Explosion/blast design methods

In this section, three examples of blast calculations of BLEVEs and pressure vessel bursts will be given. The first example is designed to illustrate the use of all three methods described in Section 6.3.2. The second is a continuation of sample problem 9.1.5, the BLEVE of a tank truck. A variation in the calculation method is presented instead of determination of the blast parameters at a given distance from the explosion, the distance is calculated at which a given overpressure is reached. The third example is a case study of a BLEVE in San Juan Ixhuatepec (Mexico City). 

Various methods are available to limit the damage from the effects of an explosion. The best options are to provide some pre-installed or engineered features into the design of the facility or equipment that allow for the dissipation or diversion of the effects of a blast to nonconsequential areas. Wherever these mechanisms are used the overpressure levels utilized should be consistent with the risk analysis estimates of the WCCE incident. 

Cook (Ref 17, p 36) designates the available energy as A, and states that this property, as well as the heat of explosion Q, and the ratio A/Q are the important quantities determining the total blast or "avaiable work potential or "available energy . The theory is presented in Chapter 11 of Ref 17, pp 265ff and is considered more reliable than experimental procedures, at least for CHNO expls. The experimental procedures referred to by Cook for determination of (A) include Trauzl Block Test and Ballistic Mortar Test. New methods have been proposed, such as determination of peak pressure or/and total energy ... 

Here, R4 is the initial radius of the hemispherical explosive charge and the constants Q and C2 reflect the volumes encompassed by a hemispherical blast wave instead of the spherical blasts for which the solution was initially designed. Although the original authors of this formula choose to evaluate Eq. 12 in terms of an elliptic integral [205], a simple computational solution utilizing a fourth-order Runge-Kutta method was employed here. 

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