Dry patch stability of shear driven liquid film
The breakdown of the liquid film at the wall in annular gas-liquid flow may lead to the formation of a stable dry patch. For the case of heat transfer surfaces this causes a hot spot, The dry patch is a partial area on the solid surface that is non-wetted due to a local disturbance of the flow and is sustained by surface tension. Dry patch stability is dependent on a balance of body and surface forces. In the present study the interfacial shear force drives the film and the gravity force is negligible. A new computational fluid dynamics (CFD) solution of the flow field in the film around the dry patch has been obtained. The CFD results confirm Murgatroyd's shear force model (1965), although the details are more complex. Furthermore, there is agreement between the CFD solution and the experimental value of the characteristic length scale, L, for the shear force. In addition new experimental data have been taken for adiabatic upward annular air-water and air-ethylene glycol flows at room temperature in a 9.5 mm diameter tube. They provide validation of Murgatroyd's model over a wider range of the film's Reynolds number than previous data.
- Research Organization:
- Bettis Atomic Power Lab., West Mifflin, PA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC11-98PN38206
- OSTI ID:
- 770675
- Report Number(s):
- B-T-3228; TRN: AH200131%%99
- Resource Relation:
- Other Information: PBD: 1 May 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
Annular flow entrainment rate experiment in a vertical pipe
Computational Fluid Dynamics Best Practice Guidelines in the Analysis of Storage Dry Cask