SIMULATION OF 2-DIMENSIONAL SQUEEZE FILM AND SOLID CONTACT FORCES ACTING ON A HEAT-EXCHANGER TUBE

Based on a short-length cylindrical squeeze film model, a simplified t wo-dimensional dynamic model for the interaction of a heat exchanger t ube and its support, with transitions to and from solid contact, has b een developed. The model includes estimations of the tube/support defl ection, the effects of the surface roughnesses and tube/support inclin ation. A test computer code based on the model has been developed whic h calculates the normal and tangential squeeze film forces and solid c ontact forces acting on the tube with large amplitude arbitrary motion s. As well, the code has been extended to simulate a mass with six deg rees of freedom. The model and algorithm have been verified by numeric al analysis and comparisons. The VIBIC finite element computer code wh ich simulates the dynamic response of a heat exchanger tube as it impa cts and rubs against its supports has been improved and updated by imp lementing the test code into it. The simulation results appear reasona ble. (C) 1997 Academic Press Limited.