Combustion mechanism of composite solid propellant sandwiches containing nano-aluminium

Gnanaprakash, K.; Chakravarthy, Satyanarayanan R.; Sarathi, R.

doi:10.1016/j.combustflame.2017.04.024

Cited by 41 publications

(9 citation statements)

References 30 publications

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“…The size measurement method of agglomerates [31] and agglomeration model [32][33][34][35] are also the research hotspot. At present, the most commonly used method is to use high-speed microscopic photography [4,32] to capture the agglomeration of aluminum in the combustion process or to judge the influence of different propellant compositions and environment on agglomerates by collecting combustion products [36].…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Combustion Characteristics and Agglomeration of Al/NEPE Propellants

Zhang

Feng³

et al. 2021

Propellants Explo Pyrotec

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In order to understand the ignition and combustion characteristics of NEPE propellants under different pressure conditions and the agglomeration behavior of aluminum particles on the burning surface, the Al/NEPE propellant was tested on a sealed high-pressure laser ignition platform. Laser ignition experiments show that both ignition delay time and combustion time are inversely proportional to ambient pressure. With the increase of pressure, the reduction of ignition delay time and self-sustaining combustion time is reduced. The impact of pressure on ignition and combustion is very complex. We then analyze the effect of pressure on ignition delay time using a theoretical mechanism. High-speed microscopic images display the agglomeration of aluminum particles in propellants mainly through the following three processes: accumulation, aggregation, and agglomeration. It is also found that many aluminum particles are agglomerated on the surface, the aluminum droplet agglomerates formed on the combustion surface are separated from the combustion surface, and the agglomerates rupture and flow out of the liquid alumina during the combustion process. The phenomenon of secondary agglomeration is also observed. The microstructure and elemental composition of combustion products of aluminum particles in NEPE propellant were obtained by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The detection results confirmed some agglomeration phenomena. At 3.0 MPa, the combustion of the propellant sample is sufficient, and the aluminum particles are smooth spherical alumina particles. At 1.0 MPa, the combustion of the propellant sample is insufficient, and the aluminum particles are rough. The particle size under different pressure was analyzed by a laser particle size analyzer. The results show that increasing the pressure can reduce the average agglomeration size of aluminum particles and improve combustion efficiency. The number of large particle aggregates is more at 3 MPa. From the perspective of overall particle size results, within the same diameter interval, the percentage of particle number does not increase or decrease significantly with the increase of pressure.

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Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Combustion Characteristics and Agglomeration of Al/NEPE Propellants

Zhang

Feng³

et al. 2021

Propellants Explo Pyrotec

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“…The effects of CL-20 and RDX on basic properties of CMDB propellants were investigated, the major findings could be summarized as follows: 1) The calculations on energetic properties for CL-20/RDX-CMDB propellants showed that energetic properties of propellant with CL-20 were superior to of propellant with RDX. 2) The data on burning rate revealed that with the increase of RDX/CL-20 mass fraction in the propellants, the burning rates at low pressure (2-8 MPa) remained almost the same but differ observably at high pressure (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). With the increase of CL-20 mass fraction in the propellants, the burning rates of propellants could be enhanced significantly, but the burning rates of propellants containing RDX decreased.…”

Section: Resultsmentioning

confidence: 97%

“…Joseph Kalman et al [17] investigated the effect of CL-20 particle size on the combustion of CL-20/HTPB propellants down to submicrometer sizes, the burning rate and combustion mechanism were discussed in detail. A large number of papers have been concerned with the combustion and energetic properties of HTPB and NEPE propellants [18][19][20][21][22][23][24]. However, there are very few publications on the effect of CL-20 particles on the combustion and energetic properties of composite modified double-base propellants (CMDB) [25][26][27], especially on its combustion residues properties.…”

