Incomplete acoustic time reversal, frequency shifting, and matched field processing

2021 ◽  
Vol 150 (4) ◽  
pp. A193-A193
Author(s):  
David R. Dowling
Keyword(s):  
Time Reversal ◽  
Matched Field Processing ◽  
Reversal Frequency ◽  
Frequency Shifting

Matched-field processing using time-reversal concept in a range-dependent environment

2012 ◽  
Vol 131 (4) ◽  
pp. 3239-3239 ◽  
Author(s):  
Kunde Yang ◽  
Tongwei Zhang ◽  
Yuanliang Ma
Keyword(s):  
Time Reversal ◽  
Matched Field Processing

Temporal Focusing Effects of Time-Reversal Frequency Diverse Array Antenna

2019 ◽  
Vol 18 (9) ◽  
pp. 1858-1862 ◽  
Author(s):  
Jie Cheng ◽  
Wen-Qin Wang ◽  
Hui Chen ◽  
Shilong Ji
Keyword(s):  
Time Reversal ◽  
Array Antenna ◽  
Temporal Focusing ◽  
Reversal Frequency ◽  
Frequency Diverse Array

Determination of eddy current losses and hysteresis losses in magnetic circuits of electrical machines

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov
Keyword(s):  
Eddy Current ◽  
Magnetization Reversal ◽  
Eddy Currents ◽  
Technical Problem ◽  
Electrical Machines ◽  
Eddy Current Losses ◽  
Hysteresis Losses ◽  
Magnetic Circuits ◽  
Core Losses ◽  
Reversal Frequency

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.

Time Reversal in Lossy Material: An Assessment

PIERS Online ◽  
2006 ◽  
Vol 3 (8) ◽  
pp. 1259-1263
Author(s):  
Ian Scott ◽  
Ana Vukovic ◽  
Phillip Sewell
Keyword(s):  
Time Reversal ◽  
Lossy Material

Thermoacoustic imaging using time reversal

2007 ◽  
Author(s):  
Hubert Grün ◽  
Christian Hofer ◽  
Markus Haltmeier ◽  
Günther Paltauf ◽  
Peter Burgholzer
Keyword(s):  
Time Reversal ◽  
Thermoacoustic Imaging
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