The effective Reynolds number of a heated cylinder
Résumé
The structure of the near wake behind a heated cylinder in air is investigated experimentally in the regime corresponding to the transition from a 2-D steady to a 2-D periodic wake. In this non-isothermal case an effective Reynolds number, Re-eff,,, is used to characterize the flow regime. The corresponding effective temperature is found to be T-infinity+0.24(T-w-T-infinity,) and is lower than the usual him temperature T-film,, = T-infinity + 0.5(T-w-T-infinity,). The structure of the velocity fields in the wake downstream the heated cylinder is found to be correctly characterized by this effective Reynolds number. Over this flow regime, Nusselt numbers are found to be dependent on a Reynolds number intermediate between Re-eff and Re-film. (C) 1998 Elsevier Science Ltd. All rights reserved.