Sensitivity of temperature rates

in combustion modelling, the important feature is not a species concentration but the time to ignition, the maximum temperature rise or simply the critical ignition temperature. Frequently, temperature is a measured quantity in an experiment since measuring species concentrations is more difficult, especially for radicals. Therefore, the sensitivity of the rate of change of temperature to a change in the rate parameters is of importance. If the reduced model is required only to produce accurate temperature profiles then the temperature sensitivities become useful. This does not mean, however, that in this case mechanism reduction can be based on temperature rate sensitivities alone, and overall rate sensitivities should also be considered. 

In the example which follows it is calculated separately from the usual rate sensitivities and is a simple one-dimensional array. Another approach would be to treat temperature as though it were a concentration, and to include it in the eigenvector/eigenvalue analysis. 

---