Burning Rate Of Composite Solid Propellants Research Articles

Thermal decomposition and kinetic investigation of AP and AP based composite solid propellant in the presence of nickel ferrite additive

Nanosize nickel ferrite (NiF) with an average crystalline size of 28.6 nm has been successfully synthesized via the co-precipitation method. NiF was found to efficiently reduce the thermal decomposition of ammonium perchlorate (AP) and Composite solid propellants (CSPs) along with an increment in the burning rate of CSPs by 1.6 times. The high-temperature DSC exothermic decomposition peak of AP was decreased by 59.04 °C in the presence of 1% by weight NiF additive. Differential Scanning Calorimeter (DSC) exothermic peak of CSPs based on AP + NiF was decreased by 37.72 °C as compared to that of CSPs based on pure AP. Further, the kinetics parameters of AP and AP + NiF mixture were evaluated using iso-conversional methods. The results indicated that the activation energy the of AP + NiF mixture was increased despite reduction in the thermal decomposition temperature.

Burning Rate Studies: Potassium-Doped Ammonium Perchlorate with Other Burn-Rate Modifiers

Iron oxide and copper chromite have been used as burn-rate modifiers of composite solid propellants. In recent times, studies have been reported on potassium-doped ammonium perchlorate and on dry activated charcoal. These have shown an increase in composite solid propellant burning rates. The studies on composite solid propellants using dry activated charcoal have also shown a reduction in the burn-rate pressure index for a composite solid propellant. With this knowledge, experiments are conducted to develop compositions that result in both high burning rates and low burn-rate pressure index of the propellant. In addition to these, the study also reports propellants with dual burn-rate pressure index. The change in the burn-rate pressure index is from 0.2 to 0.65 in one of the propellants. These could be very useful in that the same grain can act as boost and sustain grain depending on the combustion chamber pressure. With the addition of different burn-rate modifiers, the pressure at which the change in burn-rate pressure index is observed shifts. This could be a very useful tool for propellant designers. It was observed that, with the use of activated charcoal along with potassium-doped ammonium perchlorate, the burn-rate pressure index was brought down from around 0.65 to 0.38, whereas the burn rates were still higher (60%) than the base propellant.

Activated charcoal: as burn rate modifier and its mechanism of action in non-metalized composite solid propellants

Modification of composite solid propellant burning rates becomes a requirement based on the necessities of a mission. Literature discusses about various burn rate modifiers which can modify the burning rates effectively. This paper attempts to understand the behavior and mechanism of (dry) activated charcoal (a recently reported burn rate modifier) in composite solid propellant combustion. Extensive experimental studies are performed to achieve this objective. Effects of activated charcoal are studied on the individual components (fuel and oxidizer) of a composite solid propellant. Its behavior when present at various locations in a sandwich propellant and the quenched surface structures these sandwich propellants is also studied. These studies are further extended to composite propellants as well. From these studies, it is concluded that activated charcoal acts on the primary diffusion flame and enhances the binder melt flow over the surface. The unique features observed with activated charcoal (enhancement in burning the rates is observed only at low pressures and burn rate pressure index reduced) are justified with the proposed mechanism and site of its action. Understanding the mechanism of activated charcoal provided an opportunity to tailor a propellant composition, with activated charcoal coated on ammonium perchlorate, which exhibited very high burning rates (17.34 mm/s at 70 bar) and a near plateau burning (n ~0.08) in the pressure range of 20–70 bar. Also, this paper proposes a mechanism, as to what causes a propellant to have a relatively larger binder melt flow and consequently lower n has been answered.

Enhancing Composite Solid Propellant Burning Rates with Potassium Doped Ammonium Perchlorate—Part 2

This paper reports the development of a nonaluminized composite solid-propellant formulation with high burning rates. To achieve high burning rates, potassium (described in the literature as an impurity) has been doped into ammonium perchlorate. It is seen that beyond a potassium content of 0.19% the increase in the burning rates of a composite propellant is not significant. A high-burn-rate pressure index at high pressures and the dual slope has been observed with the potassium doped ammonium perchlorate in a composite solid propellant even with the use of only fine sized ammonium perchlorate particles. These features have been explained through surface scanning electron microscope pictures of quenched propellant samples.

