in English An introduction is given to the lattice Boltzmann method and its background, with a view towards acoustic applications of the method. To make a larger range of acoustic applications possible, a point source method is proposed. This point source is applied to simulate cylindrical waves and plane waves, and is shown to give a very good numerical result compared with analytic solutions ...

Structural responses to severe loads such as due to typhoons and earthquakes are very complicated, with nonlinear and non-stationary characteristics. When external forces are applied to the structure, vibrations of different frequencies and magnitudes are excited. If any of the vibrations cannot be damped within a reasonable period of time, damage to the structure is inevitable. The damage woul...

In order to avoid the damage of dump target Future Circular Collider’s proton ring, beam will be swept over its surface using dilution kickers oscillating in x/y planes with 90∘ phase difference, and an amplitude changing time, thereby creating a spiral-like pattern. The natural time-dependence is exponential decay damped circuit, which results decreasing pitch, increasing energy deposition den...

this paper presents the effects of geometric tolerances on the rotating shafts natural frequencies. due to modeling the tolerances, a code is written in matlab 2013 software that produces deviated points. deviated points are controlled by different geometric tolerances, including cylindricity, total run-out and coaxiality tolerances. final surfaces and models passing through the points are crea...

We show how pattern formation in Faraday waves may be manipulated by varying the harmonic content of the periodic forcing function. Our approach relies on the crucial influence of resonant triad interactions coupling pairs of critical standing wave modes with damped, spatiotemporally resonant modes. Under the assumption of weak damping and forcing, we perform a symmetry-based analysis that reve...

This article presents investigations of partial discharges (PD) in a high voltage cable system using different voltage shapes and frequencies. The two voltage sources which were used for energizing the cable system, are 50 Hz alternating current (AC) generated by a high voltage transformer and damped alternating current (DAC). Both systems can be used for PD detection with use of a standard PD ...

We experimentally study the nonlinear fluid damping of a rigid but elastically mounted pitching wing in absence freestream flow. The dynamics elastic mount are simulated using cyber-physical system. perturb and measure coefficient from damped oscillations over large range frequencies, amplitudes, pivot locations sweep angles. A universal scaling is proposed to incorporate all these parameters. ...

We study a generic model of globally coupled rotors that includes the effects of noise, phase shift in the coupling, and distributions of moments of inertia and natural frequencies of oscillation. As particular cases, the setup includes previously studied SakaguchiKuramoto, Hamiltonian and Brownian mean-field, and Tanaka-Lichtenberg-Oishi and AcebrónBonilla-Spigler models. We derive an exact so...

In this study, the natural frequencies and mode shapes of beams without cracks and cracked Timoshenko beams is calculated with different boundary conditions using finite element method. The energy method is used to solve the equations. Hardness and softness matrices for Timoshenko beam without crack are obtained by solving the potential and kinetic energy equations. Then for investigation of cr...

This study introduces the Differential Transform Method (DTM) in the analysis of the free vibration response of a rotating closed section composite, Timoshenko beam, which features material coupling between flapwise bending and torsional vibrations due to ply orientation. The governing differential equations of motion are derived using Hamilton’s principle and solved by applying DTM. The natura...