Abstract
When asymmetrical conditions exist around a heated element cooled by flow in a channel, the temperature varies round its circumference. This results in a tendency for the hottest side of the element to bow away from its nominal axis. Usually a movement in this direction reduces the heat transfer coefficient and increases the local coolant temperature on the hot side, inducing greater temperature differences around the element in addition to further movement. Under some conditions this can lead to complete instability. This problem has previously been examined for the case of an element simply supported at each end, with reference to fuel elements for nuclear reactors. A more general approach has now been made. The behaviour of two- and three-span continuous elements has been examined using a digital computer programme. The previous solution has been extended to cover any channel shape and any number of spans. Experiments with two- and three-span elements have confirmed the predictions.
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