0
Research Papers: Forced Convection

Influence of Thermal Buoyancy on Vortex Shedding Behind a Rotating Circular Cylinder in Cross Flow at Subcritical Reynolds Numbers

[+] Author and Article Information
Dipankar Chatterjee

Simulation & Modeling Laboratory,
CSIR—Central Mechanical Engineering
Research Institute,
Durgapur 713209, India
e-mail: d_chatterjee@cmeri.res.in

Chiranjit Sinha

Simulation & Modeling Laboratory,
CSIR—Central Mechanical Engineering
Research Institute,
Durgapur 713209, India

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received February 27, 2013; final manuscript received November 4, 2013; published online xx xx, xxxx. Assoc. Editor: James A. Liburdy.

J. Heat Transfer 136(5), 051704 (Feb 26, 2014) (10 pages) Paper No: HT-13-1103; doi: 10.1115/1.4026007 History: Received February 27, 2013; Revised November 04, 2013

The vortex shedding (VS) behind stationary bluff obstacles in cross-flow can be initiated by imposing thermal instability at subcritical Reynolds numbers (Re). We demonstrate here that additional thermal instability is required to be imparted in the form of heating for destabilizing the flow around a rotating bluff obstacle. A two-dimensional numerical simulation is performed in this regard to investigate the influences of cross buoyancy on the VS process behind a heated and rotating circular cylinder at subcritical Re. The flow is considered in an unbounded medium. The range of Re is chosen to be 5–45 with a dimensionless rotational speed (Ω) ranging between 0 and 4. At this subcritical range of Reynolds number the flow and thermal fields are found to be steady without the superimposed thermal buoyancy (i.e., for pure forced flow). However, as the buoyancy parameter (Richardson number, Ri) increases flow becomes unstable and subsequently, at some critical value of Ri, periodic VS is observed to characterize the flow and thermal fields. The rotation of the cylinder is found to have a stabilizing effect and as Ω increases more heating is observed to be required to destabilize the flow.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic of the physical problem

Grahic Jump Location
Fig. 2

Streamlines (left) and isotherms (right) around the cylinder at Re = 20 and without thermal buoyancy effect (Ri = 0) for different Ω

Grahic Jump Location
Fig. 3

Local Nu distribution for different Ω at Re = 20 and Ri = 0

Grahic Jump Location
Fig. 4

Stability diagram at different Ω, (a) Ω=0, (b) Ω=1, (c) Ω=2, and (d) Ω=4

Grahic Jump Location
Fig. 5

Contours of instantaneous vorticity magnitude at Re = 40 (a) Ri = 0.55 (left), and Ri = 0.60 (right) for Ω=0, (b) Ri = 0.65 (left) and Ri = 0.70 (right) for Ω=1, (c) Ri = 0.85 (left) and Ri = 0.90 (right) for Ω=2, and (d) Ri = 1.6 (left) and Ri = 1.65 (right) for Ω=4

Grahic Jump Location
Fig. 6

Variation of (a, c, and d) local surface vorticity and (b) baroclinic vorticity production along the surface of the cylinder at Re = 40 and for different Ω and Ri

Grahic Jump Location
Fig. 7

Variation of total positive and negative surface vorticity with Ω for Re = 40 and Ri = 0 and 1

Grahic Jump Location
Fig. 8

Variation of St with (a) Ri at Re = 40 and (b) Re at Ri = 1.5 and for different Ω

Grahic Jump Location
Fig. 9

Variation of time average (a, b) CD and (c, d) CL with Ri for different Re and Ω=0 and 4

Grahic Jump Location
Fig. 10

Variation of time and surface average Nu with Ri for different (a) Re at Ω=0 and (b) Ω at Re = 40

Tables

Errata

Discussions

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 eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In