0
Research Papers: Fundamental Issues and Canonical Flows

# Destabilization of Laminar Wall Jet Flow and Relaminarization of the Turbulent Confined Jet Flow in Axially Rotating Circular Pipe

[+] Author and Article Information
Snehamoy Majumder1

Department of Mechanical Engineering, Jadavpur University, Kolkata 700 032, India

Dipankar Sanyal

Department of Mechanical Engineering, Jadavpur University, Kolkata 700 032, Indiasrg̱maj@yahoo.com

1

Corresponding author.

J. Fluids Eng 130(1), 011203 (Jan 16, 2008) (8 pages) doi:10.1115/1.2813068 History: Received September 07, 2006; Revised June 27, 2007; Published January 16, 2008

## Abstract

Destabilization and relaminarization phenomena have been investigated in an axially rotating circular duct. Standard $k-ε$ model with modification for streamline curvature has been used in the numerical study. The laminar and turbulent velocity distributions at inlet have been observed to become turbulent and laminar, respectively, toward the exit of the pipe. A local velocity profile with parabolic or nearly uniform variation has been considered as the characteristic of laminarlike or turbulent flow, respectively, and changeover of flow from former to the later variation or vice versa has been taken to characterize destabilization and relaminarization, respectively. The predicted azimuthal velocity component was found to be reasonably accurate near the wall and not so encouraging in the core region of the swirling flow. The recirculation bubble generated by a central jet flow at the wall has been observed to reduce in size due to rotation of the pipe confirming the relaminarization phenomenon, whereas with laminar wall jet waspredicted recirculation bubble growing with rotation rate manifesting the destabilization effects.

<>

## Figures

Figure 1

Flow geometry with rotation and inlet conditions

Figure 2

Streamline coordinate system

Figure 5

Destabilization of the laminar wall jet flow due to rotation

Figure 6

Destabilization of the laminar wall jet flow due to rotation

Figure 7

Nomenclature of the wall recirculation of a jet flow

Figure 8

Increase of recirculation length of the laminar wall jet due to rotation

Figure 9

Increase of recirculation breadth of the laminar wall jet due to rotation

Figure 10

Relaminarization of the pipe flow (compared with Ref. 18, Re=20,000)

Figure 11

Effect of rotation rate on recirculation (a) width and (b) length

Figure 3

Validation of the present method with the stationary pipe flow

Figure 4

Validation of the present results with swirling pipe flow (Re=48,000)

Figure 12

Decrement of recirculation size with increase in rotation rate at Re=40,223

Figure 13

Radial distribution of turbulent shear stress (u′v′¯∕Umean2)

Figure 14

Radial distribution of turbulent shear stress (u′w′¯∕Umean2)

Figure 15

Radial distribution of structure parameter (u′v′¯∕q2)

Figure 16

Variation of friction factor with rotational rate

Figure 17

Variation of total turbulent energy flux with rotational rate

## Errata

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections