A special kind of analysis: CFD modeling for design and assessment of bridge passive control devices

During its life-cycle a structural system is generally subject to both static and dynamic loads: for the second type of actions inertial effects become more important resulting in dynamic amplification and cyclic response. The effects of such loads can be controlled for example by adopting passive energy dissipation that can be effective against seismic and wind induced motion requiring no kind of external supply. In this work a viscous fluid damper with annular orifice is deeply investigated with the aim to set up a reliable numerical model supporting the design phase. After giving a brief description of the basic fluiddynamic and rheological equations, analytical solution is provided for both Newtonian and Non-Newtonian incompressible viscous fluid as a reference. Subsequently a preliminary finite element model reproducing the annular conduit and the near-field portion of the lateral chamber is set up by means of two commercial codes: comparison of result allows to evaluate accuracy of the numerical solutions and the influence of the relevant model parameters.