Numerical Modeling using the Nonlinear Progressive Wave
Equation (NPE)
Outdoor
Sound Propagation
| Finally, Figure 11 displays the depth-averaged spectrum for linear and nonlinear propagation for each NPE moving frame. In the nonlinear case, harmonics are generated and rapidly attenuated. Moreover, parametric interaction effects lead to a frequency shift of the depth-averaged spectrum toward lower frequencies. |
Fig. 11 : Depth-averaged spectrum versus range for linear
(left subplot) and nonlinear (right subplot) acoustic propagation.