Gases expanding

Earlier ehapters explained tliat air separation expanders are mrbines that expand gases in two steps, using primary and seeondary gas expansion deviees. Inlet guide vanes (or inlet nozzles) are the primary expansion deviee. Their funetion is to eonvert almost half of... 

Gas turbines differ from conventional internal-combustion engines in the manner in which the expanded gases are employed. The principle of operation is to direct a stream of hot gases against the blading of a turbine rotor. As shown in Figures 16-6 and 16-7, the gas turbine consists of... 

The difference between this equation and the equation for ex,wo that the internal energy of the air that is displaced by the expanded gases is taken into account. Note that, when y, is equal to yo, Eq. (6.3.13) is equivalent to Eq. (6.3.2). Aslanov and Golinskii advocate the use of the energy E bx.ag the energy of the explosion. They claim that this gives a better correlation with numerical calculations and with experiments. 

The mechanism for rotating the wheels in a car or truck has its origin in pistons in the engine that are forced to move by expanding gases in the cylinders. The expanding gas is a result of igniting a mixture of... 

Hydraulic high-pressure failures also give relatively small tears compared to pneumatic failures, which are destructive. Rapidly expanding gases give large tears and can propel missiles, drums, and vessels great distances. 

Missiles - items thrown by the blast of expanding gases might cause damage or escalation. 

Sodium azide (NaN ) is an explosive salt of nitrogen that produces large quantities of gas upon its explosion. This quality has made it ideal as the chemical contained in automobile air safety bags. When triggered it explodes immediately, producing the expanding gases that fill the bag. 

However, in practice, the energy of the hot combustion products of the gunpowder is never fully utilised in providing forward motion to the shell. Losses occur unavoidably in several ways - as radiation as residual energy of motion of the partially expanded gases as leakage of gas around the shell and as wave motion (noise) in the surrounding atmosphere. 

Casting of composite propellants is usually conducted under reduced pressure to eliminate air or other gases from the liquid propellant mix. Any voids caused by expanded gases will remain fixed in the propellant grain if gelation occurs before the vacuum is released. Hence, the vacuum must be released after volatiles are removed but before gelation... 

Rapidity of reaction distinguishes an explosive reaction from an ordinary combustion reaction and therefore, an explosive reaction takes place with great speed. Unless the reaction occurs rapidly, thermally expanded gases are dissipated in the medium slowly, so that no explosion results. Again an example of wood or coal fire makes it clear. When a piece of wood or coal bums, there is an evolution of heat and formation of gases, but neither is liberated rapidly enough to cause an explosion. 

When a high expl detonates the effects may be divided into several phases (Ref 2) a)The phase in which the expanding gases cause the case to swell and fragment is called the Frag ... 

---