Vibration of a tube bundle in two-phase Freon cross-flow
- AECL Research, Chalk River, Ontario (Canada). Chalk River Labs.
- Univ. of Toronto, Ontario (Canada). Dept. of Mechanical Engineering
Two-phase cross-flow exists in many shell-and-tube heat exchangers. The U-bend region of nuclear steam generators is a prime example. Testing in two-phase flow simulated by air-water provides useful results inexpensively. However, two-phase flow parameters, in particular surface tension and density ratio, are considerably different in air-water than in steam-water. A reasonable compromise is testing in liquid-vapor Freon, which is much closer to steam-water while much simpler experimentally. This paper presents the first results of a series of tests on the vibration behavior of tube bundles subjected to two-phase Freon cross-flow. A rotated triangular tube bundle of tube-to-diameter ratio of 1.5 was tested over a broad range of void fractions and mass fluxes. Fluidelastic instability, random turbulence excitation, and damping were investigated. Well-defined fluidelastic instabilities were observed in continuous two-phase flow regimes. However, intermittent two-phase flow regimes had a dramatic effect on fluidelastic instability. Generally, random turbulence excitation forces are much lower in Freon than in air-water. Damping is very dependent on void fraction, as expected.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 131622
- Journal Information:
- Journal of Pressure Vessel Technology, Vol. 117, Issue 4; Other Information: DN: Paper presented at the Pressure Vessels and Piping Conference, Minneapolis, MN (US), June 19--23, 1994; PBD: Nov 1995
- Country of Publication:
- United States
- Language:
- English
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