Observation of Second-Harmonic Ion Bernstein Waves Excited by Fast-Wave Mode Conversion in the Microtor Tokamak

1984 ◽  
Vol 52 (18) ◽  
pp. 1609-1612 ◽  
Author(s):  
H. Park ◽  
N. C. Luhmann ◽  
W. A. Peebles ◽  
R. Kirkwood
Keyword(s):  
Mode Conversion ◽  
Second Harmonic ◽  
Wave Mode ◽  
Fast Wave ◽  
Bernstein Waves

Fast wave mode conversion in three-ion component plasmas

2008 ◽  
Author(s):  
Yevgen Kazakov ◽  
Ivan Pavlenko ◽  
Igor Girka ◽  
Boris Weyssow
Keyword(s):  
Mode Conversion ◽  
Wave Mode ◽  
Fast Wave

scholarly journals Full wave simulations of fast wave mode conversion and lower hybrid wave propagation in tokamaks

2004 ◽  
Vol 11 (5) ◽  
pp. 2473-2479 ◽  
Author(s):  
J. C. Wright ◽  
P. T. Bonoli ◽  
M. Brambilla ◽  
F. Meo ◽  
E. D’Azevedo ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Mode Conversion ◽  
Wave Mode ◽  
Lower Hybrid ◽  
Fast Wave ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Full Wave

scholarly journals Numerical Simulation on Micro-damage Detection In CFRP Composites Based on Nonlinear Ultrasonic Guided Waves

2021 ◽  
Keyword(s):  
Damage Detection ◽  
Composite Structures ◽  
Guided Waves ◽  
Second Harmonic ◽  
Wave Mode ◽  
Guided Wave ◽  
Reinforced Plastics ◽  
Matrix Cracks ◽  
Nonlinear Ultrasonic ◽  
Contact Acoustic Nonlinearity

Abstract. Micro-damages such as pores, closed delamination/debonding and fiber/matrix cracks in carbon fiber reinforced plastics (CFRP) are vital factors towards the performance of composite structures, which could collapse if defects are not detected in advance. Nonlinear ultrasonic technologies, especially ones involving guided waves, have drawn increasing attention for their better sensitivity to early damages than linear acoustic ones. The combination of nonlinear acoustics and guided waves technique can promisingly provide considerable accuracy and efficiency for damage assessment and materials characterization. Herein, numerical simulations in terms of finite element method are conducted to investigate the feasibility of micro-damage detection in multi-layered CFRP plates using the second harmonic generation (SHG) of asymmetric Lamb guided wave mode. Contact acoustic nonlinearity (CAN) is introduced into the constitutive model of micro-damages in composites, which leads to the distinct SHG compared with material nonlinearity. The results suggest that the generated second order harmonics due to CAN could be received and adopted for early damage evaluation without matching the phase of the primary waves.

Investigation of transcranial ultrasound delivery via Lamb wave mode conversion leveraging a transducer pair

2021 ◽  
Vol 150 (4) ◽  
pp. A32-A32
Author(s):  
Matteo Mazzotti ◽  
Eetu Kohtanen ◽  
Alper Erturk ◽  
Massimo Ruzzene
Keyword(s):  
Lamb Wave ◽  
Mode Conversion ◽  
Wave Mode ◽  
Transcranial Ultrasound

FAST WAVE HEATING VIA MODE CONVERSION AND ICRF SCALING TO REACTOR SIZE

1979 ◽  
pp. 121-126
Author(s):  
J.E. Scharer ◽  
B.D. McVey ◽  
D.T. Blackfield ◽  
J.B. Beyer ◽  
T.K. Mau
Keyword(s):  
Mode Conversion ◽  
Fast Wave ◽  
Wave Heating

scholarly journals Poroelastic property analysis of seismic low-frequency shadows associated with gas reservoirs

2020 ◽  
Vol 17 (3) ◽  
pp. 463-474
Author(s):  
Shengjie Li ◽  
Ying Rao
Keyword(s):  
Mode Conversion ◽  
Low Frequency ◽  
Simulation Method ◽  
Wave Mode ◽  
Pore Fluid ◽  
Fluid Distribution ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Reservoir Properties ◽  
Gas Bearing

Abstract Seismic low-frequency amplitude shadows have been widely used as a hydrocarbon indicator. This study investigates the effect of reservoir properties and seismic wave mode conversion on the characteristics of the low-frequency amplitude shadows in gas-bearing reservoirs. The target gas reservoirs are typically related to the lithology of tight sandstone with strong heterogeneity. Pore-fluid distribution within the reservoirs presents patchy saturation in the vertical and horizontal directions, and this patchy saturation easily induces low-frequency shadows beneath gas-bearing reservoirs. These low-frequency shadows are validated by using a poroelastic simulation method. The results of our field case-based study indicate that pore-fluid property, plus the thickness and heterogeneity of reservoirs are the key elements in the generation of low-frequency shadows. The results also indicate that the poroelastic simulation method can be used to effectively predict the spatial distribution of gas-bearing reservoirs, by directly verifying the low-frequency shadow phenomenon existing in the seismic data.

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