The behaviour of a tube bundle near the stability limit

Abstract

Tube heat exchangers are inseparable components of a great number of energetic machinery, where one fluid flows through tubes and the other fluid flows around the tubes. Heat transfer occurs between these two fluids. Apart from the problem of heat transfer, the problem of fluid-structure interaction is very important too. Mainly the fluid flowing around the tubes may be very dangerous, because it causes vibrations of these tubes. Intensity of vibration depends on the velocity of the flow. Under the certain, so-called critical velocity, vibration amplitudes can have random pattern. The objective of this article is to determine the probability of up crossing of some fixed level. It is necessary to avoid such regimes of operations, in which the damage of a heat exchanger as a consequence of flow-induced vibration could be caused.