In this work, the application of harmonic balance technique is demonstrated for transonic buffet cases. The method represents an alternative to time-marching simulations that are expensive complex flow Here applied on different test cases with inherently unsteady flows, i.e. two aerofoil configurations undergoing buffet. A gradient-based, variable time period used estimate frequency oscillation...

It is the purpose of this paper to introduce a computer software that is developed for the analysis of general multi degree of freedom rotor bearing systems with non-linear support elements. A numerical-analytical method for the prediction of steady state periodic response of large order nonlinear rotor dynamic systems is addressed which is based on the harmonic balance technique. By utilizing ...

Duffing harmonic oscillator is a common model for nonlinear phenomena in science and engineering. This paper presents He´s Energy Balance Method (EBM) for solving nonlinear differential equations. Two strong nonlinear cases have been studied analytically. Analytical results of the EBM are compared with the solutions obtained by using He´s Frequency Amplitude Formulation (FAF) and numerical solu...

In this continuation of a series of our earlier papers, we define a hypersurface h(x, t) = 0 in terms of the unknown vector x, and a monotonically increasing function Q(t) of a time-like variable t, to solve a system of nonlinear algebraic equations F(x) = 0. If R is a vector related to ∂h/∂x, we consider the evolution equation ẋ = λ [αR+βP], where P = F−R(F ·R)/‖R‖2 such that P ·R = 0; or ẋ = ...