The TNT equivalent model is often used as a simple method of estimating the mass of TNT per mass unit fuel gas whose detonation results in the same blast wave at the same distance. One kg of TNT translates into an energy of 4520 kJ. The equivalent for hydrogen is 2.22 kg TNT per Nm gas. The weakness of this model is to ignore the pressure-time characteristic differences between a gas cloud and a detonative TNT explosion. In the short range, the model overestimates the pressure. Furthermore the model does not take into account the influence of turbulence and confinement [113]. [Pg.219]

The TNT equivalent model requires the specification of the explosion efficiency. The TNO multi-energy method requires the specification of the degree of confinement and the specification of a relative blast strength. [Pg.149]

The largest potential error with the TNT equivalency model is the choice of an explosion efficiency. One needs to ensute that the yield corresponds with the correct mass of fuel. An efficiency range of 1-10% affects predicted distances to [Pg.151]

TNT equivalency model An explosion model based on the explosion of a thermodynamically equivalent mass of TNT. [Pg.316]

Using the TNT equivalency model, calculate the distance to 5 psi overpressure (equivalent to heavy building damage) of an VCE of 10 short tons of propane. Data [Pg.153]

FIGURE 3.7. Logic diagram for the application of the TNT equivalency model. [Pg.150]

The distance-dependent pressure was calculated using the TNT equivalent model of Sect. 10.6.3.1. A yield factor of 20 % was assumed. The use of curve no. 7 of the multienergy mode, whose application is recommended in [80], does not lead to substantially different results. Pressure and conditional probability of death as functions of the distance on the ground are shown in Fig. 10.46. [Pg.582]

The problem with the TNT equivalency model is that litde, if any, correlation exists between the quantity of combustion energy involved in a VCE and the equivalent weight of TNT required to model its blast effects. This result is clearly proven by the fact that, for quiescent clouds, both the scale and strength of a blast are unrelated to fiiel quantity present. These faaors are determined primarily by the size and nature of the partially confined and obstructed regions within the cloud. [Pg.141]

All of the methods (except the TNT equivalency) require an estimate of the vapor concentration— this can be difficult to determine in a congested process area. The TNT equivalency model is easy to use. In the TNT approach a mass of fuel and a corresponding explosion efficiency must be selected. A weakness is the substantial physical difference between TNT detonations and VCE deflagrations. The TNO and Baker-Strehlow methods arc based on interpretations of actual VCE incidents—these models require additional data on the plant geometry to determine the confinement volume. The TNO method requires an estimate of the blast strength while the Baker-Strehlow method requires an estimate of the flame speed. [Pg.151]

Explosion blast wave largely on the basis of observed explosions, TNT equivalent model (vid. Sect. 10.6.3.1) [Pg.616]

It is obvious that smaller pressure values are obtained than with the TNT equivalent model, if a yield factor of 0.2 is used there. [Pg.543]

According to [66] the distance-dependent side-on peak overpressure in the far fleld (Sachs scaled distance according to Eq. (10.167) R > 2) can be calculated using the TNT equivalent model (vid. Sect. 10.6.3.1). For the near fleld the following relationship should be used (vid. [2]) [Pg.554]

Applying Eq. (10.176) to the near field, different expansion energies of the BLEVEs only affect the radius of the near field. In order to illustrate the different impacts, the results of the application of the TNT equivalent model (cf. Example 10.25) to the present problem are shown in Figs. 10.39 and 10.40. [Pg.558]

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