(104bg) A Review of Liquid Discharge Models Under Non-Steady or Transient Conditions for More Realistic Predictions of the Magnitude and Impact of Consequences Related with Loss of Containment Events

A key element to determine the magnitude of impacts related with a loss of containment event is the calculation of the volume or inventory of fluid released to the environment. To estimate such volume, discharge models for liquids are normally applied under the assumption that the discharge rate is constant during the release.

The analysis of industrial accidents related with liquid releases shows in many cases that the discharge rate occurs as a non-steady or transient discharge instead of a continuous discharge.  In these cases, the assumption that the discharge rate is constant, can lead to overestimations of impacts or damages related with the development of fires and/or explosions.

Models of liquid discharge are reviewed here when non-steady or transient discharge conditions occur on an hypothetical scenario of accidental release. A set of basic guidelines are obtained to help risk analyst in evaluating when it is convenient to apply the assumption of constant discharge rate throughout the release and when it is preferable to use non-steady or transient discharge models. The application of non-steady or transient discharge models in liquids can result in a more realistic prediction of the total volume or inventory of fluid released to the environment.