Alexander Lukin^1,*, Oğuz Gülseren²

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1763-1779, 2022, DOI:10.32604/fdmp.2022.022016

Abstract Carbyne-enriched nanomaterials are of current interest in nanotechnology-related applications. The properties of these nanomaterials greatly depend on their production process. In particular, structural self-organization and auto-synchronization of nanostructures are typical phenomena observed during the growth and heteroatom-doping of carbyne-enriched nanostructured metamaterials by the ion-assisted pulse-plasma deposition method. Accordingly, fine tuning of these processes may be seen as the key step to the predictive designing of carbyne-enriched nano-matrices with improved properties. In particular, we propose an innovative concept, connected with application of the vibrational-acoustic effects and based on universal Cymatics mechanisms. These effects are used to induce vibration-assisted self-organized wave patterns… More >

Abdelkarim Hegab^*, Faisal Albatati, Mohammed Algarni

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 437-468, 2021, DOI:10.32604/cmes.2021.014690

Abstract In this paper, analytical, computational, and experimental studies are integrated to examine unsteady acoustic/vorticity transport phenomena in a solid rocket motor chamber with end-wall disturbance and side-wall injection. Acoustic-fluid dynamic interactions across the chamber may generate intense unsteady vorticity with associated shear stresses. These stresses may cause scouring and, in turn, enhance the heat rate and erosional burning of solid propellant in a real rocket chamber. In this modelling, the unsteady propellant gasification is mimicked by steady-state flow disturbed by end-wall oscillations. The analytical approach is formulated using an asymptotic technique to reduce the full governing equations. The equations that… More >

Peter Hess, Alexey M. Lomonosov, AndrAC Moura, Peter V. Grigoriev

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 3-4, 2011, DOI:10.3970/icces.2011.020.003

Abstract Crack generation by the steep shock fronts of laser-induced nonlinear surface acoustic wave (SAW) pulses and their nondestructive evaluation (NDE) by short linear SAW pulses was studied experimentally and theoretically. With the contactfree laser-based photoacoustic pump-probe technique, nondestructive testing could be extended to the characterization of elastic-shock-generated partially closed microcracks in the range of tens of micrometers.

By numerical simulations the propagation of thermoelastically launched broadband SAW pulses in nonlinear media and the initiation of crack growth is described. The characteristic features of SAW profiles in linear media, nonlinear media with quadratic nonlinearity, and nonlinear media with crack nucleation… More >

Carlos J. S. Alves, Pedro R. S. Antunes¹

CMC-Computers, Materials & Continua, Vol.2, No.4, pp. 251-266, 2005, DOI:10.3970/cmc.2005.002.251

Abstract In this work we show the application of the Method of Fundamental Solutions(MFS) in the determination of eigenfrequencies and eigenmodes associated to wave scattering problems. This meshless method was already applied to simple geometry domains with Dirichlet boundary conditions (cf. Karageorghis (2001)) and to multiply connected domains (cf. Chen, Chang, Chen, and Chen (2005)). Here we show that a particular choice of point-sourcescan lead to very good results for a fairly general type of domains. Simulations with Neumann boundary conditionare also considered. More >