The effects of support geometry on the turbulence response of loosely supported heat exchanger tubes

This paper reports the results of numerical simulations of a loosely supported heat exchanger tube excited by turbulence. The effects of support clearance and flow orientation are studied for various support geometries and lattice-bar support offset are investigated. The finite element method was utilized to model the vibrations and the impact dynamics. Three different friction models were examined to account for the tube/support friction forces and issues regarding the efficiency and accuracy of the different techniques are discussed. Tube response and tube/support interaction parameters, such as the impact force, the contact ratio, and most importantly, the integrated product of the contact force and the sliding distance (work rate), are presented. The study indicates that some flow orientations, support types, and support offsets provide favourable support conditions for higher tube sliding motion against the support and, therefore, potentially greater wear rates under service conditions.

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