The aim of this information is to inform the reader about the variety of explosions that exist & to give a visual framework for animating them. The article has been researched from many places on the Internet and is here purely as animation reference.
In order to animate an explosion appropriately we need to ask ourselves questions about its physical nature. We need to decide what the type of explosion is, what materials create the explosion, what fuels it, what is the trigger or initiator? These answers will help us decide why certain things happen and in what sequence.
TYPES OF EXPLOSION
Explosions can be natural or artificial - simply defined as a sudden release of energy. This release produces a sudden expansion of the material accompanied by large changes in pressure, typically with a flash or loud noise, which is called the explosion. Explosions cause pressure waves in the local medium in which they occur. These pressure waves are called deflagrations if they are subsonic and detonations when supersonic. An example would be gunpowder in a firearm or fuel in an internal combustion engine. Deflagrations are easier to control than detonations - when the goal is to move an object (a bullet in a gun, or a piston in an engine) with the force of the expanding gas.
NATURAL EXPLOSIONS
One of the smallest natural explosions are between interactions of fluids, the details high interactions of these impacts are made visible using high-speed photography.
Volcanic explosions
One of Natures largest explosions comes from volcanic processes. These can take the form of Volcano's, Geysers, Underwater Vents and Earthquakes.
Geysers are hot springs that erupt fountains of scalding water and steam on a regular basis. These occur due to groundwater heated to its boiling point in a confined space. A slight decrease in pressure or an increase in temperature will cause some of this water to boil, then the resulting steam forces overlying water up through the conduit. This loss of water further reduces pressure within the conduit system, and most of the remaining water suddenly converts to steam and erupts to the surface.
Steam explosions (above) often occur when lava enters the sea.
A Volcano develops when magma rises near the Earths surface & occupies an underground chamber. Magma in the chamber is forced upwards and flows out from a vent as lava. Explosive volcanic eruptions occur when the rising magma accumulates large amounts of dissolved gas. The reduction of pressure as the magma rises causes the gas to bubble out of the solution, this results in a rapid increase in volume. People imagine volcanos blasting huge plumes of smoke and fire but in reality the smoke consists of vast volumes of fine dust, mingled with steam and sulphurous vapors. What appear to be flames is in fact the glare from the erupting materials glowing due to their high temperature. This glare reflects off the clouds of dust and steam resembling fire.
Lava
There are three main forms of Lava; 'A'a, Pillow lava & Pahoehoe. 'A'a pronounced 'ah-ah' (see below) is a Hawaiian term for lava flows that have a rough rubble surface composed of broken lava blocks called clinkers. The clinkery surface actually covers a massive dense core, which is the most active part of the flow. As lava in the core travels down the slope, the clinkers are carried along on the surface.
Pillow lava is a variety of rock formed when the lava emerges from an underwater volcanic vent. It forms mounds of elongate lava 'pillows' formed by repeated oozing and quenching of the hot basalt. A glassy crust forms around the newly extruded lava, forming an expanded pillow. Pressure builds until the crust breaks and new basalt extrudes like toothpaste, forming another pillow and so on.
Pahoehoe (far left) is another Hawaiian term for basaltic lava that has a smooth, hummocky, or ropy surface. A Pahoehoe flow typically advances as a series of small lobes and toes that continually break out from a cooled crust.
