Abstract
In this study non-normality of a thermo-acoustic heat engine has been investigated. The analytical formulation for the network model of a thermo-acoustic heat engine has been utilized to find the eigenvalues and eigenvectors for the acoustic velocity and pressure representations. Then for a specified number of eigenmodes, transient growth factor has been computed. Maximum growth factor has been calculated for different configurations: changing the stack length, length of the upstream and downstream ducts, temperature difference across the stack and plate spacing in the stack.