Enhancing Composite Solid Propellant Burning Rates with Potassium Doped Ammonium Perchlorate-Part I

The objective of this paper is to understand the observed changes in behavior of ammonium perchlorate deflagration characteristics reported in literature, when it is doped with potassium. Successive recrystallization is employed to dope potassium into ammonium perchlorate. This paper, through various recrystallization techniques, conclusively puts an end to doubts regarding the actual process of acquisition of potassium by ammonium perchlorate. It is concluded that the increase in the potassium content in ammonium perchlorate is due to the filter used during recrystallization process. From the experiments conducted to obtain the deflagration rates of ammonium perchlorate, it is observed that potassium doped ammonium perchlorate has higher burning rates and also a higher low-pressure deflagration limit. As potassium doped is within the ammonium perchlorate crystal, thermal conductivity and specific heat values for ammonium perchlorate with various percentages of potassium are obtained. These values are incorporated into the computational studies on ammonium perchlorate. The computational studies performed in this paper are not intended to reproduce the experimental results but to illustrate the various features of the potassium doped ammonium perchlorate deflagration. With these computational studies, the observed burning rate increase and low-pressure deflagration limit increase of ammonium perchlorate with doped potassium are explained.

Synthesis, characterisation and catalytic activity of cadmium cobaltite nanoparticles: part 87

In this paper, we report the synthesis of cadmium cobaltite nanoparticles (CCNs) and their characterisation by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). The particles are spherical in shape and the average particle size is of the order of 20–30 nm. Its catalytic activity was investigated through the thermal decomposition of ammonium perchlorate (AP), composite solid propellants (CSPs), 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one (NTO) and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) using thermogravimetry (TG), TG coupled with differential scanning calorimetry (TG-DSC) and ignition delay measurements. The kinetics of thermal decomposition of AP + CCNs has also been investigated using isoconversional and model-fitting approaches, which have been applied to data for isothermal TG decomposition. The burning rate of CSPs was considerably enhanced by these nanoparticles. The ignition delays and activation energies are found to decrease when CCNs were incorporated in the system. The addition of CCNs to AP led to a shifting of the high-temperature decomposition peak towards lower temperature. All these studies show enhancement in the rate of decomposition of AP, NTO, HMX and CSPs.

Synthesis, characterization of Co–Ni–Cu trimetallic alloy nanocrystals and their catalytic properties, Part – 91

Present approach should find a potential application in preparing ternary alloy nanoparticles as a catalyst. Ternary Co–Ni–Cu nanocrystals (TMNs) have been successfully synthesized via hydrazine reduction procession. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HR-TEM) were employed to study the structural features of the nanomaterials. The resulting material showed a homogeneous alloy structure with an average diameter of 16.4nm. Good composition control and size distribution of Co–Ni–Cu nanocrystals are achieved. It’s catalytic activity was investigated on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellants (CSPs) using thermogravimetry (TG), TG coupled with differential scanning calorimetry (TG-DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP+(Co–Ni–Cu) has also been investigated using isoconversional and model-fitting approaches which have been applied to data for isothermal TG decomposition. TMNs can enhance catalytic activity towards thermal decomposition of AP as compared to Co–Ni and Ni–Cu bimetallic nanoparticles. The ignition delays and activation energies are found to decrease when TMNs were incorporated in the system. The burning rate of CSPs was considerably enhanced by these nanocrystals.

Nanorods, nanospheres, nanocubes: Synthesis, characterization and catalytic activity of nanoferrites of Mn, Co, Ni, Part-89

In this paper, the nanoferrites of Mn, Co and Ni were synthesized by wet chemical method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive, X-ray spectra (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HR-TEM). It is catalytic activity were investigated on the thermal decomposition of ammonium perchlorate (AP) and composite solid propellants (CSPs) using thermogravimetry (TG), TG coupled with differential scanning calorimetry (TG–DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP+nanoferrites have also been investigated using isoconversional and model fitting approaches which have been applied to data for isothermal TG decomposition. The burning rate of CSPs was considerably enhanced by these nanoferrites. Addition of nanoferrites to AP led to shifting of the high temperature decomposition peak toward lower temperature. All these studies reveal that ferrite nanorods show the best catalytic activity superior to that of nanospheres and nanocubes.

