Air burst

Figure 4.17. Side-on blast peak overpressure due to (a) a TNT surface burst. (Kingery and Panill 1964) and (b) a free-air burst of TNT (Glasstone and Dolan 1977).

Figure 4.19. Diameters of side-on overpressure circles for various explosive yields (1 ton 2000 lb) (based on free-air bursts).

Free-Air Bursts of Gas-Filled, Massless, Spherical Pressure Vessels... 

This subject has received little attention in the context of pressure vessel bursts. Pittman (1976) studied it using a two-dimensional numerical code. However, his results are inconclusive, because the number of cases he studied was small and because the grid he used was coarse. Baker et al. (1975) recommend, on the basis of experimental results with high explosives, the use of a method described in detail in Section 6.3.3. That is, multiply the volume of the explosion by 2, read the overpressure and impulse from graphs for firee-air bursts, and multiply them by a factor depending on the range. 

This energy measure is equal to Brode s definition of the energy, multiplied by a factor 2. The reason for the multiplication is that the Brode definition applies to free-air burst, while Eq. (6.3.15) is for a surface burst. In a fiee-air burst, explosion energy is spread over twice the volume of air. 

Blast parameters for surface bursts of gas-filled pressure vessels have not been investigated thoroughly. Parameters presently used are derived from investigations of free-air bursts. 

This charge is most effective when an air burst... 

Figure 26. Airblast Parameters vs. Scaled Distance for a TNT Spherical Air Burst. (Ref. 31)...

Kingery, C. N., and Bulmash, G., "Airblast Parameters from TNT Spherical Air Burst and Hemispherical Surface Burst," Ballistic Research Laboratory Technical Report ARBRL-TR-02555, Aberdeen Proving Ground, MD., 1984. 

Addnl Refs A) Collective, "Air Burst in Blast Bombs . A Compilation of Papers Presented at NDRC Div 2 Symposium, OSRD 4923 (1945) B) Collective, "Underground Explosion Test Program , Final Rept, Vol II, "Rock , Engineering Research Associates, Division of Remington Rand Inc, 30 April 1953 (Conf) (Not used as a source of information) C) G.R. Pickett, "Seismic Wave Propagation and Pressure Measurements Near Explosions , Quarterly of the Colorado School of Mines 50(4) (Oct 1955) D) W.E. Deal, "Shock Hugoniot in Air , JApplPhys 28, 782-84(1957) E) Dunkle s Syllabus, Session 26, 23 Apr 1958, pp 313-18 F) Dunkle s Syllabus, Suppl to Section 26 (1961) G) Dunkle, private communication,... 

Not only the above "air-burst" but "proximity-fuze too, were envisioned by Lieut Moor. He proposed to equip shells and underwater mines (called in his time "torpedoes ") with such fuzes. His proximity fuze was not described in the article of Eichberg (Ref 33a), but probably was in one of the official reports addressed to the Navy... 

M31 and Tetryl pellet booster. Designed for use with the fragmentation (butterfly) bomb, it can be set either for "GROUND " action (by impact) or for "AIR" burst, preset for delays 10, 20, 30, 40, 50 or 60 minutes after arming. Arming takes place after 50 -ft of air travel... 

Accidental Release (Low Altitude, Hard Surface) (206) Muzzle Impact Safety (Projectile) (207) Impact Safe Distance (Projectile) (208) Missile Pull Off from Aircraft on Arrested Landing) (209) Time-to-Air Burst (211) Field Parachute Drop (212) and Air Delivery, Simulated (Parachute Drop) (T213) Class 300. Explosive Component Output Measurement by Steel Dent) (301.1) Detonator Output Measurement by Lead Disc (302) and Explosive Component Output Measurement by Aluminum Dent (303)... 

A 40 lb air-burst bomb developed by the British was filled with yellow phosphorous and... 

Air-burst effects of the blast from bpmbs and small charges 1 All 6 >... 

Air Burst. Particles produced by condensation are spherical, and range in size from about 0.01/x to perhaps 20/x in diameter. The particles are metal oxides and exhibit densities in the range of the metal oxides of the condensable materials vaporized by the detonation. Radionuclide partitioning can be described (2) by a series of equations of the form... 

Ce, 147Nd, and radionuclides with gaseous precursors correlate linearly and have nearly the same correlation parameters as have been observed in air bursts. 

Transient Test Air Bursts Coral Surface Burst Silicate Surface Bursts... 

Come years ago Freiling proposed that the specific activity (activity per unit weight or volume) of individual fission products in nuclear debris, particularly from air bursts, be expressed as an inverse power function of the particle size (2, 3). Thus ... 

The character of the radioactive debris from a land surface explosion is determined largely by the extent of mixing between the extraneous debris injected into the cloud and the fission product radioactivities. Within the early cloud there is a well developed toroidal circulation (5), which is clearly evident in the case of air bursts and large yield surface bursts. In low yield surface explosions it may be obscured quickly by the dirt cloud and by rapid damping of a systematic circulation. 

The air burst simulator (M27A1B1) is used to simulate the airburst of an artillery projectile for high-burst ranging practice... 

If, for example, troops know they have no artillery in the area but suddenly see and hear air bursts in the vicinity, the troops will believe that enemy activity includes artillery after all. The tide of battle could thus be changed merely by simulation of artillery air bursts, perhaps by a very limited force... 

In Figures 2.4 and 2.5, some of the products themselves are fuels, specifically the free carbon, C, and the carbon monoxide, CO. After the burning or detonation reaction is complete, the products may be free to expand into air. As they do this, they may mix with the oxygen in the air, burst into flame, and bum to CO2 when the proper mixture with the air is reached. This second reaction is called a secondary fireball. Such fireballs can also be fueled from other burnable mate-... 

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