Ignition star

The black dragon composition is pressed into a tin tube and primed with a small igniting star and a piece of black match. The black willow is used in the form of cut stars The anthracene is somewhat expensive, and half the quantity can be replaced by naphthalene v/ith the same effect. There are three requirements for black smoke stars producing pretty smoke no remaining fire and safety in manufacturing and handling. 

The above compositions nearly satisfy all the three, but it is quite difficult to ignite them. Therefore in this case of the dragon it is necessary to use an ignition star as a first fire composition and in the case of the black willow stars to coat them first with the silver wave composition(l5 2(3)c) and then with the chrysanthemum 8, 6 and black powder one after another. 

When helium fusion comes to an end at the centre of the star, its carbon/ oxygen core contracts and the temperature rises. At a temperature slightly below 1 billion K, carbon is ignited. 

If a star is not massive enough for helium fusion to ignite, it simply exhausts its hydrogen reserves and stops evolving. As a white dwarf, it then joins the rest of its kind in the great stellar cemetery. 

Fig. 13.18 Combustion instability of a six-pointed-star grain, showing DC and AC components of pressure and the cross-section of the grain (1) before ignition and (2) after burning interruption.

Fig. 14.19 shows a typical set of pressure versus time curves obtained from tests on a rocket motor. When the I/D ratio defined in Fig. 14.19 is increased, the head-end chamber pressure is increased drastically immediately after the ignition stage. These grains are seven-pointed-star-shaped neutral-burning grains (diameter D = 114 mm), and are made of an AP-Al-CMDB propellant with the composition nc(0-25), ng(0-31), Ita(0-08), ap(0-27), and ai(0 09). The ratio of the initial burning surface area (Ayg) to the nozzle throat area (Aj), = AygjAp and the ratio of the... 

A length of match or a pressing of delay fuse connects the rocket motor with the payload so that when the motor burns-out the fuse is lit and communicates with an ejection charge of gunpowder which ignites and ejects the stars. 

Almost simultaneously the second fuse is lit by the top break explosion, the burning of this fuse being timed to ignite the gunpowder in the middle compartment just as the red stars are burning out. 

In this way the amber stars are ignited and ejected while the third, and final, delay fuse is also burning. 

Titanium is therefore an important ingredient in fountain compositions. It is characterised as a non-volatile metal with non-volatile oxides. The particles are easily ignited, even in the form of large flitters , and once ignited they grow progressively brighter and finally explode in a spectacular star formation. 

---