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本文评述了固体发动机喷管的设計。碳/碳材料引起的第一个突破是:使沿喷管内型面与燃气接触的耐烧蚀层具备了结构承载能力,使喷管成为承热结构,只是与燃烧室连接的部件需要绝热。很遗憾,如今用碳酚醛或硅酚醛材料制成的绝热层,因低溫下易炭化并逸出气体,所以它们的机械性能既低劣又不可預测。因此,喷管与燃烧室绝热连接处通常采用复杂的设計,它包括绝热的和金属的结构零件。目前出现一些新的、具有热稳定基体的绝热复合材料,由于这些材料在很大温度范围内具有结构承载能力,这将是喷管设計的第二个突破。本文评述了用陶瓷或碳纤维与基体制成的新的不炭化绝热材料,介绍了用这些材料设計新喷管的几个例子。它的优点是:设計新颖、简单,装配时间少,成本低以及分析預测性较好。
This article reviews the design of solid engine nozzles. The first breakthrough caused by the carbon / carbon material is that the ablatable layer that comes into contact with the gas along the inner profile of the nozzle has structural load carrying capacity, making the nozzle a heat-bearing structure, except that the components connected to the combustion chamber require thermal insulation. Unfortunately, thermal insulation made of carbon phenolic or silicone phenolic nowadays is both poor and unpredictable due to its susceptibility to carbonization and gas evolution at low temperatures. Therefore, the nozzle and the combustion chamber adiabatic connection is usually used in complex design, which includes insulation and metal structural parts. There are a number of new thermally insulated composites with thermally stable substrates that will be the second breakthrough in nozzle design due to the structural load carrying capacity of these materials over a wide temperature range. This article reviews new non-carbonized insulation materials made of ceramic or carbon fiber and matrix, and presents several examples of designing new nozzles with these materials. Its advantages are: new design, simple, less assembly time, low cost and better predictive analysis.