Synthesis, characterization and catalytic behavior of Cu nanoparticles on the thermal decomposition of AP, HMX, NTO and composite solid propellants, Part 83

The synthesis of Cu nanoparticles by reducing CuSO4 with hydrazine in ethylene glycol under microwave irradiation, has been described. These nanoparticles have been characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern and X-ray diffraction (XRD) which shows an average particle diameter of 20.3nm. The catalytic activity, of Cu nanoparticles on thermal decomposition of ammonium perchlorate (AP), composite solid propellants (CSPs) using thermogravimetry (TG), differential scanning calorimetry (DSC) have been measured. Results indicate that nanoscale Cu particle lowers the energy of activation for thermal decomposition of AP and CSPs. Activation energy for ignition has also been found to be lowered in case of AP, CSPs, HMX and NTO. The burning rate of CSPs has been found to be enhanced. Isothermal TG data was used to evaluate kinetic parameters by model fitting as well as isoconversional methods and values of activation energy were found to be lowered with Cu nanoparticles.

Preparation, characterization, and catalytic activity of rare earth metal oxide nanoparticles

In present study, a series of rare earth metal oxide (CeO2, Pr2O3, and Nd2O3) nanoparticles have been prepared by sol–gel route using Ce(NO3)3·6H2O, Pr(NO3)3·6H2O and Nd(NO3)3·6H2O, and citric acid as precursor materials. Powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are employed to characterize the size and morphology of the nano oxide particles. The particles are spherical in shape and the average particle size is of the order of 11–30 nm. Their catalytic activity was measured on the thermal decomposition of ammonium perchlorate and composite solid propellants (CSPs) by thermogravimetry (TG), TG coupled with differential thermal analysis (TG–DTA), and ignition delay measurements. The ignition delays and activation energies are found to decrease when rare earth metal oxide nanoparticles were incorporated in the system. Addition of metal oxide nanoparticles to AP led to shifting of the high temperature decomposition peak toward lower temperature and the burning rate of CSPs was also found to enhance. However, E a activation energy for decomposition was also found to decrease with each catalyst.

Nanocobaltite: Preparation, Characterization, and their Catalytic Activity

AbstractMixed transition metal oxides (MTMO) nanoparticles of 3rd‐series (NiCo2O4, CuCo2O4, and ZnCo2O4) were prepared by a co‐precipitation method. These were characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The particle size was found to be in the order of 53.0, 43.4, and 21.2 nm, respectively. The thermolysis of ammonium perchlorate (AP), AP‐HTPB (hydroxyterminated polybutadiene) composite solid propellants (CSPs), and HTPB was found to be catalyzed with MTMOs and the burning rate of CSPs was also enhanced. TG and ignition delay study demonstrated that the higher temperature decomposition (HTD) of AP is catalyzed enormously by these catalysts and CuCo2O4 is the best candidate.

Synthesis, characterization and catalytic activity of CdO nanocrystals

In this paper, we report the synthesis of nanocrystalline cadmium oxide (CdO) and its characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Its catalytic activity was investigated on the thermal decomposition of 1,2,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), ammonium perchlorate (AP), hydroxyl terminated polybutadiene (HTPB) and composite solid propellants (CSPs) using thermogravimetric analysis (TG), simultaneous thermogravimerty and differential scanning calorimetry (TG–DSC) and ignition delay measurements. Kinetics of thermal decomposition of AP + CdO has also been investigated using model free (isoconversional) and model-fitting approaches which have been applied to data for isothermal TG decomposition. All these studies show enhancement in the rate of decomposition of AP, HTPB and CSPs but no effect on HMX. The burning rate of CSPs has also been found to be increased with CdO nanocrystals.

