Abstract :
The progression of chemical reactions is
determined by both thermodynamics and kinetics factors.
Micropyretic/combustion reaction is a cascade of many
chain chemical reactions and thermodynamics and kinetics
of the ignition reaction are expected to greatly affect the
overall reaction outcome. Furthermore, the stability of the
sequential reaction and its progression are correspondingly
changed once micropyretic parameters are changed.
Improper ignition of micropyretic reaction provides either
excessive or insufficient external energy, thus causes overheating
or extinguishing of the combustion front during
propagation and therefore the heterogeneous structures. To
achieve the homogeneous micropyretic reaction, it is
thought possible to control ignition energy. A numerical
study on the correlation of thermodynamics and kinetics
factors of ignition on the stable Ni + Al reaction and the
required ignition energy is reported in this study. The
influences of activation energy (E), enthalpy of the
micropyretic reaction (Q), pre-exponential factor (Ko),
thermal conductivity (K), heat capacity (Cp), and thermal
activity of the reactants and product, on the temperature/
heat loss at the ignition spot and the length of pre-heating
zone are respectively studied. It is found that the activation
energy and heat capacity have the most significant effects
on the ignition energy. The required ignition energy is
increased by 44.0% and 23.9%, respectively, when the
activation energy and the heat capacity are both increased
by 40.0%