Section: Introductionmentioning

confidence: 99%

Study on Comparative Performance of CL‐20/RDX‐based CMDB Propellants

Yang

Zheng

Zhang

2019

Propellants Explo Pyrotec

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The energy, combustion and combustion residues properties of composite modified double‐base (CMDB)propellants with CL‐20 were compared to those propellants with RDX. The energy characteristic of CL‐20/RDX‐CMDB propellants had also been calculated theoretically based on the principle of minimum free energy. The energy property of propellants with CL‐20 was found to be evidently enhanced in comparison to those propellants containing RDX. The findings on combustion properties revealed that the combustion properties of CL‐20‐CMDB propellants were contrary to the of RDX‐CMDB propellants. With the mass fraction of CL‐20 increasing in the propellants, the burning rates of propellants can be enhanced significantly, but the burning rates of propellants containing RDX decreased. Analysis of the combustion residues for CL‐20/RDX‐CMDB propellants revealed that the C, Cu and Pb elements aggregated on combustion surface, which may be useful for guiding the regulation of combustion performance of high‐performance CMDB propellants containing CL‐20.

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“…Gnanaprakash et al [38] also proved the earlier burning rate outcome through carrying out the experimental investigation on the combustion of AP/HTPB/Al sandwich propellants. Sandwiches comprise the HTPB matrix, mixed of ∼45 nm Al with the fine AP particles with the sizes of either 5 or 45 µm, fabricated over three various middle lamina thickness ranges: thin (100 to 170 µm), intermediate (200 to 280 µm), and finally thick (370 to 480 µm).…”

Section: Sandwich Combustionmentioning

confidence: 85%

Combustion Characteristics of Nanoaluminium-Based Composite Solid Propellants: An Overview

Jayaraman

Sivakumar

Zarrabi

et al. 2021

Journal of Chemistry

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The nanosized powders have gained attention to produce materials exhibiting novel properties and for developing advanced technologies as well. Nanosized materials exhibit substantially favourable qualities such as improved catalytic activity, augmentation in reactivity, and reduction in melting temperature. Several researchers have pointed out the influence of ultrafine aluminium (∼100 nm) and nanoaluminium (<100 nm) on burning rates of the composite solid propellants comprising AP as the oxidizer. The inclusion of ultrafine aluminium augments the burning rate of the composite propellants by means of aluminium particle’s ignition through the leading edge flames (LEFs) anchoring above the interfaces of coarse AP/binder and the binder/fine AP matrix flames as well. The sandwiches containing 15% of nanoaluminium solid loading in the binder lamina exhibit the burning rate increment of about 20–30%. It was noticed that the burning rate increment with nanoaluminium is around 1.6–2 times with respect to the propellant compositions without aluminium for various pressure ranges and also for different micron-sized aluminium particles in the composition. The addition of nano-Al in the composite propellants washes out the plateaus in burning rate trends that are perceived from non-Al and microaluminized propellants; however, the burning rates of nanoaluminized propellants demonstrate low-pressure exponents at the higher pressure level. The contribution of catalysts towards the burning rate in the nanoaluminized propellants is reduced and is apparent only with nanosized catalysts. The near-surface nanoaluminium ignition and diffusion-limited nano-Al particle combustion contribute heat to the propellant-regressing surface that dominates the burning rate. Quench-collected nanoaluminized propellant residues display notable agglomeration, although a minor percentage of the agglomerates are in the 1–3 µm range; however, these are within 5 µm in size. Percentage of elongation and initial modulus of the propellant are decreased when the coarse AP particles are replaced by aluminium in the propellant composition.

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Combustion mechanism of composite solid propellant sandwiches containing nano-aluminium

Cited by 41 publications

References 30 publications

Experimental Investigation on Combustion Characteristics and Agglomeration of Al/NEPE Propellants

Experimental Investigation on Combustion Characteristics and Agglomeration of Al/NEPE Propellants

Study on Comparative Performance of CL‐20/RDX‐based CMDB Propellants

Combustion Characteristics of Nanoaluminium-Based Composite Solid Propellants: An Overview

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