Internal explosions and their effects on humans

Abstract

This paper concerns indoor explosions and the impact of blasts on humans. The standard approach from the engineering and medical communities is that blast overpressure is the criterion that determines trauma and injury. However, this study shows that the wind force generated behind the blast can affect humans more significantly, even for relatively low blast overpressures. Although the present findings also apply to external explosions, we chose the indoor case as this is a more complex problem. We present high-order simulations for an explosion equivalent to 2.5 lbs of trinitrotoluene in a simplified indoor environment comprising three rooms and a corridor. The explosion magnitude could correspond to a malicious act, such as someone carrying a rucksack with the above explosive. The study reveals that the force generated can be up to 60 times the human's weight, even in the spaces adjacent to the room where the explosion occurred. The blast effects will be fatal for humans in the room where the explosion occurs. The impact on human organs, such as the lungs, brain, and gastrointestinal system, will vary in the adjacent spaces. The likelihood of primary injury increases from the repeated shockwaves due to their continuous reflections of the walls, impacting the lungs and gastrointestinal tract significantly and causing eardrums to burst and brain hemorrhage. Secondary blast injuries will occur due to the debris and high airspeeds behind the blast. Corridors and locations facing the doors are particularly dangerous. The simulations show a common asymptotic decay behavior of the wind force and blast overpressure across rooms at later times. The study concludes that forces resulting from the high airspeeds that develop are likely to cause greater injury than the blast overpressure itself.