Sharif Digital Repository

Nonlinear ultrasound modeling is finding an increasing number of applications in both medical and industrial areas where due to high pressure amplitudes the effects of nonlinear propagation are no longer negligible. Taking nonlinear effects into account makes the ultrasound beam analysis more accurate in these applications. One of the most widely used nonlinear models for propagation of 3D diffractive sound beams in dissipative media is the KZK (Khokhlov, Kuznetsov, Zabolotskaya) parabolic nonlinear wave equation. Various numerical algorithms have been developed to solve the KZK equation. Generally, these algorithms fall into one of three main categories: frequency domain, time domain and... 

Purpose - The purpose of this paper is to examine the cross-coupled responses of a coupled rotor-fuselage flight dynamic simulation model, including a finite-state inflow aerodynamics and a coupled flap-lag and torsion flexible blade structure. Design/methodology/approach - The methodology is laid out based on model development for an articulated main rotor, using the theories of aeroelastisity, finite element and finite-state inflow formulation. The finite-state inflow formulation is based on a 3D unsteady Euler-based concepts presented in the time domain. The most advantages of the model are the capability of modeling dynamic wake effects, tip losses and skewed wake aerodynamics. This is,...