An adaptive simulation model has been developed by means of modification factors.A modified conjugate gradient algorithm is employed for solving the nonlinear programming problem in the model.According to the parameter measurements of the engine on test rig and in flight

the component characteristics of the engine are rectified by the adaptive model

as a result

outputs of the model are in accordance with the measurements.As an example

the method provided was adopted to rectify the parameters in the simulation model of a given twin-spool reheated turbojet engine

and the simulation achieved satisfactory accuracy.