FUEL
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2023
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IF 7.4
Xinjian Zhou,Ruixuan Xu,Hongqi Nie,Qilong Yan,Jun Liu,Yunlan Sun
Burning rate modulation is a crucial but challenging technology for designing solid propellants. The core–shell structured Al@AP and Al@AP/CuO were prepared and their thermal reaction properties were investigated at different pressures. The precise catalytic mechanism of doped CuO in oxidizer and the key reason for its burning rate modulating effect on solid propellants were elucidated by combining DFT calculations. The *NH 4 ClO 4 on the CuO (1 1 1) surface is more likely to undergo a dehydrogenation reaction first. The large difference in activation energy between *NH 4 ClO 4 →*NH 3 +*ClO 4 +*H and *NH 4 ClO 4 → NH 3 + HClO 4 explains the reasons that CuO can reduce the ignition delay of the Al@AP. CuO promotes the decomposition of the AP@Al at the low- and high-temperature decomposition (LTD and HTD) stage. For the Al@AP-CuO, the temperature of the high-temperature decomposition peak (THTD) does not shift to the lower temperature range with increasing pressure. These results are responsible for a reduction of pressure exponent in the presence of minor CuO as reported in the literature. CuO can facilitate the transformation process *NH 3 →*NH 2 on the CuO (1 1 1) surface at low-temperature and low-pressure conditions. However, at high-temperature and high-pressure conditions, it can inhibit the reaction *NH 2 →*NH→*N, so the burning rate of solid propellants can be controlled.
研究领域:
材料科学
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化学工程
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Lu Liu,Lipeng Sang,Dongliang Gou,Zhan Wen,Gangchui Zhang,Peijin Liu,Guoqiang He,Wen Ao
New micro-unit composite fuels Al@AP with different mass ratios of Al and AP are designed, prepared, and added to solid propellants in place of the original aluminum powder . Through Thermogravimetric Analysis- Differential scanning calorimetry- Mass Spectrometry (TG-DSC-MS), laser ignition experiment, thermocouple temperature measurement, burning rate test, and combustion diagnostic, we study how Al@AP affects the ignition, combustion, and agglomeration properties of solid propellants. The results indicate that the increase of Al content of Al@AP can promote the advance of thermal decomposition of AP. As the AP content increases in Al@AP, the ignition delay time of Al@AP decreases by three times, and the mass burning rate increases by almost five times. At the same time, Al@AP significantly improves the burning rate and temperature gradient . When compare to the baseline propellant, Al@AP-containing propellants present a maximum increase in burning rate of 33% at low pressures and 19% at high pressures. In terms of agglomeration reduction, the number of large-size agglomerates in the CCPs of propellants containing Al@AP is reduced, the average particle size decreases by 78%, and the combustion efficiency increases to 99.34%. A mechanism is proposed to explain how the micro-unit composite fuel Al@AP alters propellant combustion and agglomeration. In summary, Al@AP provides excellent control over ignition, combustion, and agglomeration characteristics. This study provides guidance on the application and development of new aluminum-based composite fuels used in solid propellants.
研究领域:
材料科学
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燃烧学
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推进技术
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Ruixuan Xu,Xin Li,Zhihua Xue,Danfeng Yang,Suhang Chen,Kangzhen Xu,Qi-Long Yan,Hongqi Nie
In this work, the combustion enhancement and agglomeration inhibition of HTPB-based composite propellants have been achieved by incorporation of Al@AP composites containing a nitrogen-rich compound 4,4′,6,6′-tetra(hydrazino)hydrazo-1,3,5-triazine (THHT) as a burning rate modifier. The thermal reactivity and decomposition behavior of Al@AP/THHT composites were studied using DSC/TGA/FT-IR techniques. These composites showed a greater heat release with lower decomposition peak temperature. The propellant formulations could be well tuned by adjusting the mutual distance between Al/AP and THHT crystals. The results suggest that the inclusion of Al@AP/THHT in solid propellants would lead to enhanced energy release, with the value of explosion heat increased from 5632.0 J g -1 to 5971 J g -1 (+6.0 %), the ignition delay time decreased from 105 ms to 79 ms (-24.8 %) and the flame radiation intensity maximum raised from 2199 to 1988 (+10.6 %). The modified propellants are featured with a chemical reaction-dependent flame propagation rate at lower pressure range (1∼10 MPa) and a pressure-controlled process over 10 MPa. The burning rate of propellant at 1 MPa can be increased from 6.1 mm s -1 to 7.0 mm s -1 (+14.8 %) by the inclusion of Al@AP/THHT. The pressure exponent of modified propellants was reduced from 0.48 to 0.33 in pressure range 1∼15 MPa, which is mainly attributed to the activation of Al@AP at lower pressure. Furthermore, the inhibition of Al agglomeration was found once it was coated with AP. The characterizations on condensed combustion products (CCPs) demonstrated an enhancement in combustion efficiency due to an increased content of Al 2 O 3 , accompanied with a remarkable reduction of mean size from 14.0 μm to 1.3 μm (-90.7 %) and a rise in the proportion of nano-/micron-sized particles. The overall effects of Al@AP interfacial control and precise catalysis of THHT on the energy release and combustion of propellants were identified and the primitive combustion mechanisms are proposed.
