固体火箭发动机的热安全性研究

采用带源项的热传导方程,对固体火箭发动机在外界热源作用下的加热过程进行了数值模拟,分析了固体发动机内推进剂在外界热源作用下的燃烧特点,并确定了发动机产生热危险性的临界温度和起始燃烧时间。研究结果表明,在热传导方程中加入化学反应源项,可以有效地模拟发动机在外界热源作用下的加热过程;推进剂产生热危险性的临界温度为520～525K;在外界火焰作用下,发动机内的推进剂将点火燃烧,随着外界火焰温度的上升,推进剂起始燃烧的延迟时间减少。     

智能弹药用新型电控固体推进剂的研究进展

针对当前固体火箭发动机无法重复启停、难以实现推力可控等需求,结合固体火箭和液体火箭的优点,国内外研究机构探究了一种具有重复点火与熄火、燃烧速度可调、输出能量可控的电控固体推进剂。系统介绍了新型电控固体推进剂领域的国内外研究现状,首先,总结了国内外各类电控固体推进剂(硝酸铵基、硝酸羟胺基、高氯酸锂基)的发展,以及在微推、炮弹点火器和固体发动机方面的应用情况;其次,概述了配方组分、电压、电流、外界环境温度和压强等因素对电控固体推进剂的燃速、点火延迟时间以及力学性能的影响;然后,分析了电控固体推进剂的启停机理,介绍了硝酸铵羟胺和高氯酸锂基电控固体推进剂的反应机理;最后,对电控固体推进剂的未来发展进行了展望,指出未来仍需重点研究的方向：加强电控固体推进剂制备工艺放大研究;设计新型电敏氧化剂,解决高压下无法可控燃烧的问题;开展大尺寸电控固体发动机试验研究;通过数值模拟进一步揭示电能与推进剂燃烧耦合效应。附参考文献62篇。     

GAP/B贫氧富燃洁净推进剂用于固体火箭冲压发动机的前景分析

简述了固体火箭冲压发动机的特点及其对推进剂的要求,以及国内外固体火箭发动机用贫氧富燃推进剂的研制现状。通过对贫氧富燃推进剂配方和组分选择的探讨和GAP/B富燃洁净推进剂用于冲压发动机的前景分析,认为GAP/B富燃洁净推进剂是开发新一代高超音速飞航式导弹用固体火箭冲压发动机的优良的候选推进剂。     

某型号导弹固体发动机贮存使用寿命研究

利用推进剂方坯加速老化试验对某型号导弹固体发动机进行了推进剂贮存寿命预估。通过对试验数据的分析,建立了固体推进剂老化速率的动力学方程,预估了固体推进剂的贮存寿命。结果表明,推进剂在25℃下贮存10 a后最大伸长率(εm)为31.57%,与起始εm比较,仅下降了27%,满足发动机安全使用要求。     

《低特征信号固体推进剂技术》新书简介

正由西安近代化学研究所燃烧与爆炸技术重点实验室原学术委员会主任李上文研究员等编著的《低特征信号固体推进剂技术》一书由国防工业出版社出版,该书为火炸药技术系列专著,共278页,内容系统深入,多项技术已应用于指导科研生产实践,对提高我国推进剂领域的科学技术水平具有重要意义。该书共分9章:第1章介绍发动机羽流及特征信号的基本概念,提出推进剂按特征信号进行分类的意     

固体推进剂的应用

固体推进剂以其结构简单、性能稳定、使用方便、易于大量生产而被广泛应用于火箭发动机中作为能源。固体推进剂及固体火箭发动机的应用场合很广泛,不同的使用场合对推进剂提出了不同的要求。本文就目前国内外固体推进剂的应用情况略加论述,并对固体推进剂的发展前景提出一些看法。     

长期贮存固体发动机中推进剂及其界面性能研究

将经长期贮存的某战术型号发动机作为研究对象,对该发动机使用的聚(PO/THF共聚醚)(/BDNPA/F)/AP/Al复合固体推进剂进行了研究,测试了长期贮存后发动机中的推进剂性能,检测了其装药界面。结果表明,该型号发动机存放20年以上,推进剂界面黏结保持良好,装药内部结构完整。该点火发动机存放28年,性能基本满足要求,工作正常。     

低温固体推进剂的研究进展

介绍了国外低温固体推进技术（CSP）的研究和发动机试验情况。重点介绍了国外H2O2基低温固体推进剂和ALICE（铝冰）推进剂的研究进展。详细分析了ALICE推进剂应用于固体火箭发动机的可行性,并对我国发展CSP推进剂提出了几点建议。     

影响固体火箭发动机初始压强峰的因素分析

针对某型号固体火箭发动机初始压强峰峰值超差的现象,分别对固体推进剂的能量特性、初始燃烧表面、发动机所用的点火具、测试系统以及发动机的装配过程等可能引起初始压强峰峰值超差的因素,进行了理论分析和实验验证。结果表明,发动机内筒涂层过厚,使得装配完的发动机的初始通气参量变大,同时发动机装配过程不合理,产生从推进剂药柱上刮下来的药屑,这些均导致初始压强峰超标。     

