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ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

WALL TEMPERATURE FLUCTUATION OF THE EVAPORATING TUBE AT THE DRYOUT REGION

Get access (open in a dialog) DOI: 10.1615/IHTC7.1140
pages 315-320

Résumé

An experimental study of the wall temperature fluctuation of the evaporating tube at the dryout region is conducted on a uniformly heated vertical tube in which water flows upward; the experimental condition is as follows: the pressure is 2.95 MPa, the mass flux 500 kg/m2s, and the heat flux up to 0.7 MW/m2. The development of the wall temperature along the tube and the influence of the heat flux on its behavior are analyzed by using the FFT method. The pressure drop across the evaporating tube is also analyzed. It is found that the wall temperature fluctuation is rather mild and shows considerable randomness unless the incoming flow to the eavaporating tube is unstable, and that, when the flow is destabilized, the spectrum of the wall temperature has an eminent peak at some frequency not higher than 0.3 Hz. The spectra are classified into six modes and the pattern map is constructed. It is suggested from examination of the pressure drop spectrum data that the disturbance wave might have any relation with the fluctuation phenomenon.