Chemical propulsion systems

Since 1950, plastics have been development for uses in very high temperature environments. By 1954, it was demonstrated that plastic materials were suitable for thermally protecting structures during intense propulsion heating. This discovery, at that time, became one of the greatest achievements of modern times, because it essentially initially eliminated the thermal barrier to hypersonic atmospheric flight as well as many of the internal heating problems associated with chemical propulsion systems. 

Only chemical propulsion will be further discussed, and in particular, that associated with liquid, solid, and hybrid motors and engines. These motors and engines are uniquely different from other chemical propulsion systems in that they carry on board the necessary propellants, as contrasted to jet engines that rely on atmospheric oxygen for combustion of the fuel. 

Although several different system configurations have been simulated, the focus of this paper will be on the unsteady, compressible, multiphase flow in an axisymmetric ramjet combustor. After a brief discussion of the details of the geometry and the numerical model in the next section, a series of numerical simulations in which the physical complexity of the problem solved has been systematically increased are presented. For each case, the significance of the results for the combustion of high-energy fuels is elucidated. Finally, the overall accomplishments and the potential impact of the research for the simulation of other advanced chemical propulsion systems are discussed. 

Pentaerythrital Tetranitrate (PETN) white, crystalline compound used as a detonating agent in blasting caps and detonating fuse CHEMICAL PROPULSION SYSTEMS PROPULSION SYSTEMS AND GAS GENERATORS Complete solid-fueled rocket motors and gas... 

Rocket propulsion moves a vehicle by ejecting mass out of the backside of the vehicle. Since there is no atmosphere in space, all of the reaction (i.e. propellant) mass must be carried on board and is usually released as a heated gas (i.e. the exhaust) expanding through a nozzle. All launches from earth into space have used chemical propulsion systems (i.e. reactions between a fuel and an oxidizer). The performance of a rocket vehicle is represented by the so-called first rocket equation ... 

A. B. Amster, et al. A Survey and Evaluation of High Energy Liquid Chemical Propulsion Systems , Final Report on Contract NASr-38, Stanford Research Institute (Nov. 1962). 

Plastics with their wide range of properties and characteristics have found numerous uses in chemical propulsion systems. The particular plastic employed in these applications is based on the inherent properties of the plastic or the ability to combine it with another component material to obtain a balance of properties uncommon to either component. 

Liquid propellants can be categorized by their type of storage (cryogenic propellants vs. storable propellants) or by their function in the chemical propulsion system (oxidizers, fuels, or monopropellants). The functional categorization is used here for discussion of the liquid propellants. In addition, liquid propellants, either oxidizer or fuel, can be gelled as a neat material or as a heterogeneous gel mixture containing suspended solid material such as aluminum powder. 

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