Design of Computational Aeroacoustic Codes

The objective of this chapter is to discuss how to design a computation code to simulate an aeroacoustic phenomenon. In previous chapters, many methods and elements of numerical computation were discussed. In this chapter, they are to be synthesized to form a computer simulation code. The basic elements/ingredients of a good simulation algorithm in computational aeroacoustics would consist of the following:

1. A computational model containing all essential physics of the aeroacoustic phe­nomenon

2. A properly chosen computational domain

3. A well-designed computational grid

4. A least dispersive and dissipative high-resolution time marching algorithm

5. A time step that ensures numerical stability and good resolution

6. A set of high-quality boundary conditions for both exterior and interior bound­aries

7. A properly chosen distribution of artificial selective damping to suppress the generation and propagation of spurious short waves

8. A set of properly prescribed initial conditions

15.1 Basic Elements of a CAA Code

Each of the eight elements in this list affects the simulation in some way. Some exert an influence on numerical stability. Some affect the accuracy and quality of the computed solution. Others control and influence the computation time. A more detailed consideration of some of these elements in this list is provided next.