Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

HORIZONTAL GAS-LIQUID FLOW : VISUALISATION AND ENTRADNMENT MEASUREMENTS

Get access (open in a dialog) DOI: 10.1615/IHTC10.5590
pages 247-252

Abstrakt

The structure of gas-liquid flow in a horizontal perspex tube has been examined. Data were obtained for the horizontal flow of an air/water mixture in a0.032 m I.D. tube held at pressures of 1.1-1.4 baia and ambient temperature. The two-phase flow was allowed to develop along a 5.3 m section at which point (i) flow visualization was studied using a high speed cine film and(ii) the liquid film flow rate was measured using the film removal technique. Tests WCTC carried out over a range of conditions which support both stratified and annular flows.
For low liquid and gas mass flux conditions the liquid film was confined to a small area at the bottom of the tube. As the gas velocity was increased the liquid film was drawn up the sides of the tube.
At slightly higher liquid flows the surface of the film roughened and disturbance waves appeared. The visualisation studies clearly showed that droplets were torn from these waves and entrained into the gas flow. A proportion of these droplets were seen to deposit on the top inside surface of the tube. These droplets coalesced to form rivulets which at higher liquid mass flux conditions combined to form a continuous film on the inside of the tube.
To model heat transfer in two-phase flows it is important to know the wetted perimeter and the liquid distribution between the film and the entrained droplets. This paper presents new data on (i) the wetted perimeter and (ii) the quantity of entrained liquid. The data are compared against a variety of correlations.