Journal ArticleDOI
Laminarization and turbulentization in a pulsatile pipe flow
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In this paper, a fluid-flow model which automatically determines the flow regime was used to analyze a timewise-periodic pipe flow, and numerical simulation was employed to implement the model.Abstract:
A fluid-flow model which automatically determines the flow regime was used to analyze a timewise-periodic pipe flow. Numerical simulation was employed to implement the model. The range of the instantaneous Reynolds number gave rise to four distinct flow regimes: laminarizing, fully laminar, turbulentizing, and fully turbulent. The period of the imposed harmonic oscillations was varied over a very wide range, and the magnitude of the oscillations was of the same order as that of the steady flow on which the oscillations were superimposed. A large-period limit at which the flow is quasi-steady was identified. The predicted quasi-steady fully developed friction factor for each regime was found to be in excellent agreement with steady-state results applied instantaneously. A metric in the form of the ratio of the turbulence production to turbulence destruction was used to exhibit the turbulence characteristics of each of the four flow regimes. The value of this metric was somewhat different in the laminarizat...read more
Citations
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Numerical simulation of pulsating turbulent channel flow
Alberto Scotti,Ugo Piomelli +1 more
TL;DR: In this paper, the validity of the dynamic Smagorinsky model to study this kind of unsteady flow is established by a posteriori comparison with direct simulations and experimental data.
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Summary of Savonius wind turbine development and future applications for small-scale power generation
TL;DR: In this paper, the authors present a historical perspective on the Savonius turbines and discuss recent developments in analysis methods which intend to optimize the turbines for powering cellular communication towers in developing parts of the world.
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A new heat transfer correlation for transition and turbulent fluid flow in tubes
TL;DR: In this article, the authors developed a correlation for the Nusselt number Nu in terms of the friction factor ξ (Re), Reynolds number Re, and also Prandtl number Pr, which is valid for transitional and fully developed turbulent flow.
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Determining velocity and friction factor for turbulent flow in smooth tubes
TL;DR: In this article, a new simple and accurate correlation for the friction factor for Reynolds numbers between 3000 and 107 is proposed in the context of the Nusselt number for smooth tubes.
Journal ArticleDOI
Literature Survey of Numerical Heat Transfer (2000–2009): Part II
TL;DR: A comprehensive survey of the literature in the area of numerical heat transfer (NHT) published between 2000 and 2009 has been conducted by as mentioned in this paper, where the authors conducted a comprehensive survey.
References
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Journal ArticleDOI
Turbulent flow in pipes, with particular reference to the transition region between the smooth and rough pipe laws.
Journal ArticleDOI
A Correlation-Based Transition Model Using Local Variables—Part I: Model Formulation
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