Optimization of blowing in a convergent-divergent nozzle for noise reduction

This paper describes the use of an adjoint method for aerodynamic and aeroacoustic optimization. An adjoint method is used to find an optimum distribution of blowing in a convergent-divergent nozzle to achieve a desired pressure distribution in the nozzle with the goal of noise reduction. This paper describes the development of a three-dimensional adjoint method for simulations on multi-block structured grids. An example is given where a particular blowing distribution is first imposed. The resulting pressure distribution is used as the target distribution with no blowing as an initial condition. It is shown that after several cycles, a blowing distribution is obtained that provides the desired or target pressure distribution.