Experimental Verification and Revision of the Venting Rate Model of the Hazard Assessment Computer System and the Vulnerability Model

摘要

A model developed previously as part of the Hazard Assessment Computer System to predict the discharge rate of a chemical cargo from a punctured ship tank has been revised and verified. The computerized model can now treat: (1) a puncture above, below, or intersecting the waterline; (2) vacuum relief valve actuations; (3) simultaneous liquid and gas discharge; (4) volatile or nonvolatile cargo; and (5) air or water ingestion into the tank, to permit additional cargo to be discharged. The model is based on an analysis of such thermodynamic and fluid flow phenomena as two-phase and choked flow and realistic evaporation rates within the tank. The Chemical Properties File was examined for its applicability to the revised model, and some desirable improvements were indicated. Experimental verification of the model consisted of a series of extensively instrumented tests of small tanks to investigate: (1) discharge coefficients of irregularly shaped punctures; (2) air and water ingestion; and (3) discharge of volatile and boiling liquids. The good comparison of the model to the tests adequately verified the model. (Author)