研究领域:
推进剂化学
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燃烧科学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Lyu Jie-Yao,Yang Su-Lan,Wu Shixi,Tang Gen,Yang Wenming,Yan Qi-Long
Burning rate modulation is a critical but challenging technology for solid propellants’ design. Great efforts have been made to synthesize and utilize catalysts to modify the pressure exponent ( n ), but poor catalytic efficiency and lower energy level of conventional catalysts limit their further applications. In this research, interfacial control of Al@AP together with precise catalysis of CuO is represented for the purpose of pressure exponent reduction and combustion performance improvement. The core-shell structured Al@AP and Al@AP/CuO composites were prepared and applied into HTPB/Al/AP composite propellants. These prepared propellants have the same formula but different micro-structures of ingredients, leading to varied combustion performance, in terms of the burning rates, combustion wave structures, flame spectra, agglomeration processes of Al particles and condensed combustion products . The investigation results show that by using interfacial control of Al@AP and precise catalysis of CuO, the n of involved propellants over 1–4 MPa can be greatly decreased from 0.42 to 0.21 and the agglomeration of Al could be effectively inhibited. In addition, propellants based on Al@AP and Al@AP/CuO interfacial controls of this research are summarized and compared together with those based on Al@RDX published recently, to present overall characteristics of interfacial control techniques, which could lead to the development of new smart controllable propellants.
研究领域:
材料科学
·
推进技术
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Jie-Yao Lyu,Geng Xu,Haorui Zhang,Wenming Yang,Qi-Long Yan
Conventional solid propellants suffer from undesirable combustion performance due to the poor mass and heat transfer between metal fuels and oxidizers, as well as a lack of catalytic active sites between the catalyst and catalyzed objects. Embedding metal fuels and catalysts within the oxidizer has shown promise in improving the overall combustion performance of HTPB/AP/Al and HTPB/AP/RDX/Al composite solid propellants. However, the underlying mechanisms responsible for this enhancement remain to be further understood. In this study, we investigated the reactivities of core–shell Al@AP and Al@AP/CuO composites using thermal analysis and combustion diagnostic techniques. The results demonstrated that the decomposition of AP was promoted, as evidenced by a lower peak temperature (415.2–334.7 ℃), higher total heat release (116.4–720.8 J·g −1 ), a transition in the decomposition physical model from the random nucleation and 2D/3D growth of nuclei model to the auto-catalytic model, and increased generation of NO 2 . Furthermore, the Al@AP/CuO propellant pellet exhibited a more stable flame without agglomeration, and the condensed combustion products (CCPs) contained a lower amount of unreacted Al compared to that of conventional mixtures. These findings highlighted the potential of core–shell Al@AP and Al@AP/CuO composites as replacements for discrete ingredients of solid propellants, thereby offering improved performance for next-generation propulsion systems.
研究领域:
推进剂技术
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材料科学
·
燃烧动力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Xin Li,Ruixuan Xu,Hao Zhang,Heng Deng,Qi-Long Yan,Hongqi Nie
Aluminum (Al) can significantly improve the energy density and specific impulse (I sp ) of solid rocket propellants as the primary metal fuel, but its incomplete combustion results in an undesirable energy release performance. The strategy of fuel/oxidizer interfacial control has been proved to effectively enhance the reaction efficiency of Al-based composites and thus improving the combustion properties of solid propellants. Ammonium perchlorate (AP) is commonly used as a high-energy oxidizer in solid propellant, and its thermal decomposition behavior directly affects the combustion characteristics of propellants. The addition of combustion catalysts can decrease thermal decomposition temperature and increase thermal reactivity of AP. As an emerging catalytic material, MoO 3-x quantum dots (QDs) with oxygen vacancies possess a high specific surface and strong charge adsorption capacity, which renders it a great potential for catalyzing AP. In this study, MoO 3-x QDs were introduced as catalyst and compared with traditional nano-metal oxides (M x O y ), the spherical Al@AP/M x O y composites with polydopamine as interfacial layer were prepared by spray drying method. The particle morphology, thermal decomposition kinetics and ignition properties of Al@AP/M x O y were investigated. The phase composition, morphology and particle size distribution for the condensed combustion products of composites were further analyzed. The decreased particle size and less unreacted Al content in CCPs indicated the increase of combustion efficiency between Al and AP. In particular, Al@AP/MoO 3-x has the higher heat of reaction, lower thermal decomposition temperature and small CCPs particle size distribution, which collectively suggested that the MoO 3-x is capable to improve the thermal reactivity of Al@AP composites with a higher combustion efficiency.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xin Li,Yunlong Zhang,Ruixuan Xu,Qi-Long Yan,Hongqi Nie
The synergistic regulation of high energy output and low sensitivity has been a persistent research focus in solid propellant development. In this study, oxygen-deficient MoO3–x quantum dots (QDs)-modified Al@AP core–shell composites were fabricated via spray-drying, with a reference system containing fine AP (s-AP) serving as a control group. Systematic investigations were conducted on the interfacial modification effects and the incorporation of MoO3–x QDs on the energy release characteristics, ignition-combustion performance, and safety properties of HTPB-based composite propellants. The results indicate that SP4 with Al@AP/MoO3–x has significantly enhanced energy outputs compared with SP1 containing Al/AP, and the heat of reaction increased from 6270 to 6615 J·g–1 under identical loading densities. Meanwhile, the ignition delay time of SP4 was shortened from 25.76 to 16.38 ms, and the flame radiation intensity was increased from 1640.8 to 1944.2, indicating a significantly improved ignition property. Furthermore, the higher burning rate at low pressure and suppressed rate surges at high pressure of SP4 result in a reduced burning rate pressure exponent (from 0.57 to 0.39). Safety tests revealed lower impact sensitivity for Al@AP/MoO3–x versus Al/AP/s-AP systems based on the increased burning rate. Condensed combustion product (CCP) analyses demonstrated that the core–shell structure effectively mitigated Al agglomeration, evidenced by increased fine particles and decreased Al residues, indicating an enhanced combustion efficiency. MoO3–x QDs further optimized the CCP size distribution, reducing the dominant particle size from 44.7 to 22.3 μm.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）