报废固体推进剂处理技术研究进展

火箭发动机退役更替和在生产过程中所产生的报废固体推进剂是一种具有特殊性质的危险品,必须妥善处理,各国对报废固体推进剂回收与再利用进行了多方面的研究。文中从报废固体推进剂的预处理技术、安全销毁技术、资源化处理技术及具有R3特性新型绿色固体推进剂发展等方面介绍了报废固体推进剂的处理技术研究进展。     

Short-Action Solid Rocket Motors with Double-Base Propellants

Due to various reasons double-base solid propellants have been replaced increasingly by composite propellants in the past years. However, the ALARM rocket motor of the Bayern-Chemie GmbH is one exception. Applications ideal for double-base propellants are short-action rocket motors with burning times ranging from some milliseconds up to approximately 200 ms. Various rocket motors of this type were developed at Dynamit Nobel GmbH for different kinds of application. Based on multiple-tube grains improved designs and manufacturing methods have been developed to enable cost-effective solutions even at low production rates. This includes also simplified test procedures to supervise the propellant fabrication.     

Evaluation of Mechanical Properties of Solid Propellants in Rocket Motors by Indentation Technique

It is essential to evaluate the mechanical properties of propellants in a solid propellant rocket motor (SPRM) for structural integrity and its performance evaluation before the flight test. Conventionally, uni‐axial tensile testing on an universal testing machine (UTM) is used to evaluate the mechanical properties of solid propellant carton which is cast along with SPRM. Propellants in rocket motors experience various types of loading during storage, transportation, and environmental conditions over the period of time before actual flight whereas the propellant carton doesn’t experience the same as it is stored in magazine. At present, the mechanical properties of propellant cast in a carton are considered to be the mechanical properties of propellant in a rocket motor, which is not truly representative. Therefore, a non‐destructive indentation technique has been used to establish a method for evaluating the mechanical properties of solid propellants in rocket motors based on hydroxyl terminated polybutadiene. The test results obtained using the penetrometer indentation technique was analyzed comprehensively and compared with UTM results. The mathematical correlations were also developed using least square method and established by conducting the penetrometer indentation test on similar propellant composition. Further, the developed correlation was used to evaluate the mechanical properties of propellant in flight SPRM by penetrometer indentation technique.     

Prediction of the Size of Aluminum-Oxide Particles in Exhaust Plumes of Solid Rocket Motors

The processes of coagulation and aerodynamic fragmentation of liquid particles of aluminum oxide in an accelerating gas flow in the Laval nozzle are analyzed. A formula obtained by an approximate analytical solution of equations of a two-phase flow is proposed to calculate the characteristic particle diameter at the nozzle exit. The limiting particle diameter in the nozzle throat calculated theoretically is close to the mean-mass diameter obtained by numerical simulation of polydisperse two-phase flows with particle coagulation and fragmentation. The formula proposed is in agreement with Hermsen's correlation dependences and is confirmed by numerous published data on measurement of the mean-mass diameter of aluminum-oxide particles in exhaust plumes of small-, medium-, and large-scale solid rocket motors. The formula contains physical parameters whose values are readily calculated and prescribed. The formula is tested by all the parameters that enter into it. Based on a comparison of theoretical calculations and numerous experimental data, the formula is recommended for prediction of the size of aluminum-oxide particles in exhaust plumes of various types of solid rocket motors. Key words: rocket motor, two-phase flow, aluminum oxide, fragmentation of drops.     

Comparative Study on Infrared Irradiance Emitted from Standard and Real Rocket Motor Plumes

The infrared irradiance signature from exhaust plume is essential for the design of solid rocket motors. To overcome the difficulty of conducting experiments using real rocket motors, experimental studies were carried out to compare standard rocket motors and real rocket motors of the same propellant. The static firing tests on standard and real rocket motors of NEPE and HTPB propellants were conducted. Despite different rocket motor size and methodology of spectro‐radiometric measurement, the spectral characteristics of the infrared irradiance signature for both rocket motors were quite similar. The standard and real rocket motors of HTPB propellant showed similar tendency of steady infrared irradiance emission throughout the combustion, whereas both rocket motors of NEPE propellant showed a rapid emission in the midstream of combustion. The total infrared irradiance of NEPE was about 55 % less than that of HTPB propellant for both standard and real rocket motor experiments. Additionally, the relative amounts of chemical products produced during propellant combustion came out to be similar for both rocket motors. The experimental results indicated that the spectral characteristics of infrared irradiance and combustion products were quite similar for different sized rocket motors of same propellant and that a correlation of infrared irradiance signature exists between small‐sized standard rocket motors and real rocket motors. Thus, the spectral characteristics of real rocket motors could be reasonably estimated from the results of standard rocket motors.     

