本帖最后由 猎鹰 于 2013-10-7 23:55 编辑

据说乙醇/甲醇比冲低于煤油就是因为里面具有羟基~~~~~~剩下就不需要我解释了。

貌似就是这一篇XXXXXXXXXXXXXXXXXXXXXXXX/t/60309

猎鹰 发表于 2013-10-7 23:51
据说乙醇/甲醇比冲低于煤油就是因为里面具有羟基~~~~~~剩下就不需要我解释了。

貌似就是这一篇http://bb ...

这篇好像没讲

c7h5n2o4 发表于 2013-10-10 21:19
这篇好像没讲

就在开头的一段啊~~~~~~~

During and immediately after World War II, alcohols (primarily ethyl alcohol, occasionally methyl alcohol) were the single most common fuel for large liquid-fueled rockets. Its high heat of vaporization kept regeneratively-cooled engines from melting, especially considering that alcohols would typically contain several percent water.

由于内部含水


However, it was recognized that hydrocarbon fuels would increase engine efficiency, due to a slightly higher density, the lack of an oxygen atom in the fuel molecule, and negligible water content. Whatever hydrocarbon was chosen, though, would have to replicate alcohol's coolant ability.

碳氢燃料缺乏氧原子（乙醇中的氧来源于羟基）

燃料的比冲主要由温度和气体相对分子量决定（还有燃烧室压强）。你说的产气量也就是气体相对分子量。气体相对分子量小比冲大，从这点上讲，结晶水有利于提高比冲。但加入结晶水会使燃气温度降低（同样质量的燃料产生的能量少了，而气体多了，所有更少的能量要分给更多的气体），从这点讲比冲降低了。综合起来怎么变化就要看哪个占主导了。从实际情况来看是加入结晶水比冲降低了。

不会不会不会不会。

结晶水分解是吸热反应。记得这点就够了。

固态火箭的比冲值多半低于液态，因为固态的氧化剂比液氧多很多没用的质量。水合物只会浪费更多。