Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

COMBINED FREE AND FORCED CONVECTION IN A VERTICAL AND INCLINED CYLINDRICAL ANNULUS

Get access (open in a dialog) DOI: 10.1615/IHTC8.2890
pages 1401-1406

Abstrakt

An experimental investigation is reported of superposed free and forced convection in an internally heated concentric annulus in vertical, inclined and horizontal position. Both upflow and downflow are considered in the concentric annulus having an equivalent diameter of 16 mm and a heated core of 1 m length. Reynolds number ranges from 350 to 20 000, Grashof number from 105 to 108, and Prandtl number from 2.3 to 75. The results show an increase of Nusselt number in the regime of laminar flow and combined convection. As the annulus inclination deviates from vertical, the Nusselt number changes. Characteristic values of Rayleigh and Reynolds numbers describe this effect. In the case of turbulent flow Nusselt number decreases with ratio of Grashof-to-Reynolds number and with angle of inclination. The measured heat transfer data are also presented in form of correlation equations.