Burning Rate Coefficients

1) The propellant burns in terms of Piobert s Law which suggests that the propellant burns in parallel layers (layer by layer) from the exposed surface in a direction perpendicular to the surface. As a natural consequence, it tends to retain its original shape till it is consumed. 

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Burning Rate, and Burning Rate Coefficient. See Vol 2, p B359-R... 

The major ballistic performance parameters of a gun propellant are its energy expressed in terms of force constant and burning rate coefficients a, P and ]. 

The way in which a given propellant charge behaves in respect of its mass burning rate during combustion under adiabatic conditions is called vivacity . It is also experimentally determined by CV and given by the ratio P/D where p = linear burning rate coefficient and D = propellant web size. 

The rate at which the surface of the composition burns, linear burning rate , can be calculated using Equation 3.1, where r is the linear burning rate in mm s-1, P is the pressure at the surface of the composition at a given instant, fi is the burning rate coefficient and a is the burning rate index. 

Burning Rate Coefficient, sometimes designated as Burning Rate Constant It is the interior baiiistics parameter "a in the soiid-propeiiant linear burning rate formula r= apn, where r is... 

Burning Rote Constant Same as Burning Rate Coefficient... 

Burn rate coefficient 2xBL BL None None 0.3 16.9... 

ADN and compositions of ADN have been shown to be able to undergo self-sustained combustion with higher burn rates than the commonly used oxidizer AP. A basic study showed that the bum rate for compressed ADN was 7.4 mm/s at the sub-atmospheric pressure of 0.2 MPa and 54 mm/s at 6 MPa. Since ADN has a surplus of oxygen, its burn rate increases if a carbon source is added. The low-pressure burning is then expanded down to 0.02 MPa. The burn rate for a mixture of ADN and paraffin in the ratio 90 10 has been determined to be 50 mm/s at 7 MPa with a burn rate coefficient of 0.8 and a flame temperature of 2960 [17]. 

Tensile yield strength, 103 lb in-2 Thermal Burning rate, mm min Coefficient of linear thermal expansion, 10 °C 50-90 0.5-2.2 50-90 50-80 50-60 10-13 Self- extinguishing 40-55 46... 

Modification of the burning rates, pressure exponents, and temp coefficients of burning rate of the fluorocarbon composites has been accomplished with copper, lead, tin, sodium, ammonium and potassium fluoborates sodium, potassium, lithium, lead, copper and calcium fluorides potassium and ammonium dichromate lead and zinc stearate cesium carbonate potassium and ammonium sulfate copper chromite oxides of magnesium, copper and manganese boron zinc dust and carbon black (Ref 75)... 

Temp coefficient of burning rate at constant pressure, op = (3finBR/3T)p... 

Turbulent mass burning rate versus the turbulent root-mean-square velocity by Karpov and Severin [18]. Here, nis the air excess coefficient that is the inverse of the equivalence ratio. (Reprinted from Abdel-Gayed, R., Bradley, D., and Lung, F.K.-K., Combustion regimes and the straining of turbulent premixed flames. Combust. Flame, 76, 213, 1989. With permission. Figure 2, p. 215, copyright Elsevier editions.)... 

Three parameters are generally evaluated the mass burning rate (evaporation), the flame position above the fuel surface, and the flame temperature. The most important parameter is the mass burning rate, for it permits the evaluation of the so-called evaporation coefficient, which is most readily measured experimentally. 

The previous developments also can be used to determine the burning rate, or evaporation coefficient, of a single droplet of fuel burning in a quiescent atmosphere. In this case, the mass fraction of the fuel, which is always considered to be the condensed phase, will be designated mr, and the mass fraction of the oxidizer ma. m0 is the oxidant mass fraction exclusive of inerts and i is... 

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