Blast wave
A pressure disturbance that propagates outward after a sudden release of energy. Its leading shock front compresses and heats the surrounding medium.
Shock wave: A propagating front across which pressure, density, temperature, and flow velocity change abruptly. The blast wave’s leading edge is a shock while its strength remains above the acoustic range.
Pressure: Force exerted per unit area by a fluid or surface. A blast wave is identified by its rapidly changing pressure field.
Blast injury: Physical harm caused by pressure waves and related effects of an explosion. The pressure history and impulse of a blast wave help explain primary blast injuries.
Trinity test: The first nuclear weapons test, conducted in New Mexico on July 16, 1945. Its expanding fireball and pressure wave became a landmark case for studying nuclear blasts.
Impulse (mechanics): The time integral of force, equal to the change in momentum. Blast loading depends not only on peak pressure but also on how long the pressure acts.
Rankine–Hugoniot conditions: Conservation relations linking fluid states across a shock or other discontinuity. They relate the pressure, density, and velocity changes across a blast wave’s front.
Acoustic wave: A small disturbance that propagates through a medium as sound. Ordinary acoustic waves are weak and nearly linear, unlike a strong blast’s shock front.
Blast-resistant construction: Design of structures to reduce damage from explosive pressure and debris. Engineers use predicted blast loads to size protective walls, windows, and structural connections.
Tunguska event: A 1908 atmospheric explosion over Siberia that flattened a vast area of forest. The airburst produced destructive blast effects without leaving a confirmed impact crater.
Overpressure: Pressure in a fluid above its surrounding ambient pressure. The overpressure profile describes the compressive part of a passing blast wave.