The velocity profiles were calculated for stationary two-phase lammar flows m honzontal cylrndncal channels by means of solvmg the Navler-Stokes equations for different flow ratios The correspondmg velocity profiles were measured m water and toluene phases by means of constant temperature hot-film a
Flow patterns of two-phase helium in horizontal channels
β Scribed by A.I. Alexeyev; Yu.P. Filippov; I.S. Mamedov
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 915 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0011-2275
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β¦ Synopsis
This paper reports the investigation of the structure of two-phase helium flows used for cryostatically controlling superconducting magnets in installations such as HERA, NET, UNK and KEK. Flow pattern maps for horizontal round channels and rectangular slot channels are plotted on the basis of experimental data obtained for a wide range of flow parameter variations. Some typical features of the flows (e.g. the absence of a slug pattern) are pointed out and attempts are made to explain these features following a theoretical analysis. Methods for estimating stratification and full mix limits are proposed. The position of the limits on the maps obtained for helium is shown to be quite different from that of other two-phase mixtures.
π SIMILAR VOLUMES
The pressure drop and void fraction of two-phase helium in a horizontal flow loop driven by a single stroke bellows pump at mass flow rates ranging from 0.5 to 2.0 g s-' and under system pressures between 0.65 and 1.2 atm are reported. The slip ratio (the ratio of the velocity of the gaseous phase o
Information about the quality and flow patterns of helium two-phase flow has been obtained by using optical fibres and photo-sensitive devices. Light emitted from a LED is scattered by bubbles and turbulence in liquid helium. As bubbles and turbulence in liquid are related to the quality, x, the mea
pressure, to reach temperatures higher than 4.2 K. As was expected from Fig. la, the original data for the range from 2.25 to 5 K was found to be correct. However, data below the X-point (2.17 K) differed drastically in the two calibrations. The supplier could not explain this discrepancy, and the s
In the first part of this paper a theory for isothermal homogeneous two-phase, liquid-gas flow in horizontal pipes is established by introducing the concept of Mach number and by considering the medium to be a pseudo gas. The theory takes account of wall friction, compressibility and flow choking. A