In this paper,the current status of stealthy technology and infrared stealthy technology are presented,the features of turbofan engines and their superiority in the infrared stealthy of aircrafts are described in detail and the application prospect of the turbofan engines on stealthy aircrafts is analyzed.

The convergence problems of solving the nonlinear equations of aero turbine engines were study in detail,the common non-convergence cases were given and the mechanism was analyzed,based on Newton method,an advanced solutions for overcoming the common non-convergence problems was presented:variable step Newton method(VSN).