An Easy Method to Get Criterial Values of Frank-Kamenetskii Parameter for Infinite Plane Slab and Infinite Cylinder

Frank-Kamenetskii theory provided a dimensionless Frank-Kamenetskii parameter to express the risk of spontaneous ignition problem. And there is a criterial value which is the turning point of spontaneous ignition problem for different models. This paper first shows the basis theory of Frank-Kamenetskii and then get the exact criterial values of infinite plane slab model and infinite cylinder model with a more easy method. And with the same method, the more complicated sphere model is simplified, but the exact analytical solution of simplified ordinary differential equation still cannot be gotten. The numerical solution of other complicated model (include sphere model) would be discussed in the future.