explosions lecture 1

what did R WHITE define an explosion as

sudden and violent release of physical or chemical energy accompanied by emission of light heat and sound

what did the chambers of science define an explosion as

rapid increase of pressure in confined space caused by occurance of exothermic chemical reactions where gases are produced in large amounts

what is the overpressure equation

pV = nRT

what is the nuclear equation

E = mc²

what is the chemical equation

deltaG = deltaH - TdeltaS

what is an explosive

energetic material

as not all expolsions are casued by energetic material what else can casue an explosion

external oxidant

whats an example of an external oxidant

02

what does energetic material have that makes it explode

its own oxidant

what are the 2 types of energetical material

individual or mixtures

what is an example of a mixture explosive

ANFO

whats and example of an individual explosive

TNT

what 4 gases are produced by TNT

carbond dioxide and monoxide nitrogen water vapour

what does ANFO stand for

ammonium nitrate oxidiser fuel oil reductant

what are the 2 categories of explosions

primary and secondary

what is a primary explosive

sensitive to shock heat and electricity

what is a secondary explosive

contact insensitive and needs small amount of primary explosive to detonate

what are 2 explosives

low explosives and high

what do low explosives do

deflagrate

what do high explosives do

detonate

what are low explosives used as

propellants

what are 3 examples of a low explosive

gunpowder, fuel, firewoks

hat are 3 examples of high explosives

TNT, RDX, nitroglycerine

what does the chemical reaction in a high explosive create

supersonic shock wave

what id deflagration

rapid oxidation reaction generating low intensity pressure wave of moving gases

what does subsonic mean

slower than speed of sound

is deflagration supoersnoic or subsonic

subsonic

what is the deflagration equation

da/dt = r A p

what is da/dt

rate of bruning

what is r

burn rate constant w

hat is A

area

what is p

density

how do you calculate the burn rate constant

r = B P^a

what is B

burn rate coefficient

what is P

pressure

what is a

pressure index

what is burn rate proportional to

area and pressure

what does burnr ate being related to area and pressure assume

constant density

as the surface area and confinement of an explosive increases will the burn rate increase or decrease

increase

what is detonation

process of subsonic combustion where shock wave is propagated froward due to energy release in reaction zone behind it

how high will 1kg or RDX like a 1kg block

500 km