Particulate matter in the exhaust of a boron- loaded solid propellant

2 Sturm, E. J. and Reichenbach, R. E., Aluminized Composite Solid-Propellant Burning Rates in Acceleration Fields, AIAA Journal, Vol. 7, No. 11, Nov. 1969, pp. 2087-2093. 3 Manda, L. J., Compilation of Rocket Spin Data, Vol. II: Literature Survey, Rept. 3001-2, CR-66641, 1968, NASA. 4 Anderson, J. B. and Reichenbach, R. E., '76-Inch Diameter Centrifuge Facility, TN 66T-4, Sept. 1966, Dept. of Aeronautics, Naval Postgraduate School, Monterey, Calif. 5 Sturm, E. J., A Study of the Burning Rates of Composite Solid Propellants in Acceleration Fields, Ph.D. thesis, AD832206, March 1968, Naval Postgraduate School, Monterey, Calif. 6 Green, L., Jr., Burning of Some Composite Solid Propellants, Jet Propulsion, Vol. 24, No. 1, Jan-Feb. 1954 DD 9-15. ' 7 Wimpress, R. N., Internal Ballistics of Solid Fuel Rockets, 1st ed., McGraw-Hill, New York, 1950. 8 Lawrence, W. J. and Deverall, L. L, The Erosive Burning Behavior of Selected Composite Propellants, Proceedings from the 4th ICRPG Combustion Conference, Stanford Research Inst., Menlo Park, Calif., Oct. 1967, pp. 459-466. 9 Crump, J., Aluminum Combustion in Composite Propellants, Proceedings of the Second ICRPG Combustion Conference, Aerospace Corp., El Segundo, Calif., 1965.

Errata: GLInitial Temperature and Pressure Effects on Composite Solid Propellant Burning Rates: Comparisons with Theory"

Pressure vs burning rate data are presented for an ammonium perchlorate composite solid propellant at four levels of initial temperature. For each level of initial temperature the data are fitted by least squares to the equation P/r = a + bPN. Three values of N are considered at each temperature level, N — 1, N = f and N = value for best fit to the data. These fits are then used to evaluate the relative merits of two burning rate laws, N = 1.00 corresponding to a law that includes the axisymmetric jet diffusion flame theory and N = f corresponding to the Summerfield granular diffusion flame theory. The relative variation of the parameters a and b with temperature is compared with the expectation of the Summerfield theory. It is concluded that although N = f gives a superior fit to N = 1.00, no law of the type P/r = a + bPN fits the data without systematic error and that the variation of best fit N with initial temperature casts doubt upon the physical model underlying both burning rate laws. The burning rate law suggested by Fenn, P/r = a + brPN also is tested. Its best fit is superior to that for N = 1 in the previous equation but it is inferior to the fit of that law for N = or N taken as the best fit value.

Initial temperature and pressure effects on composite solid-propellant burning rates - Comparisons with theory

Initial temperature and pressure effects on composite solid-propellant burning rates - Comparisons with theory

Aluminized composite solid-propellant burning rates in acceleration fields

The average burning rates of a parametric series of propellants were determined in acceleration fields up to 1000 g using a combustion bomb mounted on a centrifuge. The propellant strands were burned at 500, 1000, and 1500 psia with the acceleration field directed normal and into the burning surface. Acceleration caused a time-dependent increase of as much as 100% in the burning rate of relatively slow-burning aluminized propellants. The relative amount of burning-rate increase for the various propellants was strongly dependent on the amount of aluminum retained on the propellant surface during burning. The burning rates of two very fast-burning propellants were found to be essentially accelerationindependent. OLID-PROPELLANT rocket motors are currently being used in applications which subject the metallized propellant grains to acceleration fields. The propellant burning rates increase appreciably when the acceleration field is imposed normal and into the burning surface.1'2 Postfire inspections of motors containing metallized propellants have revealed the presence of metal and/or metal oxide residue in the motor cases. The propellant burning-rate increase and the retention of residue appear to be interrelated. The review and abstracting of the literature on the effects of acceleration on solid-propell ant performance are presented in Refs. 3 and 4. Although progress has been made toward an understanding of some aspects of burning-rate augmentation in acceleration fields, it was believed that additional experimental studies with well-controlled propellant parameters would yield valuable insight. A parametric series of aluminized propellants was formulated to establish the importance of some of the propellant parameters that could be controlled to minimize the effects of acceleration. The objectives of this investigation were twofold. The first objective was to obtain the quantitative effect of acceleration on the burning rate of the propellants as a function of propellant composition, acceleration level, and time. The second objective was to obtain quantitative information on the amount of aluminum and/or aluminum oxide residue retained in the inhibitor case as a function of propellant -composition, acceleration level, pressure level, and propellant burning rate.