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Since the effect of a blast pulse is to generate an aerodynamic pressure pulse, P is the radius of the pressure pulse and T is the duration of the pulse [37]. A P with a radius value of a few centimeters is at times more effective than a P/d ratio, where d is the diameter of the explosive charge. The incident angle of the explosion pulse will also influence the blast-wall pressure. This is because the angle of incidence affects the percussion of the pulse on the target surface, as can be seen in equation (3), where a is a coefficient that depends on the angle of incidence. The value a has been determined by Burlet and co-workers [22] as 312°. The incident angle is a function of the stand-off distance, which is in turn functional of the size of the launch tube.

An important input parameter to the kinetic energy of the pulse is the product of the total impulse (I) and the duration of the pulse (T), as expressed by Weber and Stouffler [44]. I is typically used to calculate the energy of the actual blast and the T parameter is used as a time factor. A time of a few microseconds is sufficient to trigger thermal pressure effects to occur. Thermal effects can be neglected if the mass of the explosive is small [43].

The total impulse is calculated by multiplying the mass of the explosive charge (M) by the velocity of the explosion (V). The equation for the impulse can be expressed by the following equation:

As mentioned previously, the velocity of the blast, 1.2 m·s-1 [45], is assumed to be constant during the calculation, for a specific original stand-off distance [R [46]]. Figure 11. Pictorial representation of the blast wave. d2c66b5586