Calculation method for acoustic damping characteristics of mixed head of thrust chamber of afterburning engine

The invention provides a method for calculating sound damping characteristics of a mixed head of a thrust chamber of an afterburning engine. The method is used for solving the technical problems that an existing mixed head sound damping calculation method is low in precision, and an analysis result is greatly different from an actual situation. The method comprises the following steps: firstly, extracting geometric blocks of a fuel gas flow channel according to structural parameters of the fuel gas flow channel of the thrust chamber; importing the geometric blocks into an acoustic solver to obtain an acoustic solution domain of each geometric block; then, based on a rectifier grid boundary impedance equation, a nozzle impedance equation and a source item equation of background average flow, an impedance value and a dissipation source item are obtained through calculation; and finally, the impedance value and the dissipation source item are respectively applied to respective computational domains, and the opti