| 摘要 |
In order to reduce the noise produced by counterrotating aircraft propellers, each propeller can be provided with a different number of blades (the numbers of blades being in the range 3, 5, 7, 8, 11, 13, 15 and 17). Mathematical relationships relating to the number of blades each propeller has and the respective speeds of rotation of the propellers, are discussed in detail in the context of noise production. <IMAGE> |
