Title

Transition phenomena and velocity distribution in constant-deceleration pipe flow

Authors

Authors

H. Saka; Y. Ueda; K. Nishihara; O. J. Ilegbusi;M. Iguchi

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Exp. Therm. Fluid Sci.

Keywords

Unsteady flow; Pipe flow; Constant-deceleration flow; Turbulence; transition; TURBULENCE; IDENTIFICATION; LAMINAR; REST; Thermodynamics; Engineering, Mechanical; Physics, Fluids & Plasmas

Abstract

The critical Reynolds number for transition to turbulence in a constant-acceleration pipe flow is well known to be significantly higher than the value for steady pipe flow. This is a consequence of the significant suppression of amplification of disturbances entering the pipe by the acceleration in spite of the increase of inertial force due to increase in instantaneous Reynolds number. In contrast, relatively little is known of the transition phenomena in a constant-deceleration pipe flow. Such a flow system is investigated by an experimental method in which the cross-sectional mean velocity is initially kept constant and subsequently decreased linearly to zero. The characteristics of the transition phenomena will be determined by two factors deceleration and viscosity. Deceleration will amplify the disturbances, while a decrease in the instantaneous Reynolds number is expected to suppress the amplification of the disturbances due to viscosity. The study uses hot-wire experiments to clarify which of the two effects predominates in constant-deceleration pipe flow. (C) 2014 Elsevier Inc. All rights reserved.

Journal Title

Experimental Thermal and Fluid Science

Volume

62

Publication Date

1-1-2015

Document Type

Article

Language

English

First Page

175

Last Page

182

WOS Identifier

WOS:000350074100018

ISSN

0894-1777

Share

COinS