Introduction to Explosions and Explosion Safety. Instructor: Prof. K. Ramamurthi, Department of Mechanical Engineering, IIT Madras. Starting with the definition of the word explosion, the conditions for which disruption of things at the site of the explosion would occur and examples of the different categories of explosions are discussed. The mechanism of formation of shocks and blast waves are investigated and predictions for a blast wave using the Buckingham Pi theorem are given. The equation for a shock Hugoniot is derived from the conservation equations and the jump in pressure, temperature, density across a constant velocity shock wave is calculated. The impulse and overpressure across a blast wave is thereafter modeled and the scaling laws arrived at for determining overpressure and impulses. Explosion length is introduced as an appropriate scaling parameter. Since the energy release rates must be fast enough to drive an explosion, methods of predicting energy release and energy release rates are dealt with. Induction time is defined and a long induction time or equivalently a high value of activation energy is seen to be essential for an explosion to occur.