Impulse theoretical consideration

The present consideration is limited to the effect of mixture ratio upon performance as measured simply by specific impulse. Since maximum enthalpy of reaction and minimum product molecular weight will not occur at the same mixture ratio one would predict, priori that the optimum mixture ratio should fall between the mixture ratio of maximum enthalpy of reaction and the mixture ratio of lowest product density. The maximum enthalpy of reaction occurs at the stoichiometric mixture ratio, that ratio at which there is theoretically just sufficient oxidizer to completely oxidize the fuel elements. Any excess fuel or oxidizer essentially acts as a diluent. The maximum temperature thus should fall at the stoichiometric point. 

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