On the relationship of effective Reynolds number and Strouhal number for the laminar vortex shedding of a heated circular cylinder

Abstract

The laminar vortex shedding of airflow behind a circular cylinder with different heating temperatures was experimentally investigated with emphasis on the relationship of wake frequency and the Reynolds number. A new method to generate the two-dimensional parallel vortex shedding for the heated cylinder was developed and tested. An “effective Reynolds number” that employs a kinematic viscosity computed from an “effective temperature” is used to account for the temperature effects on the vortex shedding frequency. The present result shows that the frequency data could be successfully collapsed with the effective temperature computed by Teff=T∞+0.28(TW−T∞) for a wide range of cylinder temperatures, T∞ and TW being the free-stream temperature and cylinder surface temperature, respectively. Moreover, the relationship between Strouhal number and effective Reynolds number was found to be “universal.” The physical interpretation of Teff and the applicable region of the St–Reeff curve are discussed.

Experimental and numerical investigation of the vortex formation process behind a heated cylinder

“…When the cylinder is exposed to a horizontal cross flow, Lecordier et al 9 and Wang et al 10 observed that for a Reynolds number just above the critical value of Re c ϭ49 the vortex shedding could be suppressed by a small amount of heat input to the cylinder in air. Heating the wake flow has an opposite effect in air and water, due to the difference in the thermal dependence of the kinematic viscosity.…”

Lift-up process in a heated-cylinder wake flow

“…For a horizontal mounted cylinder, the vortex shedding can be suppressed by heating of the cylinder at Reynolds values just above the critical value: Re c =49 ͑Lecordier et al, 5 Wang et al 6 ͒. In Lecordier et al, 7 the sudden disappearance of the vortex shedding phenomenon is analyzed and it is concluded that the influence of the temperature on the viscosity is the primary source.…”

Influence of strouhal number on the temperature fields in the locked space with the working source of the radiant heating

“…In this case are used or standard balance models [2] or systems of nonstationary differential equations [1] into the partial derivatives, which consider the influence of different parameters, entering the dimensionless criteria, such, for example, as numbers of Prandtl, Reynolds and others. The number of studies is dedicated to the study of the influence of the criterion of eddy formation (Strouhal number) on the structure of the flow of gas or liquid after passage by them the obstacle [5][6][7][8][9]. Strouhal number is correlated with this phenomenon as the instability of the flow of working medium.…”