On the connection between the aerodynamic and acoustic characteristics of coaxial jets

The results are given of experimental investigations into the distributions of the mean and pulsation velocities in the mixing region of isothermal coaxial jets with ordinary velocity profile and “inverted” velocity profile (velocity of the outer flow greater than that of the inner flow). These results are used in a comparative estimate of the noise of coaxial jets with different initial velocity profiles, and a comparison is made with the data of experimental investigations of the noise.