Flow characteristics on a heated rotating disc under natural convection dominant conditions

Characteristics of circumferential vortices, which emerge on a heated rotating disc under natural convection dominant conditions, have been studied experimentally. The techniques of laser induced fluorescence (LIF) and particle image velocimetry (PIV) have been utilized as a non-invasive method to obtain two-dimensional temperature and velocity distributions, respectively. The results show that the frequency of appearance of the vortex increases with increasing buoyancy effect. The ensemble averages of the temperature and vertical velocity as well as those of RMS values of temperature and vertical velocity fluctuations are large in the vortex. Most of heat is transferred vertically by fluctuations in the vortex.