Heat Transfer Measurements on a Rotating Disk

[摘要] Heat transfer to a rotating disk is measured for a wide range of Reynolds number values inthe laminar, transitional and turbulent flow regimes. Measurements are performed by makinguse of the heated-thin-foil technique and by gauging temperature maps with an infraredscanning radiometer. The use of the IR radiometer is advantageous on account of its relativelygood spatial resolution and thermal sensitivity and because it allows one to performmeasurements down to very low local Reynolds numbers. Data is obtained on three disks,having an external diameter varying from 150mm to 450mm; the smallest disk is used onlyto measure the adiabatic wall temperature and can rotate up to 21,O00rpm. Heat transferresults are presented in terms of Nusselt and Reynolds numbers based on the local radius andshow a substantial agreement with previous experimental and theoretical analyses. Transitionto turbulent flow is found at aboutRe=250,000. A discussion about the role played by the adiabatic wall temperature is also included.

[学科分类] 力学，机械学