Wyniki wyszukiwania - BazTech

1

Numerical Simulation of the Deflagration to Detonation Transition in Granular High-Energy Solid Propellants

Zhen Fei, Wang Liqiong, Wang Zhuoqun

Central European Journal of Energetic Materials

|

2019

|

Vol. 16, no. 4

504--519

EN

This paper describes a one-dimensional code developed for analyzing the two-phase deflagration to detonation transition (DDT) phenomenon in granular high-energy solid propellants. The deflagration to detonation transition model was established based on a one-dimensional two-phase reactive flow model involving basic flow conservation equations and constitutive relations. The whole system was solved using a high resolution 5th-order WENO (Weighted Essentially Non-Oscillatory) scheme for spatial discretization, coupled with a 3rd-order TVD Runge-Kutta method for time discretization, to improve the accuracy and prevent excessive dispersion. An inert two-phase shock tube problem was carried out to access the developed code. The DDT process of high-energy solid propellants was simulated and the parameters of detonation pressure, run distance to detonation and time to detonation were calculated. The results show that for a solid propellant bed with solid volume fraction 0.65, the run distance to detonation was about 120 mm, the detonation induced time was 28 μs, and the detonation pressure was 18 GPa. In addition, the effects of solid volume fraction (φs) and pressure exponent (n) on the deflagration to detonation transition were also investigated. The numerical results for the DDT phenomenon are in good agreement with experimental results available in the literature.

2

Evaluation of Strontium Ferrite (SrFe12O19) in Ammonium Perchlorate-based Composite Propellant Formulations

Jain Sunil, Kshirsagar Dhirendra R., Khire Vrushali H., Kandasubramanian Balasubramanian

Central European Journal of Energetic Materials

|

2019

|

Vol. 16, no. 1

105--121

EN

In the present work, various propellant compositions were prepared by incorporating strontium ferrite (SrFe12O19) in an ammonium perchlorate (AP), aluminium powder and hydroxyl-terminated polybutadiene (HTPB) based standard composite propellant. The compositions were then studied by assessing the effect of the SrFe12O19 content on the propellant slurry viscosity, and the mechanical and ballistic properties. The results showed that as the percentage of SrFe12O19 in the propellant was increased, the end of mix (EOM) slurry viscosity, tensile strength and E-modulus increased, while the elongation decreased. The ballistic properties data revealed that the burning rate of the propellant composition containing 1.0% SrFe12O19 was enhanced by around 15% (at 6.86 MPa) compared to the standard composition burning rate.

3

Studies on the Effect of Nano-MnO2 in HTPB-based Composite Propellant Formulations

Kshirsagar D. R., Jain S., Bhandarkar S., Vemuri M., Mehilal

Central European Journal of Energetic Materials

|

2017

|

Vol. 14, no. 3

589--604

EN

Various propellant compositions were prepared incorporating fully characterized nano-sized manganese dioxide, from 0.25 wt.% to 1.0 wt.%, in HTPB/AP/Al-based composite propellant formulations having 86 wt.% of solid loading, and its effects on the viscosity build-up, thermal, mechanical and ballistic properties were studied. The findings revealed that on increasing the percentage of nano-MnO2 in the composition, there was an increase in the end of mix viscosity, the modulus and tensile strength, while the elongation decreased accordingly. The data on the thermal properties revealed a reduction in the decomposition temperature of ammonium perchlorate (AP) as well as of the formulations based on it. The data on the ballistic properties revealed that there is an enhancement in the burning rate from 6.11 mm/s (reference composition) to 7.54 mm/s at 6.86 MPa (a 23% enhancement in the burning rate) and an increase in the pressure exponent from 0.35 (reference composition) to 0.42 with 1.0 wt.% nano-MnO2.

4

Studies on Aluminized, High Burning Rate, Butacene® Based, Composite Propellants

Ghosh K., Behera S., Kumar A., Padale B. G., Deshpande D. G., Kumar A., Gupta M.

Central European Journal of Energetic Materials

|

2014

|

Vol. 11, no. 3

323--333

EN

This paper reports on a Butacene® based composite propellant with high burning rate. The effect of replacing HTPB with Butacene® on the physical, mechanical and ballistic properties, and sensitivity towards impact and friction, has been studied. The ballistic properties were evaluated as burning rates at various pressures (7-11 MPa), pressure exponents, ignition temperatures etc. As expected, a remarkable enhancement in burning rate at low pressures was observed with increasing percentage of Butacene®. Comparatively lower n-values were observed for compositions containing Butacene® than for HTPB based propellants. The sensitivity of Butacene® based compositions, in terms of impact and friction, was found to be increased with an increasing percentage of Butacene®.