Mixed convection around a heated cylinder

Both experimental and numerical techniques are used to study the vortex formation process behind a heated circular cylinder. The hydrogen bubble visualization experiments are executed to investigate the evolution of the shedded structures while preliminary Particle Tracking Velocimetry (PTV) data and 2-D Spectral Element Method (SEM) calculations are used to investigate the vortex formation process under influence of the induced heat. The typical value for the Reynolds number Re-D is equal to 73 and the Richardson number Ri(D) is varied between 0 and 1.5. The purely forced convection vortex shedding mechanism for low Reynolds numbers as described by Green and Gerrard [3] is used as starting point for this investigation. The observed effects of the induced heat are an increasing difference in strength between the upper and lower vortex rows and for higher Ri(D) numbers the early break down of the Von Karman vortex street.