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White smoke trail

HCl molecules form visible white fog when water vapor is present in the atmosphere. An HCl molecule acts as a nucleus, becoming surrounded by HjO molecules, which forms a fog droplet large enough to be visible. When the combustion products of an AP composite propellant are expelled from a rocket nozzle into the atmosphere, a white smoke trail is seen as a rocket projectile trajectory whenever the relative humidity of the air is above about 40%. Furthermore, if the temperature of the atmosphere is below 0 °C (below 273 K), the HjO molecules generated among the combustion products form a white fog with the HCl molecules even if the relative humidity is less than 40 %. Thus, the amount of white fog generated by the combustion of an AP composite propellant is dependent not only on the humidity but also the temperature and pressure of the atmosphere. [Pg.353]

AP composite propellants without aluminum particles are termed reduced-smoke propellants and are employed in tactical missiles to conceal their launch site and flight trajectory. No visible smoke is formed when the relative humidity of the atmosphere is less than about 40%. However, since high-frequency combustion oscillation tends to occur in the combustion chamber in the absence of solid particles that serve to absorb the oscillatory energy, a mass fraction of 0.01-0.05 of metallic particles is still required for the reduced-smoke propellants. These particles and/or their oxide particles generate thin smoke trails. The white smoke trail includes the white fog generated by the HCl molecules and the condensed water vapor of the humid atmosphere. [Pg.354]

Thus, AP is a valuable oxidizer for formulating smokeless propellants or smokeless gas generators. However, since the combustion products of AP composite propellants contain a relatively high concentration of hydrogen chloride (HCI), white smoke is generated when they are expelled from an exhaust nozzle into a humid atmosphere. When the HCI molecules diffuse into the air and collide with H2O molecules therein, an acid mist is formed which gives rise to visible white smoke. Typical examples are AP composite propellants used in rocket motors. Based on experimental observations, white smoke is formed when the relative humidity exceeds about 40 %. Thus, AP composite propellants without any metal particles are termed reduced-smoke propellants. On the other hand, a white smoke trail is always seen from the exhaust of a rocket projectile assisted by an aluminized AP composite propellant under any atmospheric conditions. Thus, aluminized AP composite propellants are termed smoke propellants. [Pg.360]

The tactical uses of screening smokes and the means of producing them are only of limited interest to the pyrotechnician, since his devices are unable to produce enough smoke except in a relatively small area. However, the second purpose of smokes—the emission of smoke clouds or trails as a means of signaling—is well served by pyrotechnic grenades, pots, or bursts, especially since various bright colors can be achieved beside white smoke. [Pg.148]

Crawford, Cook, and Whiting, Statistics, "Procurement, p. 21. (2) J. C. Driskell, W. K. Ginman, and M. A. Zizmor, Colored Smokes—Colored Smoke Trail Bombs E13, E13R1, and E13R2. TDMR 861, 3 Aug 44. (3) CWTC Item 1132, Standardization of Bomb, Smoke, Colored Streamer, M87, 31 Aug 44. [Pg.223]

Sparse, moody, smoking around them. Colourless wasn t the word, with the old-fashioned artistry of a black and white photographer she had stripped it all back to a desolate beauty. It was all light and shade, a trail along wide horizons and burning skies then sudden tunnels, bass line like a python weaving beneath the canopy of percussion. Music so spacious you could stretch right out inside it and still not reach the furthest extremities. [Pg.366]

Suddenly, the imthinkable happened. Only 73 seconds into the flight, the spacecraft exploded and burst into flames. Television cameras captured this disaster as a bright flash in the sky followed by a white trail of smoke. The tragedy was replayed numerous times for viewers worldwide. [Pg.390]


See other pages where White smoke trail is mentioned: [Pg.354]    [Pg.354]    [Pg.555]    [Pg.635]   
See also in sourсe #XX -- [ Pg.360 ]

See also in sourсe #XX -- [ Pg.360 ]




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