scholarly journals Interactions between scales in wall turbulence: phase relationships, amplitude modulation and the importance of critical layers

2021 ◽  
Vol 914 ◽  
Author(s):  
Ian Jacobi ◽  
Daniel Chung ◽  
Subrahmanyam Duvvuri ◽  
Beverley J. McKeon
Keyword(s):  
Amplitude Modulation ◽  
Wall Turbulence ◽  
Critical Layers ◽  
Phase Relationships

Abstract

A role for amplitude modulation phase relationships in speech rhythm perception

2014 ◽  
Vol 136 (1) ◽  
pp. 366-381 ◽  
Author(s):  
Victoria Leong ◽  
Michael A. Stone ◽  
Richard E. Turner ◽  
Usha Goswami
Keyword(s):  
Amplitude Modulation ◽  
Rhythm Perception ◽  
Speech Rhythm ◽  
Phase Relationships ◽  
Modulation Phase

scholarly journals Large-scale amplitude modulation of the small-scale structures in turbulent boundary layers

2009 ◽  
Vol 628 ◽  
pp. 311-337 ◽  
Author(s):  
ROMAIN MATHIS ◽  
NICHOLAS HUTCHINS ◽  
IVAN MARUSIC
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Amplitude Modulation ◽  
Large Scale ◽  
Wall Turbulence ◽  
Small Scale ◽  
Supporting Evidence ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Near Wall

In this paper we investigate the relationship between the large- and small-scale energy-containing motions in wall turbulence. Recent studies in a high-Reynolds-number turbulent boundary layer (Hutchins & Marusic, Phil. Trans. R. Soc. Lond. A, vol. 365, 2007a, pp. 647–664) have revealed a possible influence of the large-scale boundary-layer motions on the small-scale near-wall cycle, akin to a pure amplitude modulation. In the present study we build upon these observations, using the Hilbert transformation applied to the spectrally filtered small-scale component of fluctuating velocity signals, in order to quantify the interaction. In addition to the large-scale log-region structures superimposing a footprint (or mean shift) on the near-wall fluctuations (Townsend, The Structure of Turbulent Shear Flow, 2nd edn., 1976, Cambridge University Press; Metzger & Klewicki, Phys. Fluids, vol. 13, 2001, pp. 692–701.), we find strong supporting evidence that the small-scale structures are subject to a high degree of amplitude modulation seemingly originating from the much larger scales that inhabit the log region. An analysis of the Reynolds number dependence reveals that the amplitude modulation effect becomes progressively stronger as the Reynolds number increases. This is demonstrated through three orders of magnitude in Reynolds number, from laboratory experiments at Reτ ~ 103–104 to atmospheric surface layer measurements at Reτ ~ 106.

Experimental evidence of amplitude modulation in permeable-wall turbulence

2020 ◽  
Vol 887 ◽  
Author(s):  
Taehoon Kim ◽  
Gianluca Blois ◽  
James L. Best ◽  
Kenneth T. Christensen
Keyword(s):  
Experimental Evidence ◽  
Amplitude Modulation ◽  
Wall Turbulence ◽  
Permeable Wall ◽  
Image Position

Synthesis of 16 Quadrature Amplitude Modulation Using Polarization-Multiplexing QPSK Modulator

2011 ◽  
Vol E94-B (7) ◽  
pp. 1809-1814 ◽  
Author(s):  
Isao MOROHASHI ◽  
Takahide SAKAMOTO ◽  
Masaaki SUDO ◽  
Atsushi KANNO ◽  
Akito CHIBA ◽  
...  
Keyword(s):  
Amplitude Modulation ◽  
Quadrature Amplitude Modulation ◽  
Polarization Multiplexing
Sign in / Sign up

Export Citation Format

Share Document