Daniel A. Crowl

Calculating the energy of explosion using thermodynamic availability

Abstract Thermodynamic availability represents the maximum mechanical energy extractable from a material as it reversibly moves into equilibrium with the environment. Since blast overpressure is a form of mechanical energy, thermodynamic availability provides a new and completely general technique for determining the energy of explosion. This paper presents the fundamental basis and shows how thermodynamic availability is used to determine the energy of explosion. It is shown that the method is applicable for any process conditions, including systems at elevated temperatures and pressures and systems composed of many materials, and for reactive explosion and explosions of inert compressed gases. The calculations are quite simple, even for the most complex cases. A table of thermodynamic data and a number of worked examples are provided.

Liquid discharge from process and storage vessels

Abstract A generalized model to represent the orifice discharge of liquid from any point on the surface of a storage or process vessel is presented. The model is useful for determining the vessel leakage characteristics for specified geometries or using numerical volume versus height data acquired from the tank. Specific results are presented for vented tank geometries represented by tanks of constant cross-section (vertical cylinders and rectangular tanks), horizontal cylinders and spheres. Both algebraic and numeric results are presented. An interesting result is that the maximum leakage time for the sphere occurs when the leak is 25% of the diameter above the bottom of the tank. For the horizontal cylinder, the maximum leakage time occurs for leak 17% of the diameter above the bottom.

A Real-Time Fortran Executive

This executive provides its users with sophisticated real-time functions without requiring them to do a lot of complicated assembly language interfacing.