The Influence of Structural Damping on Internal Pressure During a Transient Pipe Flow

A four equation model of axial wave propagation with Poisson coupling which includes viscous damping to account for structural energy dissipation is evaluated. Comparison of the predictions with experimental data indicates that the model can satisfactorily predict fluid pressure and structural velocity. The results show that structural damping reduces the pressure peaks during a transient event by eliminating the high frequency components. For the conditions studied, this reduction was 20 to 25 percent for a piping system with no axial constraints. A saddle-type support increases the equivalent viscous damping, and this increased damping can be modeled as either distributed damping or as an external damper.