HMX-GAP composite propellant

Fig.4.17 Specific impulse, adiabatic flame temperature, and molecular mass of combustion products for HMX-GAP composite propellants.

Fig. 4.18 Mole fractions of combustion products from HMX-GAP composite propellants.

Fig. 7.39 Burning rates and flame stand-off distances of non-catalyzed and catalyzed HMX-GAP composite propellants.

A typical super-rate burning of an HMX-GAP composite propellant is shown in Fig. 7.43. The lead catalyst is a mixture of lead citrate (LC PbCi), Pb3(C5H50y)2-x H20, and carbon black (CB). The composition of the catalyzed HMX-GAP propellant in terms of mass fractions is as follows gap(0.194), hmx(0-780), lg(0 020), and, q 0.00G). GAP is cured with 12.0% hexamethylene diisocyanate (HMDI) and then crossUnked with 3.2 % trimethylolpropane (TMP) to... 

Fig. 7.43 Effect of catalyst on superrate burning of HMX-GAP composite propellant.

Fig. 7.45 Flame photographs of catalyzed and non-catalyzed HMX-GAP composite propellants ...

The thermodynamic potential defined by Tg/Mg is approximately the same for both TAGN-GAP and HMX-GAP composite propellants. 

The physicochemical properties of propellants with the compositions hmx(0-4), Ihmx(0-6), and hmx(0-8) are shown in Table 7.3. Since the energy density of HMX is higher than that of GAP, the adiabatic flame temperatures of HMX-GAP propellants increase with increasing hmx-... 

The polymeric binders used for nitramine composite propellants are similar to those used for AP composite propellants, i. e. HTPB, HTPE, and GAP. The combustion performance and the products of HMX composite propellants are shown in Figs. 4.17 and 4.18, respectively. Here, the binder mixed with the HMX particles is GAP, as in the AN-GAP propellants shown in Fig. 4.16. Though the maximum Tf and f, are obtained at (HMX) = 1.0, the maximum HMX loading is less than 0.80for practical HMX-GAP propellants, at which fp = 250 s and 7 =... 

Figure 7-22. Burning rate and flame standoff distance of non-catalyzed and catalyzed GAP-HMX composite propellants.

The relative shock sensitivities of explosive compositions are commonly assessed by means of gap tests. In these tests, the shock from a standard donor explosive is transmitted to the test explosive through an inert barrier (the so called gap ). The shock sensitivity of the test explosive is characterized by the gap thickness for which the probability of detonation is 50%. In reference 26, the Los Alamos standard gap test and the Naval Ordnance Laboratory (NOL) large scale gap test were modeled using the 2DE code with Forest Fire burn rates. The Los Alamos gap test uses Dural for the inert barrier while the NOL gap test uses Plexiglas. The test explosive is unconflned in the Los Alamos gap test. In the NOL gap test the test explosive is confined with steel. The model showed good agreement between the calculated and experimental gap test values for PBX-9404, PBX-9502, Pentolite, Composition B, and an HMX based propellant, VTQ-2. 

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