Dimensionless groups Arrhenius group

The dimensionless group y is known as the Arrhenius number. Substitution of the dimensionless variables into the material and energy balances gives ... 

If the complete transient equations are considered, the important dimensionless groups of parameters can be formulated. Consider a first-order reaction with Arrhenius form of rate constant ... 

Here A is the pre-exponential factor, E is an effective activation energy or temperature coefficient for the overall reaction, R = 8.314 JK moP is the Gas Constant and T is the local absolute temperature. The quotient E/R has units of temperature and is sometimes known as the Arrhenius temperature It is a characteristic feature of combustion processes that if Ta is the ambient temperature, then Tatt> so that the group RTJE and, more generally, the scaled or dimensionless temperature RTIE are typically (very) small quantities in the systems of interest. 

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