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Book part
Publication date: 8 May 2003

Yung- Lung Lee and Kuang- Yih Yeh

Street closure following an earthquake makes life-saving and rescue work more difficult, especially in congested urban areas. After the great Chi-chi earthquake, recovery and…

Abstract

Street closure following an earthquake makes life-saving and rescue work more difficult, especially in congested urban areas. After the great Chi-chi earthquake, recovery and reconstruction work became necessary. In particular, we have to investigate the street network damages and other effects. Considering the road improvement plan, not only malfunction recovery but also a comprehensive evaluation should be considered in future urban planning. The reliable street network against earthquakes is the central concern of this survey.

This study attempts to implement a case study survey of damaged areas, and analyze the effecting factors on street closure. We also try to evaluate the road function against earthquake integrated with the street-damaged characteristics. Using a discriminant model of street closure, some design guidelines for future transportation planning decisions are proposed.

Nan-tou City network has 365 links and 66.6% of them are less than 6 meters in width. Ton-shi Town network has 248 links and 35% of them are less than 6 meters in width. The same definition of street closure (impassable by vehicles) of ‘street width less than 4 meters’ was applied to these two case studies. This research considered several street network alternatives, the inaccessible nodes for all alternatives and analysis in order to determine a more reliable street network for increased safety. Results of both surveyed areas suggest that when we decrease the interval distance of the 8-M street, the percentage of the differences of inaccessible nodes will also decrease.

The Chi-chi earthquake did great harm in the disaster area. Fortunately we find the street damages of our surveying area were not too severe to maintain their functions in times of earthquake. However, it is still meaningful for a transport planner to evaluate the reliability of residential streets because the main target of planning a residential street network is to restrain through-traffic in this area to ensure safe and comfortable conditions for pedestrians while meeting residential access requirements.

Details

The Network Reliability of Transport
Type: Book
ISBN: 978-0-08-044109-2

Content available
Book part
Publication date: 8 May 2003

Abstract

Details

The Network Reliability of Transport
Type: Book
ISBN: 978-0-08-044109-2

Article
Publication date: 26 September 2023

Thameem Hayath Basha, Sivaraj Ramachandran and Bongsoo Jang

The need for precise synthesis of customized designs has resulted in the development of advanced coating processes for modern nanomaterials. Achieving accuracy in these processes…

Abstract

Purpose

The need for precise synthesis of customized designs has resulted in the development of advanced coating processes for modern nanomaterials. Achieving accuracy in these processes requires a deep understanding of thermophysical behavior, rheology and complex chemical reactions. The manufacturing flow processes for these coatings are intricate and involve heat and mass transfer phenomena. Magnetic nanoparticles are being used to create intelligent coatings that can be externally manipulated, making them highly desirable. In this study, a Keller box calculation is used to investigate the flow of a coating nanofluid containing a viscoelastic polymer over a circular cylinder.

Design/methodology/approach

The rheology of the coating polymer nanofluid is described using the viscoelastic model, while the effects of nanoscale are accounted for by using Buongiorno’s two-component model. The nonlinear PDEs are transformed into dimensionless PDEs via a nonsimilar transformation. The dimensionless PDEs are then solved using the Keller box method.

Findings

The transport phenomena are analyzed through a comprehensive parametric study that investigates the effects of various emerging parameters, including thermal radiation, Biot number, Eckert number, Brownian motion, magnetic field and thermophoresis. The results of the numerical analysis, such as the physical variables and flow field, are presented graphically. The momentum boundary layer thickness of the viscoelastic polymer nanofluid decreases as fluid parameter increases. An increase in mixed convection parameter leads to a rise in the Nusselt number. The enhancement of the Brinkman number and Biot number results in an increase in the total entropy generation of the viscoelastic polymer nanofluid.

Practical implications

Intelligent materials rely heavily on the critical characteristic of viscoelasticity, which displays both viscous and elastic effects. Viscoelastic models provide a comprehensive framework for capturing a range of polymeric characteristics, such as stress relaxation, retardation, stretching and molecular reorientation. Consequently, they are a valuable tool in smart coating technologies, as well as in various applications like supercapacitor electrodes, solar collector receivers and power generation. This study has practical applications in the field of coating engineering components that use smart magnetic nanofluids. The results of this research can be used to analyze the dimensions of velocity profiles, heat and mass transfer, which are important factors in coating engineering. The study is a valuable contribution to the literature because it takes into account Joule heating, nonlinear convection and viscous dissipation effects, which have a significant impact on the thermofluid transport characteristics of the coating.

Originality/value

The momentum boundary layer thickness of the viscoelastic polymer nanofluid decreases as the fluid parameter increases. An increase in the mixed convection parameter leads to a rise in the Nusselt number. The enhancement of the Brinkman number and Biot number results in an increase in the total entropy generation of the viscoelastic polymer nanofluid. Increasing the strength of the magnetic field promotes an increase in the density of the streamlines. An increase in the mixed convection parameter results in a decrease in the isotherms and isoconcentration.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 2
Type: Research Article
ISSN: 0961-5539

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