A three-dimensional multi-block Newton-Krylov flow solver for the Euler equations has been developed for steady aerodynamic flows. The solution is computed through a Jacobian-free inexact-Newton method with an approximate-Newton method for startup. The linear system at each outer iteration is solved using a Generalized Minimal Residual (GMRES) Krylov subspace algorithm. An incomplete lower/uppe...

In the present paper, a new analytical technique is introduced for obtaining approximate periodic solutions of Helmholtz-Duffing oscillator. Modified Harmonic Balance Method (MHBM) is adopted as the solution method. A classical harmonic balance method does not apply directly for solving Helmholtz-Duffing oscillator. Generally, a set of difficult nonlinear algebraic equations is found when MHBM ...

Radio-frequency (RF) circuits exhibit several distinguishing characteristics that make them difficult to simulate using traditional SPICE transient analysis. The various extensions to the harmonic balance and shooting method simulation algorithms are able to exploit these characteristics to provide rapid and accurate simulation for these circuits. This paper is an introduction to RF simulation ...

Probe insertion technique is considered as an exclusively frequency domain approach. It has been developed to increase robustness of the harmonic balance method, when simulating autonomous circuits to avoid the DC degenerate solution. This technique evidences several good properties, for instance when simulating oscillators either employing high quality factor resonators or AC coupled ones. In ...

Amathematical model of a direct-fired continuous strip annealing furnace is developed. The first-principle model uses the heat balance to describe the dynamic behavior of the strip and the rolls. Themass and the enthalpy balance are employed to calculate themass, the composition, and the temperature of the flue gas. The heat conduction equation of the furnace wall is discretized bymeans of the ...

Very recently, Yildirim et al. [1] applied the so-called Hamiltonian approach (HA) to obtain analytical approximate solutions for three well-known nonlinear oscillators. The authors mentioned that this approach is a kind of energy method with a vast application in conservative oscillatory systems, and they applied the approach to nonlinear oscillators with rational and irrational elastic terms....

An analytical approximate technique for conservative nonlinear oscillators is proposed. This method is a modification of the generalized harmonic balance method in which analytical approximate solutions have a rational form. This approach gives us not only a truly periodic solution but also the frequency of motion as a function of the amplitude of oscillation. Three truly nonlinear oscillators ...

Rather than approach the parallelization of the harmonic balance simulation method numerically, a novel scheduling-oriented approach is described. The technique leverages circuit substructure to expose potential parallelism in the form of a directed, acyclic graph (dag) of computations. This dag is then allocated and scheduled using various linear clustering techniques. The result is a highly s...