The influence of upstream turbulence on the stability of tube bundles subjected to cross-flow

Book · Sun Dec 01 04:00:00 EST 1996

OSTI ID:403373

Romberg, O; Popp, K ^[1]

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1. Univ. of Hannover (Germany). Inst. of Mechanics

Tube failures in heat exchangers are often caused by inadmissible vibrations. Especially the fluidelastic instability is a dangerous excitation mechanism. The investigations refer to the influence of isotropic upstream turbulence on the stability behavior of parallel and rotated triangular tube arrays of different pitch-to-diameter ratios. The excitation is due to air cross-flow in a wind tunnel. The experimental apparatus allows to measure the stability boundaries (Connors diagram) of fully flexible bundles as well as single flexibly mounted tubes with variable equilibrium position in otherwise fixed arrays. By using a turbulence grid with variable geometric properties it is possible to produce isotropic turbulence with variable turbulence intensity Tu and scale length L{sub x} at the inlet of the bundle. These values were determined using hot wire anemometers. The investigations show in most of the cases a stabilization of the tubes with increasing turbulence.

• OSTI ID: 403373
• Report Number(s): CONF-960706--; ISBN 0-7918-1775-X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CROSSFLOW SYSTEMS
EXPERIMENTAL DATA
FLUID-STRUCTURE INTERACTIONS
HEAT EXCHANGERS
MECHANICAL VIBRATIONS
TURBULENT FLOW