Studies of vertical annular gas-liquid flows
Three types of vertical flowing films were studied. These are the free falling film, the falling film in the presence of countercurrent gas flow, and the upward moving film due to concurrent flow of gas. An experimental program was performed based on a new electrochemical method for the dynamic measurement of the magnitude and the direction of the wall shear stress, and on a conductance wire probe for the simultaneous measurement of the film thickness. Pressure drop was measured over a short distance with a differential pressure transducer. The data obtained for the free falling film reveal a strong length effect on the wavy-film structure. The measured variation of the wall shear stress along a wave suggests that a mixing vortex exists in the wave front followed by the development of a hydrodynamic boundary layer in the wave back. Analysis of the data taken with counter current flow of gas shows that even at the flooding condition, the film flow is controlled by downward wave motion. Measured wall shear stress was found to be upward directed and decreasing in magnitude with increasing gas rate. Analyses of the upward film flow data in a variety of ways suggest that, at low gas rates, the motion of the interface is controlled by a process of switching between possible steady states of the system. This condition is usually designated as churn flow but bridging of the liquid across the pipe as associated with churning does not occur.
- Research Organization:
- Houston Univ., TX (USA)
- OSTI ID:
- 5597211
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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