China 
Africa 
Explore chapters and articles related to this topic
Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
Hypergolic propellant combination used in a rocket engine is one whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Although commonly used, hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness.
Significance and Administration of Nanotechnology in the Armed Forces and Defense Sector
Published in Cherry Bhargava, Amit Sachdeva, Pardeep Kumar Sharma, Smart Nanotechnology with Applications, 2020
Ali Asgher Ali Hasan, Roshan Rajesh Bhatkar, Sarath Raj Nadarajan Assari Syamala
Solid propellants are energy rich particulate compounds that, by their chemical virtues, exhibit solid-state crystalline structure. Gunpowder is commonly used as a propellant in military applications in ballistic projectile weapon. Another example of high-energy substance is an explosive. It is identical to a propellant, but differs only when the rate of combustion factor is considered. This is to say that the rate of combustion of propellants is slightly lower than that of high impact explosives. Furthermore, propellants burn gradually and in a controlled manner, whereas explosives’ combustion process is spontaneous and mostly uncontrolled.
Chemical Rocket Propellants
Published in D.P. Mishra, Fundamentals of Rocket Propulsion, 2017
Any solid propellant usually consists of fuel, oxidizer, and additives. Fuel and oxidizer are principal ingredients. Additives are used in very low percentage to enhance the burning rate, control fabrication process, minimize temperature sensitivity, to ensure chemical/physical stability during storage, to increase mechanical properties, and so on. Generally, solid propellants are designed for specific applications, namely, sounding rocket, missile, launch vehicle, gas generator, and so on. The desirable properties of solid propellants are enumerated as follows [2,5]:Solid propellant must have higher heating value to have higher combustion temperature, leading to high characteristic velocity C*.Propellant combustion products should have low molecular weight to have high exhaust velocity Ve, leading to high specific impulse Isp.It should have a high density such that large amount of chemical energy can be stored in the smallest volume and thus can have a compact design.Easy to ignite even under low pressure condition. But it must not ignite due to shock or pressure pulses.Its constituents should be easy to handle.Constituents of propellants must be locally available and cost-effective.Processing of propellant should be simple and reproducible in nature.Properties of propellant grain must not be physically and chemically unstable during storage and transport.Propellant grain must be inexpensive to manufacture and easy to handle during operation.Solid propellant grain must not react with atmospheric air/moisture.Propellant grain must have high mechanical strength.It must be smoke-free and nontoxic in nature.It must be less prone to explosion hazard.As discussed, solid propellants fall mainly into two categories: (1) homogeneous and (2) heterogeneous propellants, depending upon the physical entities of fuel and oxidizer in the propellant. Various types of homogeneous and heterogeneous solid propellants are discussed in the following.
Explosion Hazard of AP/HTPB in Fire Condition
Published in Combustion Science and Technology, 2023
Linghui Zeng, Huimin Liang, Zhongqi Wang, Qi Zhang
In recent decades, solid propellant has been widely used in aerospace (Hu et al. 2014; Yan et al. 2020) and military fields (Isik and Goktas 2017) because of its high specific impulse, high energy density, low cost and good aging properties. The mixture of ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) is a common propellant in solid engines, and its combustion process is stable (Xue, Yu, Ye 2018). AP can self-deflagrate under a variety of conditions, providing flame temperatures over 1400 K (Dennis and Bojko 2019). HTPB combined with AP crystals in a solid matrix provides the required mechanical properties and reduces combustion instability (Ye, Yu, Cao 2015). However, in the process of production, use, transportation and storage of propellant, there is a high risk of explosion if the propellant is stimulated by external heat. With the occurrence of many accidents of propellant detonating due to the fire in warehouses and aircrafts (MIL-STD-2105D, 2011), the thermal safety of energetic materials has been paid more attention.
Critical Condition of AP/HTPB Explosion Induced in Near Flame Area of Fire
Published in Combustion Science and Technology, 2022
Jianbo Yu, Jianping Li, Qi Zhang
With the rapid development of aerospace and military fields, the research of rocket propellant which is known as the “heart” of aircraft and missile has a vital impact on their future development (Liang, Zhang, and Zheng 2003). At present, rocket propellants are divided into solid, liquid and solid-liquid mixture. Solid propellant has become the mainstream power source of small rockets and most military missiles because of its simple structure, low economic cost and high stability (Ding et al. 2022). The composite propellant with hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (AP) as raw materials is the main propellant in the military field (Wu et al. 2019). However, with the improvement of propellant in energy performance and loading capacity, its safety performance should also receive higher attention (Dennis and Bojko 2019; Luo and Liu 2007). In recent years, fire accidents occur frequently (Li and Fan 2010), and the high combustion and explosion hazard of rocket propellant make the storage environment more strict (Ye and Yu 2018).
Early Liquid and Gas Phase Hypergolic Reactions between Monomethylhydrazine and Nitrogen Tetroxide or Red Fuming Nitric Acid
Published in Combustion Science and Technology, 2019
Ariel T. Black, Michael P. Drolet, Timothée L. Pourpoint
Within the realm of rocket propellants, hypergolic propellants are fuel and oxidizer combinations that ignite spontaneously shortly after contact with one another, eliminating the need for an external ignition source. Capable of performing multiple thrust maneuvers and engine restarts, hypergolic propellant engines are extensively used in propulsion applications involving orbital maneuvering and attitude control. Unfortunately, the most commonly used hypergols are acutely toxic, carcinogenic, and difficult to handle, prompting investigations into less toxic, “green” hypergolic propellant alternatives (Pourpoint, 2007). While progress continues, no propellant combinations have yet been broadly adopted that result in comparable performance characteristics to traditional combinations comprising nitrogen tetroxide-based oxidizers and hydrazine-derived fuels.