Results 11 to 20 of about 130,525 (161)

Prescribed performance control approaches, applications and challenges: A comprehensive survey

Asian Journal of Control, Volume 25, Issue 1, Page 241-261, January 2023., 2023
Abstract As to control systems, transient performance is as important as steady‐state performance. For some special dynamic systems, transient performance is a more prior index in comparison with the steady‐state one. Prescribed performance control (PPC) has been proved to be a powerful tool that guarantees control system outputs/errors with desired ...
Xiangwei Bu
wiley   +1 more source

Phonon Engineering of Micro‐ and Nanophononic Crystals and Acoustic Metamaterials: A Review

Small Science, Volume 3, Issue 1, January 2023., 2023
Phononic crystals and acoustic metamaterials with phonon wave manipulation capabilities have attracted considerable attention. This review summarizes the progress and identifies gaps in phonon engineering at the micro‐ and nanoscales using phononic crystals and metamaterials due to their potential significance in modern electronic applications.
Jihong Ma
wiley   +1 more source

Role of corner flow separation in unsteady dynamics of hypersonic flow over a double wedge geometry [PDF]

Physics of Fluids, 2021, 2021
This study investigates the origin and sustenance of self induced oscillations of shock structures in a hypersonic flow over a double wedge configuration. Previously, various researchers have considered the double wedge flow configuration for inviscid flow with variations of different inflows as well as geometric parameters such as inflow Mach number ,
arxiv   +1 more source

Code-Verification Techniques for Hypersonic Reacting Flows in Thermochemical Nonequilibrium [PDF]

Journal of Computational Physics, 425 (2021), 2020
The study of hypersonic flows and their underlying aerothermochemical reactions is particularly important in the design and analysis of vehicles exiting and reentering Earth's atmosphere. Computational physics codes can be employed to simulate these phenomena; however, verification of these codes is necessary to certify their credibility.
arxiv   +1 more source

High-Order Methods for Hypersonic Flows with Strong Shocks and Real Chemistry [PDF]

, 2022
We compare high-order methods including spectral difference (SD), flux reconstruction (FR), the entropy-stable discontinuous Galerkin spectral element method (ES-DGSEM), modal discontinuous Galerkin methods, and WENO to select the best candidate to simulate strong shock waves characteristic of hypersonic flows. We consider several benchmarks, including
arxiv   +1 more source

Numerical modelling of imposed magnetohydrodynamic effects in hypersonic flows [PDF]

, 2022
Weakly ionised plasmas, formed in high enthalpy hypersonic flows, can be actively manipulated via imposed magnetic fields - a concept termed magnetohydrodynamic (MHD) flow control. Imposed MHD effects, within flows which exhibit multiple shock interactions, are consequential for emerging aerospace technologies: including aerodynamic control via ...
arxiv   +1 more source

Discontinuous Galerkin Methods for Hypersonic Flows [PDF]

arXiv, 2023
In recent years, high-order discontinuous Galerkin (DG) methods have emerged as an attractive approach for numerical simulations of compressible flows. This paper presents an overview of the recent development of DG methods for compressible flows with particular focus on hypersononic flows. First, we survey state-of-the-art DG methods for computational
arxiv  

Generalized Newton-Busemann Law For Two-Dimensional Steady Hypersonic-limit Euler Flows Passing Ramps With Skin-Frictions [PDF]

arXiv, 2023
By considering Radon measure solutions for boundary value problems of stationary non-isentropic compressible Euler equations on hypersonic-limit flows passing ramps with frictions on their boundaries, we construct solutions with density containing Dirac measures supported on the boundaries of the ramps, which represent the infinite-thin shock layers ...
arxiv  

Numerical Investigation of Chemically Reacting Rarefied Hypersonic Flows Over A Backward-Facing Step [PDF]

arXiv, 2021
The present study employs the Direct Simulation Monte Carlo (DSMC) method, a widely used numerical method for studying non-continuum flows, to investigate the flow characteristics of a chemically reacting hypersonic flow over a backward-facing step. This work explores the effects of the Knudsen number on the behaviour of rarefied flow and compares the ...
arxiv  

Nanosecond Hyperquenching for Electron Cryo‐Microscopy Without Air‐Water Interface Artifacts

Chemistry – A European Journal, EarlyView.
A novel method for the ultrafast vitrification of the biological assemblies is assayed by the electron cryotomography. Protein specimens prepared by this method inherently lack the spatial/structural artifacts, which derive from the surface tension at the air‐water interface (AWI).
Utz H. Ermel, Harald Schwalbe, Alexey V. Cherepanov   +2 more
wiley   +1 more source