In this chapter we perform the numerical simulations for acoustic field generated by air flowing over a cylinder. This problem is chosen to verify the accuracy of the developed solver. The acoustic fields are calculated for different Reynolds numbers
(1)
The density of air is . The dynamic viscosity is . Choose the diameter of the cylinder to be . Then, at the three given Reynolds numbers, the velocity can be calcuated from (1):
Reynolds number | 89,000 | 46,000 | 22,000 |
---|---|---|---|
Velocity (m/s) | 14.407102 | 7.446367 | 3.561306 |
Note
In examples/bulk/air run the following commands to obtain the above numbers:
./go velocity --density 1.225 --diameter 0.1 --dvisco 1.983e-5 --reynolds 89000
./go velocity --density 1.225 --diameter 0.1 --dvisco 1.983e-5 --reynolds 46000
./go velocity --density 1.225 --diameter 0.1 --dvisco 1.983e-5 --reynolds 22000
The bulk modulus of air is .