The influence of temperature gradient on the Strouhal-Reynolds number relationship for water and air

T. Vit, M. Ren, Z. Travnicek, F. Marsik, C.C.M. Rindt

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)
5 Downloads (Pure)

Abstract

This paper focuses on the wake flow behind a heated circular cylinder in the laminar vortex shedding regime. The phenomenon of vortex shedding from a bluff body is an interesting scientific and engineering problem. Acquisition of reliable experimental data is considered an indispensable step toward a deeper physical understanding of the topic. An experimental study of the wake flow behind a heated cylinder in the forced convection regime is performed using water as the working fluid. Firstly, qualitative visualization experiments were performed and the parallel vortex shedding mode was adjusted. Next, hot-wire anemometry was used for St–Re data acquisition. Data analysis confirmed the so-called thermal effect in water: cylinder heating increases the vortex shedding frequency and destabilizes the wake flow. The effective temperature concept was used and the St–Re data were successfully transformed to the St–Reeff curve. Furthermore, a comparison with air as the working fluid was discussed (cylinder heating decreases the vortex shedding frequency in air, thus stabilizing the wake flow). The formula to determine the effective temperature in water was experimentally derived from the present data, while the data and formula for air is already known. The relationship between the Strouhal number and the effective Reynolds number for water and air is represented by the same, universal formula: , where Reeff is calculated at the effective temperature. Finally, the measurement results were compared to the thermodynamic St–Re equation derived by Maršík et al. [F. Maršík, Z. Trávnícek, R.H. Yen., A.-B. Wang, Fluid dynamics concept for the critical Reynolds number of a heated/cooled cylinder in laminar crossflow, in preparation]. A satisfactory agreement between the derived equation and experimental data for both fluids (water and air) was achieved
Original languageEnglish
Pages (from-to)751-760
JournalExperimental Thermal and Fluid Science
Volume31
Issue number7
DOIs
Publication statusPublished - 2007

Fingerprint

Vortex shedding
Thermal gradients
Reynolds number
Water
Air
Fluids
Heating
Strouhal number
Forced convection
Circular cylinders
Fluid dynamics
Thermal effects
Temperature
Data acquisition
Visualization
Wire
Thermodynamics
Experiments

Cite this

@article{558ef643959c4bde9867f70588cddd1d,
title = "The influence of temperature gradient on the Strouhal-Reynolds number relationship for water and air",
abstract = "This paper focuses on the wake flow behind a heated circular cylinder in the laminar vortex shedding regime. The phenomenon of vortex shedding from a bluff body is an interesting scientific and engineering problem. Acquisition of reliable experimental data is considered an indispensable step toward a deeper physical understanding of the topic. An experimental study of the wake flow behind a heated cylinder in the forced convection regime is performed using water as the working fluid. Firstly, qualitative visualization experiments were performed and the parallel vortex shedding mode was adjusted. Next, hot-wire anemometry was used for St–Re data acquisition. Data analysis confirmed the so-called thermal effect in water: cylinder heating increases the vortex shedding frequency and destabilizes the wake flow. The effective temperature concept was used and the St–Re data were successfully transformed to the St–Reeff curve. Furthermore, a comparison with air as the working fluid was discussed (cylinder heating decreases the vortex shedding frequency in air, thus stabilizing the wake flow). The formula to determine the effective temperature in water was experimentally derived from the present data, while the data and formula for air is already known. The relationship between the Strouhal number and the effective Reynolds number for water and air is represented by the same, universal formula: , where Reeff is calculated at the effective temperature. Finally, the measurement results were compared to the thermodynamic St–Re equation derived by Marš{\'i}k et al. [F. Marš{\'i}k, Z. Tr{\'a}vn{\'i}cek, R.H. Yen., A.-B. Wang, Fluid dynamics concept for the critical Reynolds number of a heated/cooled cylinder in laminar crossflow, in preparation]. A satisfactory agreement between the derived equation and experimental data for both fluids (water and air) was achieved",
author = "T. Vit and M. Ren and Z. Travnicek and F. Marsik and C.C.M. Rindt",
year = "2007",
doi = "10.1016/j.expthermflusci.2006.08.002",
language = "English",
volume = "31",
pages = "751--760",
journal = "Experimental Thermal and Fluid Science",
issn = "0894-1777",
publisher = "Elsevier",
number = "7",

}

The influence of temperature gradient on the Strouhal-Reynolds number relationship for water and air. / Vit, T.; Ren, M.; Travnicek, Z.; Marsik, F.; Rindt, C.C.M.

