Lumped Parameter Analysis of Bridge Wire in an Electro Explosive Device of a Power Cartridge for Water-Jet Application: A Case Study

In an armament system an electro-explosive device (EED) essentially converts electrical energy into heat which further initiates the explosive train with its accompanying temperature rise. The first function of an EED in a power cartridge is to provide adequate electrical current to cause ignition of the highly sensitive explosive i.e. lead styphnate. The electrical current accomplishes ignition by heating the bulb of lead styphnate which produces enough heat to cause the booster to ignite. The booster which is in the immediate vicinity augments the ignition of the propellant further. The igniter must be held firmly in place with the booster in the tube. Understanding of the initiation of explosives using a bridge wire in EEDs is important for engineers, designers and scientists to develop new theories. In this research article, theoretical and experimental work has been reported pertaining to bridge wire devices in power cartridges for water-jet applications. The objective of the present research work is to use lumped parameter analysis of a bridge wire in an electro explosive device of a power cartridge for water-jet application. A lumped parameter theory is proposed for the analysis of EEDs. A time constant of 3.35 s has been determined using the lumped parameters. The Biot number is less than 0.1 indicating that transient phenomenon is applied.