双圆弧喷管的型面设计。根据燃烧室的相关参数和喷管的背压可以设计出具有良好工作性能的双圆弧喷管，该喷管是基于特征线法的一种简化，方便加工。-Profile design of double circular nozzle. According to the relevant parameters of the combustion chamber and the nozzle back pressure can design of double circular nozzle having a g