In: Experimental Thermal and Fluid Science, Vol. 31, No. 7, 2007, p. 751-760.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - The influence of temperature gradient on the Strouhal-Reynolds number relationship for water and air

AU - Vit, T.

AU - Ren, M.

AU - Travnicek, Z.

AU - Marsik, F.

AU - Rindt, C.C.M.

PY - 2007

Y1 - 2007

N2 - This paper focuses on the wake flow behind a heated circular cylinder in the laminar vortex shedding regime. The phenomenon of vortex shedding from a bluff body is an interesting scientific and engineering problem. Acquisition of reliable experimental data is considered an indispensable step toward a deeper physical understanding of the topic. An experimental study of the wake flow behind a heated cylinder in the forced convection regime is performed using water as the working fluid. Firstly, qualitative visualization experiments were performed and the parallel vortex shedding mode was adjusted. Next, hot-wire anemometry was used for St–Re data acquisition. Data analysis confirmed the so-called thermal effect in water: cylinder heating increases the vortex shedding frequency and destabilizes the wake flow. The effective temperature concept was used and the St–Re data were successfully transformed to the St–Reeff curve. Furthermore, a comparison with air as the working fluid was discussed (cylinder heating decreases the vortex shedding frequency in air, thus stabilizing the wake flow). The formula to determine the effective temperature in water was experimentally derived from the present data, while the data and formula for air is already known. The relationship between the Strouhal number and the effective Reynolds number for water and air is represented by the same, universal formula: , where Reeff is calculated at the effective temperature. Finally, the measurement results were compared to the thermodynamic St–Re equation derived by Maršík et al. [F. Maršík, Z. Trávnícek, R.H. Yen., A.-B. Wang, Fluid dynamics concept for the critical Reynolds number of a heated/cooled cylinder in laminar crossflow, in preparation]. A satisfactory agreement between the derived equation and experimental data for both fluids (water and air) was achieved

AB - This paper focuses on the wake flow behind a heated circular cylinder in the laminar vortex shedding regime. The phenomenon of vortex shedding from a bluff body is an interesting scientific and engineering problem. Acquisition of reliable experimental data is considered an indispensable step toward a deeper physical understanding of the topic. An experimental study of the wake flow behind a heated cylinder in the forced convection regime is performed using water as the working fluid. Firstly, qualitative visualization experiments were performed and the parallel vortex shedding mode was adjusted. Next, hot-wire anemometry was used for St–Re data acquisition. Data analysis confirmed the so-called thermal effect in water: cylinder heating increases the vortex shedding frequency and destabilizes the wake flow. The effective temperature concept was used and the St–Re data were successfully transformed to the St–Reeff curve. Furthermore, a comparison with air as the working fluid was discussed (cylinder heating decreases the vortex shedding frequency in air, thus stabilizing the wake flow). The formula to determine the effective temperature in water was experimentally derived from the present data, while the data and formula for air is already known. The relationship between the Strouhal number and the effective Reynolds number for water and air is represented by the same, universal formula: , where Reeff is calculated at the effective temperature. Finally, the measurement results were compared to the thermodynamic St–Re equation derived by Maršík et al. [F. Maršík, Z. Trávnícek, R.H. Yen., A.-B. Wang, Fluid dynamics concept for the critical Reynolds number of a heated/cooled cylinder in laminar crossflow, in preparation]. A satisfactory agreement between the derived equation and experimental data for both fluids (water and air) was achieved

U2 - 10.1016/j.expthermflusci.2006.08.002

DO - 10.1016/j.expthermflusci.2006.08.002

M3 - Article

VL - 31

SP - 751

EP - 760

JO - Experimental Thermal and Fluid Science

JF - Experimental Thermal and Fluid Science

SN - 0894-1777

IS - 7

ER -