Colloidal nanocrystal superlattices as phononic crystals: plane wave expansion modeling of phonon band structure

RSC Advances ◽  
2016 ◽  
Vol 6 (50) ◽  
pp. 44578-44587 ◽  
Author(s):  
Seid M. Sadat ◽  
Robert Y. Wang
Keyword(s):  
Band Structure ◽  
Plane Wave ◽  
High Frequency ◽  
Three Dimensional ◽  
Organic Matrix ◽  
Phononic Crystals ◽  
Periodic Array ◽  
Plane Wave Expansion ◽  
Phonon Band ◽  
Nanocrystal Superlattices

Colloidal nanocrystal superlattices are a natural platform for high frequency three-dimensional phononic crystals (~102 GHz) because they consist of a periodic array of hard nanoparticles in a soft organic matrix.

scholarly journals Enhanced plane wave expansion analysis for the band structure of bulk modes in two-dimensional high-contrast solid–solid phononic crystals

2014 ◽  
Vol 12 (5) ◽  
pp. 487-492 ◽  
Author(s):  
Mohammadhosein Ghasemi Baboly ◽  
Yasser Soliman ◽  
Mehmet F. Su ◽  
Charles M. Reinke ◽  
Zayd C. Leseman ◽  
...  
Keyword(s):  
Band Structure ◽  
Plane Wave ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
High Contrast ◽  
Plane Wave Expansion ◽  
Wave Expansion

HIGH-FREQUENCY DIFFRACTION BY A SPHERE

1961 ◽  
Vol 39 (10) ◽  
pp. 1486-1494
Author(s):  
C. L. Tang
Keyword(s):  
Plane Wave ◽  
High Frequency ◽  
Rotational Symmetry ◽  
Asymptotic Series ◽  
Three Dimensional ◽  
Shadow Region ◽  
High Frequencies ◽  
Present Procedure ◽  
Dimensional Object

A systematic procedure is given for the determination of the asymptotic series directly from the Helmholtz equation and the boundary conditions for the field in the shadow region of a sphere illuminated by a plane wave at high frequencies. The first two terms in the series for the shadow region, including the regions near the axial caustic and the boundary layer near the surface of the sphere, are explicitly evaluated. The present procedure can be generalized to any smooth convex three-dimensional object with a rotational symmetry, illuminated by a plane wave in the direction of the axis of rotational symmetry.

Silencer for high-frequency turbocharger compressor noise via an acoustic straightener

2021 ◽  
Vol 263 (5) ◽  
pp. 1744-1755
Author(s):  
Pranav Sriganesh ◽  
Rick Dehner ◽  
Ahmet Selamet
Keyword(s):  
Wave Propagation ◽  
Plane Wave ◽  
High Frequency ◽  
Three Dimensional ◽  
Mean Flow ◽  
Analytical Treatment ◽  
Underlying Assumption ◽  
Wide Range ◽  
Plane Wave Propagation ◽  
Dimensional Wave

Decades of successful research and development on automotive silencers for engine breathing systems have brought about significant reductions in emitted engine noise. A majority of this research has pursued airborne noise at relatively low frequencies, which typically involve plane wave propagation. However, with the increasing demand for downsized turbocharged engines in passenger cars, high-frequency compressor noise has become a challenge in engine induction systems. Elevated frequencies promote multi-dimensional wave propagation rendering at times conventional silencer treatments ineffective due to the underlying assumption of one-dimensional wave propagation in their design. The present work focuses on developing a high-frequency silencer that targets tonal noise at the blade-pass frequency within the compressor inlet duct for a wide range of rotational speeds. The approach features a novel "acoustic straightener" that creates exclusive plane wave propagation near the silencing elements. An analytical treatment is combined with a three-dimensional acoustic finite element method to guide the early design process. The effects of mean flow and nonlinearities on acoustics are then captured by three-dimensional computational fluid dynamics simulations. The configuration developed by the current computational effort will set the stage for further refinement through future experiments.

scholarly journals Using PWE/FE Method to Calculate the Band Structures of the Semi-Infinite PCs: Periodic in x–y Plane and Finite in z -direction

2017 ◽  
Vol 42 (4) ◽  
pp. 735-742 ◽  
Author(s):  
Denghui Qian ◽  
Zhiyu Shi
Keyword(s):  
Finite Element ◽  
Band Structure ◽  
Plane Wave ◽  
Composite Structures ◽  
Phononic Crystal ◽  
Plane Wave Expansion ◽  
Fe Method ◽  
Band Structures ◽  
Wave Expansion ◽  
Elastic Composite

Abstract This paper introduces the concept of semi-infinite phononic crystal (PC) on account of the infinite periodicity in x-y plane and finiteness in z-direction. The plane wave expansion and finite element methods are coupled and formulized to calculate the band structures of the proposed periodic elastic composite structures based on the typical geometric properties. First, the coupled plane wave expansion and finite element (PWE/FE) method is applied to calculate the band structures of the Pb/rubber, steel/epoxy and steel/aluminum semi-infinite PCs with cylindrical scatters. Then, it is used to calculate the band structure of the Pb/rubber semi-infinite PC with cubic scatter. Last, the band structure of the rubbercoated Pb/epoxy three-component semi-infinite PC is calculated by the proposed method. Besides, all the results are compared with those calculated by the finite element (FE) method implemented by adopting COMSOL Multiphysics. Numerical results and further analysis demonstrate that the proposed PWE/FE method has strong applicability and high accuracy.

scholarly journals A study of the band structure in two-dimensional phononic crystals based on plane-wave algorithm

2003 ◽  
Vol 52 (3) ◽  
pp. 668
Author(s):  
Qi Gong-Jin ◽  
Yang Sheng-Liang ◽  
Bai Shu-Xin ◽  
Zhao Xun
Keyword(s):  
Band Structure ◽  
Plane Wave ◽  
Phononic Crystals ◽  
Two Dimensional
Sign in / Sign up

Export Citation Format

Share Document