A design method of two-dimensional (2-D) convergent nozzle was developed to meet core and bypass mass flux requirements of mixed flow turbofan engine.A matching method for core and bypass mass flux based on three-dimensional (3-D) viscous numerical simulation was proposed.Non-linear dimensionless mass flux matching equations for core and bypass channel with 2-D nozzle were formulated.Solving procedure of the non-linear equations was presented.Numerical simulation and matching results for some nozzle cases indicate that : (1) The method for solving the non-linear mass flux equations is effective

geometric parameters could be determined quickly for 2-D convergent nozzle.(2) Nozzle length and throat area properly play a key role for the required nozzle gross thrust.A nozzle with greater length and smaller throat area has greater gross thrust and better efficiency.