowability, starting with polymer particles from comminution. This report provides new information on the influence of the heating mode (direct/indirect) on the performance of the rounding process and particle properties.

Details

Rapid Prototyping Journal, vol. 26 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

Open Access
Article
Publication date: 19 November 2020

Clarence Goh

Prior studies have documented the phenomenon of rounding of analysts' earnings per share (EPS) forecasts in the USA. From the outset, it is unclear if analysts following…

Abstract

Purpose

Prior studies have documented the phenomenon of rounding of analysts' earnings per share (EPS) forecasts in the USA. From the outset, it is unclear if analysts following Singapore firms also similarly engage in the rounding of their EPS forecasts. This study aims to investigate the extent to which analysts engage in rounding of EPS forecasts of firms listed on the Singapore Exchange.

Design/methodology/approach

The author conducted his analysis on a sample of analyst EPS forecasts of companies listed on the Singapore Stock Exchange, downloaded from the International Brokers Estimate System (I/B/E/S). This sample consists of 24,219 annual EPS forecasts announced from June 2011 to September 2019. These forecasts were made for 285 unique firms by 48 unique analysts.

Findings

The author finds that there is substantial rounding of EPS forecasts, with 9.59% of EPS forecasts examined ending in five- or ten-cent intervals. In supplementary analysis, the author further finds that the level of rounding was comparable across two periods under examination, from 2011 to 2015 and from 2016 to 2019. The author also finds that there was substantial rounding even for forecasts of relatively large magnitudes (i.e. US$1.00 and above).

Originality/value

This study is the first to examine the rounding of analysts' EPS forecasts of Singapore firms. It extends the literature on analyst EPS forecasts and highlights how the phenomenon of rounding of analyst EPS forecasts of US firms extends to Singapore.

Details

Asian Journal of Accounting Research, vol. 6 no. 1
Type: Research Article
ISSN: 2443-4175

Keywords

Article
Publication date: 1 February 1992

M. BERELOWITZ and P. BAR‐YOSEPH

The numerical investigation into the stirring induced by an alternating magnetic field, applied in the axial direction of a closed axisymmetric container of conducting…

Abstract

The numerical investigation into the stirring induced by an alternating magnetic field, applied in the axial direction of a closed axisymmetric container of conducting fluid, is presented. The interaction between the azimuthal current and magnetic field results in Lorentz forces in the meridional plane which induce the fluid flow. The magnetic Reynolds number is assumed to be smaller than the frequency magnetic Reynolds number. The electromagnetic equations are thus decoupled from the fluid flow equations. The electromagnetic field is first solved, and the body forces determined from this are introduced into the Navier‐Stokes equations. With the flow field known, the quality of mixing is determined by solving the tracer dispersion equation. The finite element method based on a Galerkin formulation is used for the solution of the equations. Three cases are examined: a finite length cylinder, a finite length cylinder with rounded corners and a sphere. In general, two vortices are formed, the equatorial vortex closest to the equator and the end vortex at the closed end. Results show that the introduction of the rounded corner increases the size and strength of the end vortex with the opposite effect on the equatorial vortex. Of the three frequency magnetic Reynolds numbers considered (Rw=30, 100 and 800), Rw=100 results in the best mixing for all cases. Rounding the corner of the cylinder only results in a definite improvement of mixing at Rw=800. The sphere results in even better mixing than this at Rw=800, but is worse than the first two geometries for Rw=30 and 100 when the interaction parameter is large.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 2 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of over 51000