Parametric Analysis of Turbulent Wall Jet in Still Air Over a Transitional Rough, With Asymptotes of Fully Rough and Fully Smooth Wall JetsSource: Journal of Fluids Engineering:;2013:;volume( 135 ):;issue: 011::page 111203DOI: 10.1115/1.4025005Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: The novel scalings for streamwise variations of the flow in a turbulent wall jet over a fully smooth, transitional, and fully rough surfaces have been analyzed. The universal scaling for arbitrary wall roughness is considered in terms of the roughness friction Reynolds number (that arises from the stream wise variations of roughness in the flow direction) and roughness Reynolds number at the nozzle jet exit. The transitional rough wall jet functional forms have been proposed, whose numerical constants power law index and prefactor are estimated from best fit to the data for several variables, like, maximum wall jet velocity, boundary layer thickness at maxima of wall jet velocity, the jet half width, the friction factor and momentum integral, which are supported by the experimental data. The data shows that the two asymptotes of fully rough and fully smooth surfaces are colinear with transitional rough surface, predicting same constants for any variable of flow for full smooth, fully rough and transitional rough surfaces. There is no universality of scalings in terms of traditional variables as different expressions are needed for each stage of the transitional roughness. The experimental data provides very good support to our universal relations.
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contributor author | Afzal, Noor | |
contributor author | Seena, Abu | |
date accessioned | 2017-05-09T00:59:18Z | |
date available | 2017-05-09T00:59:18Z | |
date issued | 2013 | |
identifier issn | 0098-2202 | |
identifier other | fe_135_11_111203.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl/handle/yetl/151960 | |
description abstract | The novel scalings for streamwise variations of the flow in a turbulent wall jet over a fully smooth, transitional, and fully rough surfaces have been analyzed. The universal scaling for arbitrary wall roughness is considered in terms of the roughness friction Reynolds number (that arises from the stream wise variations of roughness in the flow direction) and roughness Reynolds number at the nozzle jet exit. The transitional rough wall jet functional forms have been proposed, whose numerical constants power law index and prefactor are estimated from best fit to the data for several variables, like, maximum wall jet velocity, boundary layer thickness at maxima of wall jet velocity, the jet half width, the friction factor and momentum integral, which are supported by the experimental data. The data shows that the two asymptotes of fully rough and fully smooth surfaces are colinear with transitional rough surface, predicting same constants for any variable of flow for full smooth, fully rough and transitional rough surfaces. There is no universality of scalings in terms of traditional variables as different expressions are needed for each stage of the transitional roughness. The experimental data provides very good support to our universal relations. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Parametric Analysis of Turbulent Wall Jet in Still Air Over a Transitional Rough, With Asymptotes of Fully Rough and Fully Smooth Wall Jets | |
type | Journal Paper | |
journal volume | 135 | |
journal issue | 11 | |
journal title | Journal of Fluids Engineering | |
identifier doi | 10.1115/1.4025005 | |
journal fristpage | 111203 | |
journal lastpage | 111203 | |
identifier eissn | 1528-901X | |
tree | Journal of Fluids Engineering:;2013:;volume( 135 ):;issue: 011 | |
contenttype | Fulltext |