Abstract: An integrated optimization design method for nozzle configuration and splitter radial location was proposed using B-spline curve， computational fluid dynamics method and improved particle swarm optimization. Then the proposed method was implemented to optimize a splitter mixing exhaust system. The results indicate that the optimized system has better mass flux distribution than the original model. The difference of bypass ratio between optimized model and design value is 2.8%. In aerodynamic performance aspect， the thrust of optimized splitter mixing exhaust system is 1.061 times as the original model， and the total pressure recovery coefficient increases to 0.995. Under the off-design conditions， compared with the original model， the total pressure recovery coefficients of optimized model increase respectively by 0.7% and 0.4%， and the thrust increases respectively by 1.2% and 2.7% .

Key words: splitter mixing exhaust system, B-spline curve, splitter location, nozzle configuration, aerodynamic performance, bypass ratio