The advent, during the first decade of the 21st century, of the concept of acoustic metamaterial has disclosed an incredible potential of development for breakthrough technologies. Unfortunately, the extension of the same concepts to aeroacoustics has turned out to be not a trivial task, because of the different structure of the governing equations, characterized by the presence of the background aerodynamic convection. Some of the approaches recently introduced to circumvent the problem are biased by a fundamental assumption that makes the actual realization of devices extremely unlikely: the metamaterial should guarantee an adapted background aerodynamic convection in order to modify suitably the acoustic field and obtain the desired effect, thus implying the porosity of the cloaking device. In the present paper, we propose an interpretation of the metamaterial design that removes this unlikely assumption, focusing on the identification of an aerodynamically-impermeable metamaterial capable of reproducing the surface impedance profile required to achieve the desired scattering abatement. The attention is focused on a moving obstacle impinged by an acoustic perturbation induced by a co-moving source. The problem is written in a frame of reference rigidly connected to the moving object to couple the convective wave equation in the hosting medium with the inertially-anisotropic wave operator within the cloak. The problem is recast in an integral form and numerically solved through a boundary-field element method. The matching of the local wave vector is used to derive a convective design of the metamaterial applicable to the specific problem analyzed. Preliminary numerical results obtained under the simplifying assumption of a uniform aerodynamic flow reveal a considerable enhancement of the masking capability of the convected design. The numerical method developed shows a remarkable computational efficiency, completing a simulation of the entire field in a few minutes on mid-end workstations. The results are re-interpreted in term of boundary impedance, assuming a locally-reacting behavior of the outer boundary of the cloaking layer. The formulation is currently being extended to the analysis of arbitrarily complex external flows in order to remove the limitation of the background uniform stream in the host.
from #Medicine via ola Kala on Inoreader http://ift.tt/1NP9NFs
via IFTTT
Αρχειοθήκη ιστολογίου
-
►
2023
(138)
- ► Φεβρουαρίου (74)
- ► Ιανουαρίου (64)
-
►
2022
(849)
- ► Δεκεμβρίου (61)
- ► Σεπτεμβρίου (74)
- ► Φεβρουαρίου (65)
-
►
2021
(2936)
- ► Δεκεμβρίου (59)
- ► Σεπτεμβρίου (180)
- ► Φεβρουαρίου (325)
-
►
2020
(1624)
- ► Δεκεμβρίου (293)
- ► Σεπτεμβρίου (234)
- ► Φεβρουαρίου (28)
-
►
2019
(13362)
- ► Δεκεμβρίου (19)
- ► Σεπτεμβρίου (54)
- ► Φεβρουαρίου (5586)
- ► Ιανουαρίου (5696)
-
►
2018
(66471)
- ► Δεκεμβρίου (5242)
- ► Σεπτεμβρίου (5478)
- ► Φεβρουαρίου (4835)
- ► Ιανουαρίου (5592)
-
►
2017
(44259)
- ► Δεκεμβρίου (5110)
- ► Σεπτεμβρίου (5105)
-
▼
2016
(7467)
- ► Δεκεμβρίου (514)
- ► Σεπτεμβρίου (1038)
-
▼
Μαΐου
(630)
-
▼
Μαΐ 26
(50)
- Information, Vol. 7, Pages 29: Measuring Knowledge...
- Remote Sensing, Vol. 8, Pages 449: MERIS Phytoplan...
- Energies, Vol. 9, Pages 411: Simultaneous Optimiza...
- Metals, Vol. 6, Pages 127: The Effects of Al and T...
- Microarrays, Vol. 5, Pages 11: Living Cell Microar...
- Aerospace, Vol. 3, Pages 15: Theoretical and Numer...
- Universe, Vol. 2, Pages 8: Black Holes and Exotic ...
- Atmosphere, Vol. 7, Pages 75: Stratospheric Aeroso...
- IJMS, Vol. 17, Pages 809: The miRacle in Pancreati...
- IFC(EDITORIAL BOARD)
- Potential Role of Epigenetic Mechanism in Manganes...
- Fibers, Vol. 4, Pages 18: Glass Fibre Strength—A R...
- Sustainability, Vol. 8, Pages 502: The Environment...
- Sustainability, Vol. 8, Pages 508: Impact of Inter...
- IJERPH, Vol. 13, Pages 534: Dissipation and Residu...
- Energies, Vol. 9, Pages 410: Development of a Nove...
- Sensors, Vol. 16, Pages 759: Computer-Aided Sensor...
- Applied Sciences, Vol. 6, Pages 161: Isolation, Id...
- Energies, Vol. 9, Pages 412: Analytical Model for ...
- JMSE, Vol. 4, Pages 37: Quantitative Estimates of ...
- Sustainability, Vol. 8, Pages 507: Quantitative St...
- Algorithms, Vol. 9, Pages 36: Robust Hessian Local...
- Risks, Vol. 4, Pages 16: Spouses’ Dependence acros...
- Tailored message interventions versus typical mess...
- Haemorrhoidal artery ligation versus rubber band l...
- Laparoscopic distal pancreatectomy for pancreatic ...
- Statin-induced liver Injury in an area endemic for...
- Recurrence of solid pseudopapillary neoplasms of t...
- The role of hepatitis E virus infection in Adult A...
- Postinfectious and sporadic functional gastrointes...
- Age-dependent characteristics of feedback evaluati...
- IJMS, Vol. 17, Pages 378: A Theoretical Study of t...
- Radiologic and Clinicopathologic Findings of Infla...
- Lesion Size and Iodine Quantification to Distingui...
- Low-Contrast and Low-Radiation Dose Protocol in Ca...
- Multivariate Analysis of Pleural Invasion of Perip...
- Dual-Energy CT Characteristics of Parathyroid Aden...
- Accelerated Brain Atrophy on Serial Computed Tomog...
- The Initial Exploration of Adamkiewicz Artery Comp...
- A Liver Phantom Study: CT Radiation Dose Reduction...
- Computed Tomography Perfusion of Prostate Cancer: ...
- Apparent Diffusion Coefficient and Dynamic Contras...
- Primary Extremity Liposarcoma: MRI Features, Histo...
- Beak-Like Extension of the Pancreatic Uncinate Pro...
- Retrospective Assessment of Histogram-Based Diffus...
- Evaluation of Lung Radiofrequency Ablation With Du...
- Iterative Reconstruction Results in Larger Compute...
- Symmetry, Vol. 8, Pages 39: A PT -Symmetric Dual-C...
- Microsatellite instability as a predictive factor ...
- Targeting the ecology within: The role of the gut–...
-
▼
Μαΐ 26
(50)
- ► Φεβρουαρίου (793)
Αναζήτηση αυτού του ιστολογίου
Εγγραφή σε:
Σχόλια ανάρτησης (Atom)
-
Αλέξανδρος Γ. Σφακιανάκης Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,0030693260717...
-
heory of COVID-19 pathogenesis Publication date: November 2020Source: Medical Hypotheses, Volume 144Author(s): Yuichiro J. Suzuki ScienceD...
-
Alimentary Pharmacology &Therapeutics, EarlyView. https://ift.tt/2qECBIJ
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου
Σημείωση: Μόνο ένα μέλος αυτού του ιστολογίου μπορεί να αναρτήσει σχόλιο.