提高复合固体推进剂燃速催化剂催化效率的途径

本文从燃速催化剂的浓度,催化界面,催化剂间的协同效应,以及对现有燃速催化剂进行改性等几个方面综合阐述了提高过氯酸铵复合固体推进剂燃速催化剂催化效率的途径,并用Summerfield燃烧理论作了说明。一、引言固体推进剂的燃烧速度是表征固体推进剂燃烧特征的一个重要参数。在实际应用中,随着发动机的用途不同,对固体推进剂的燃速高低要求也不一致。例如,助推器要求高燃速的     

纳米金属氧化物催化剂在固体推进剂中的应用进展

综述纳米金属氧化物催化剂在固体推进剂中的应用现状,包括纳米过渡金属氧化物催化剂、纳米稀土金属氧化物催化剂和纳米复合金属氧化物催化剂,总结了目前应用中存在的问题。认为固体推进剂用纳米金属氧化物作催化剂,可获得优于非纳米催化剂的燃烧性能。     

ADN及其固体推进剂燃烧特性的研究进展

系统介绍了二硝酰胺铵(ADN)燃烧的最新研究动态,综述了国内外近年来报道的ADN燃烧时发生的物理化学变化、ADN燃烧机理、催化剂/ADN混合物燃烧性能以及ADN基固体推进剂燃烧特性的最新研究进展。首先指出了ADN的燃烧主要受凝聚相反应控制,ADN燃烧波结构包括固相层、泡沫层(包括固-气和液-气)和气相层;其次,总结了ADN基固体推进剂燃烧特性的研究现状,对现有研究中存在的局限性进行了分析;最后,指出继续开发适用于ADN基固体推进剂的新型燃烧催化剂是今后研究的重点方向之一。另外,随着非异氰酸酯固化体系在ADN基固体推进剂中的应用,需进一步加深ADN基固体推进剂燃烧性能的研究,尤其是三唑环的引入对ADN热分解及推进剂中其他组分热分解的影响。     

固体推进剂含能燃烧催化剂研究现状与发展趋势

以含能基团为区分，综述了固体推进剂含能燃烧催化剂近年来的研究现状，总结了唑类、吖嗪类、二茂铁类、蒽醌类、石墨烯类及硝基类含能燃烧催化剂对固体推进剂及其主要组分的催化燃烧作用及催化机制。指出唑类和吖嗪类部分化合物对固体推进剂催化效果优异；二茂铁及衍生物含能化兼具提升能量和改善迁移；蒽醌类等新型含能催化剂也各有优势；含氮量越高，对催化剂体系能力贡献越大，可通过在氮杂环上引入硝基等含能基团以提高氮含量并改善催化剂的性能。指出今后含能燃烧催化剂的研究重点为：进一步开展多功能、多金属含能燃烧催化剂的设计及机理探索；同时加强含能燃烧催化剂对其他含能材料热分解的催化作用及在固体推进剂中的应用研究。附参数文献89篇。     

钙钛矿型复合氧化物催化剂应用研究进展

概述了钙钛矿型复合氧化物催化剂的结构特征,阐述了在光催化降解、汽车尾气净化、烟气催化脱硫、固体氧化物燃料电池以及固体推进剂催化燃烧等领域的应用研究进展,并分析了该类催化剂在各应用领域存在的技术难题以及发展前景.     

碳物质在固体推进剂中的功能及其作用机理

综述了碳黑（CB）、富勒烯烟炱（FS）、C60（Buckmister Fuller）、碳纤维（CF）及碳纳米管（CNTs）在固体推进剂催化燃烧中的作用、作用规律及作用机理。在双基系推进剂中加入碳黑和C60可富集催化剂,阻滞催化剂凝聚,使双基推进剂产生平台或麦撒效应,推进剂压力指数降低,低压下的燃速大幅度提高。碳纤维改善了推进剂燃烧表面的导热,增加了推进剂基体强度,可提高其燃速,预防复合推进剂的破裂。推进剂中的碳纤维、碳纳米管能加速含能材料的分解,提高推进剂的燃速。展望了固体推进剂中碳物质的发展方向。     

丁羟四组元复合推进剂燃烧稳定性机理研究综述

针对丁羟四组元复合推进剂的燃烧稳定性问题,从复合推进剂的微观燃烧角度出发,简述了复合推进剂易产生燃烧不稳定问题的主要机理,整理与总结了丁羟四组元复合推进剂中常见的4种组分:高氯酸铵(AP)、端羟基聚丁二烯(HTPB)、铝粉(Al)和高能硝胺组分黑索今(RDX)与奥克托今(HMX)的燃烧过程与火焰结构对固体推进剂燃烧稳定性的影响。通过探究各组分的燃烧特性与机理,有助于建立固体推进剂整体的燃烧模型,从而能在本质上解释复合推进剂不稳定燃烧产生的原因,并针对不稳定燃烧现象提出有效的抑制手段,对丁羟四组元复合推进剂今后的研究方向进行了展望。附参考文献72篇。     

高氯酸铵复合物研究概况

对近年来高氯酸铵(AP)与推进剂燃烧剂、燃烧催化剂、高导热材料碳纳米管(CNTs)组成的复合物的热分解性能进行了总结,介绍了燃烧剂、催化剂和CNTs在含AP推进剂中的应用效果。结合当前含AP推进剂研究现状,认为AP复合处理是改善推进剂燃烧性能、能量性能和工艺性能的新型方法和有效途径,AP复合物具有良好的工程应用前景。     

