On the Suitability of the Low Mach Number Assumption in the Modeling of the Damage Induced by Pressure Transients in Piping Systems

One-dimensional models for predicting the damage induced by pre.ʹi.ʹiure transienti in piping systems conveying liquids have been proposed and analysed recently. However, such works have been concerned mainly with the adequacy of the constitutive equations adopted for different pipe materials and with the numerical techniques used for approximating the solution of the refmltmg mathematical problems. In the present paper the suitahility of the simpilfying low Mach number assumption adopted in the modeling is investigated. The analysis is carried out based on the eigenvalue problem associated to the governing equations, without appealing to any specific mechanical behavior of the pipe material. Numerical results obtained for the most used pipe materials show that this simplifying assumption is adequate for metallic tubes, but may fail when plastic tubes are considered.