Fluid Flow and Heat Transfer of Natural Convection around Heated Vertical Cylinders (Effect of Diameter)

摘要

Natural convective flows of water induced around vertical heated cylinder have been investigated experimentally. Special concerns were the effects of cylinder diameter on the turbulent transition and the local heat transfer characteristics. The flow visualizations and heat transfer measurements have been carried out. The result showed that the onset of turbulent transition shifts toward downstream and that the local heat transfer coefficients are increased with decreasing the cylinder diameter, in particular, when the diameter becomes smaller than 60mm.