2,4-DNI铅盐的合成及性能

为解决惰性催化剂加入到固体推进剂中引起能量降低的问题,以咪唑为原料经两步硝化、热重排和复分解反应合成了一种新型含能燃烧催化剂2,4-DNI铅盐（PDNI）。测试了其机械感度、相容性等性能,并与PNTO进行了比较。结果表明,PNTO和PDNI与NC／NG体系均具有较好的化学相容性,比PNTO具有更低的机械感度和更好的热稳定性。将其作为含能燃烧催化剂应用于固体推进剂中,考察其对燃烧性能的影响,结果表明,PDNI在螺压改性双基推进剂配方中的燃烧催化作用与2,4-二羟基苯甲酸铅相当。     

提高复合固体推进剂燃速催化剂催化效率的途径

本文从燃速催化剂的浓度,催化界面,催化剂间的协同效应,以及对现有燃速催化剂进行改性等几个方面综合阐述了提高过氨酸铵复合固体推进剂燃速催化剂催化效率的途径,并用Summerfield燃烧理论作了说明。     

B-GAP对复合固体推进剂能量性能影响理论研究

提高复合固体推进剂的能量性能的方法之一,是将普通的HTPB黏合剂替换成为含能黏合剂B-GAP.利用最小自由能法,对含能黏合剂B-GAP对复合固体推进剂的能量性能影响进行了理论研究,并计算出应用B-GAP的推进剂的燃烧室平衡温度、喷管出口温度、比冲等能量性能参数,将这些性能参数与丁羟推进剂进行比较,发现均有一定程度的提高...     

Experimental study of the acoustic admittance of the burning surface of composite solid propellants

A method for measuring the acoustic admittance of the burning surface of solid propellants using a two-dimensional combustion chamber (T-burner) is considered. The paper presents the results of an experimental study of the effect of the pressure and frequency of acoustic oscillations in the combustion chamber and the effects of the composition, mass content, and aluminum powder particle size on the acoustic admittance of the burning surface of composite solid propellants.     

Friction sensitivity mechanism of Ammonium Perchlorate Composite Propellants

Friction sensitivity of ammonium perchlorate (AP) composite propellants has been studied experimentally by means of thermal analysis and micro-thermocouple techniques. Several types of catalysts were mixed with AP in order to examine the effect of the reactivity on the sensitivity. The results of friction sensitivity test show that the samples are sensitized when the concentration of catalysis which are used for high burning rate propellants is increased. Metal contents within the catalysts tend to give some effects on the friction sensitivity. Based on the results of the temperature profile measurements in combustion waves, it is found that the friction sensitivity is correlated with the burning surface temperature of the propellants. The catalysts which accclerate the AP decomposition are responsible for the friction sensitivity but not for the fallhammer sensitivity.     

复合催化剂对Al/HMX/CMDB推进剂安定性的影响

含有复合催化剂的Al/HMX/CMDB推进剂样品,在放置3~4周后,爆热、燃速下降,压强指数升高。为找到具体原因,对推进剂试样进行了燃烧性能、真空安定性及DSC热分解实验,并对实验结果进行了系统分析。结果表明:复合催化剂中超细的SnO2具有较强的催化活性,催化推进剂在常温下进行热分解,最终导致推进剂安定性、爆热、燃速下降,压强指数升高。推进剂性能的恶化,严重影响其正常使用。     

Burning Rate Evaluation of Composite Solid Propellants. A simplified approach

One of the principal parameters associated with a solid propellant is its linear burning rate. Many attempts have been made in the past to determine theoretically the burning rates of solid propellants by the use of appropriate combustion models. The object of the present paper is to propose a simplified theory of burning rate suitable for composite solid propellants. While the paper follows basically the scheme suggested for this purpose by Beckstead, Derr and Price using multiple flamelets, certain simplifying assumptions have been introduced with a view to make the model easier to operate. An attempt is also made in the paper to extend it to the case of aluminized solid propellants as well on the basis of a specific hypothesis regarding the role of aluminium. The relevant transcendental equations of combustion were solved on a digital computer. The burning rates and related characteristics were evaluated by this technique for two specific ammonium perchlorate-based solid propellants, one aluminized and the other non-aluminized, and the results obtained agree reasonably with the reported experimental trends.     

Influence of an Electric Field on the Burning Behavior of Solid Fuels and Propellants

An experimental study on the effects of an applied external electric field on the combustion behavior of solid fuels and solid propellants has been conducted. In an opposed flow burning configuration, application of an electric field was shown to extinguish a paraffin fuel and gaseous oxygen flame over a broad range of operating conditions. When subjected to the electric field, burning paraffin fuel strands were found to extinguish at various axial locations relative to the exit of the oxidizer gas jet. Extinguishment location was found to be a function of field strength as well as electrode surface area, while changes in polarity did not significantly alter the results. In addition, the combustion behaviors of two composite solid rocket propellants were studied while subjected to an external electric field. Both propellants were based on HTPB/AP combinations, with one propellant containing aluminum and the other being non‐aluminized. Application of an electric field to the composite solid rocket propellant strands demonstrated decreases in propellant burning rate under all operating conditions for both propellants including changes in polarity. The flame structure of the aluminized propellant was examined closely as the luminosity, flame length, and flame width varied significantly with field strength and burning location of the strand relative to the electrodes.     

Energetic Solid Fuels for Ducted Rockets (II)

The combustion characteristics of variable-flow ducted rockets were evaluated in order to obtain optimum design parameters of the gas generators. The energetic solid fuels used for the gas generators were glycidyl azide polymer (GAP) with burning rate catalysts. The burning rate of GAP based energetic fuels was much higher than that of composite and double-base based fuel-rich propellants. The pressure exponent of the burning rate was high enough to obtain a wide range of variable-flow rat. Two types of combustion test were conducted: a semi-free jet and a direct connect flow. The pressure-time response in the primary combustor obtained by the use of a throttable nozzle was evaluated.