This paper reports the results of the numerical simulation of a loosely-supported heat exchanger tube excited by turbulence. The effect of support clearance, support geometry, and flow orientation are investigated. The finite element method is utilized to model the vibrations and impact dynamics. Three different friction models are examined to account for the tube/support friction forces. 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 and support geometries provide favourable support conditions for higher tube sliding motion against its support and therefore, potentially greater wear rates under service conditions.