Some Aspects on Safety and Environmental Impact of the German Green Gel Propulsion Technology

This article gives a short introduction into the technology of gelled propellant rocket motors and gas generators. A brief introduction outlines the specific features of the German green gelled propellant rocket motor technology and the family of monopropellants that cover a variety of requirements with respect to smoke, combustion temperature, and combustion pressure ranges. The discussion of the hazard potential comprises military insensitive munitions (IM) and civil classifications as well as a comparative assessment of the environmental and health impacts from manufacturing over use and finally to disposal. Summarizing the properties over all categories shows that gelled propellants provide a unique combination of good insensitivity and low environmental and health hazard potential compared to other liquid propellants, fuels, and oxidizers or solid rocket propellants.     

Coupled problem of modeling the internal ballistics of nozzleless solid rocket motors

A physicomathematical formulation of the coupled gas-dynamic and geometric problem of modeling intrachamber processes and calculating the internal ballistics of nozzleless solid rocket motors is given, and a method and algorithm for solving the problem are developed. The parameters in the forward section of the motor are calculated using averaged unsteady equations of internal ballistics, and the parameters of the grain channel and the exit cone are determined using one-dimensional gas-dynamic equations in a quasi-steady formulation. The software package is verified by calculating the internal ballistics of a motor which is utilized without nozzle cluster and simulates intrachamber processes in a nozzleless solid rocket motor during the full-duration firing. The design features, motor operating parameters, and the composition characteristics influencing the energetics of propellants in nozzleless solid rocket motors are calculated. It is shown that, depending on comparison conditions (identical expansion ratios and identical profiles of the nozzle and exit cone), the specific impulse of nozzleless solid rocket motors (the main energy parameter) is slightly smaller than or nearly comparable to that of conventional solid rocket motors.     

Radiation Emitted from Rocket Plumes

The signature of rocket plumes can be used for detection, identification and guidance of rockets. The objective was to investigate the signature of various types of solid rocket propellants by application of spectroscopic methods. The emission and transmission characteristics of plumes were studied experimentally, the results were analyzed based on molecular bands and continuum radiation. The model formulations include a nitramine propellant, a double-base propellant and a composite propellant. Applied were rapid-scanning filter wheel spectrometers for the wavelength region from 1.2 μm to 14 μm with a time resolution of 50 spectra/s and a wavelengths resolution of 1% of actual wavelength. The UV/VIS wavelengths region was recorded by an OMA system with wavelength resolution of 0.1 nm and 1 nm and time resolution of 10 spectra/s. Molecular bands of water and carbon dioxide dominate in the near infrared and infrared. Depending on composition, continuous radiation indicates particles in the rocket exhaust. A code was developed to calculate molecular bands and continuous radiation using temperature and species distributions found by thermodynamic estimation to obtain the radiance of the plume. Comparison with experimental data delivered plume temperatures.     

Smokeless GAP‐RDX Composite Rocket Propellants Containing Diaminodinitroethylene (FOX‐7)

Composite rocket propellants prepared from nitramine fillers (RDX or HMX), glycidyl azide polymer (GAP) binder and energetic plasticizers are potential substitutes for smokeless double‐base propellants in some rocket motors. In this work, we report GAP‐RDX propellants, wherein the nitramine filler has been partly or wholly replaced by 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7). These smokeless propellants, containing 60% energetic solids and 15% N‐butyl‐2‐nitratoethylnitramine (BuNENA) energetic plasticizer, exhibited markedly reduced shock sensitivity with increasing content of FOX‐7. Conversely, addition of FOX‐7 reduced the thermochemical performance of the propellants, and samples without nitramine underwent unsteady combustion at lower pressures (no burn rate catalyst was added). The mechanical characteristics were quite modest for all propellant samples, and binder‐filler interactions improved slightly with increasing content of FOX‐7. Overall, FOX‐7 remains an attractive, but less than ideal, substitute for nitramines in smokeless GAP propellants.     

Viscosity Prediction of Composite Solid Propellant Slurry

The viscosity of composite solid propellant slurry is an important parameter in charging technical performance of solid rocket motors. It is affected not only by the liquid phase ingredients of propellants, but also by the size, content, shape and surface properties of solid fillers in propellants. This paper will present a prediction formula of viscosity of composite solid propellant and will also give a method for calculating the maximum packing volume fraction of solid in the formula. One can predict the viscosity of propellant slurry with the formula if the composition of the propellant is known.     

Ultrasonic Investigation of Mechanical Properties of Double Base Rocket Propellants

For a series of double base rocket propellants and for poly- methylmethacrylate (PMMA) the longitudinal and transverse sound wave velocities are measured at a frequency of 0.351 MHz in t h e temperature range of −40°C to +60°C. The relations between these acoustic properties and mechanical properties are given and the principal independent elastic constants are calculated. With increasing temperature these constants of the propellants decrease gradually, which points to a softening of the material. This is important for the functioning of the propellant grains in the rocket motors.