Transmission loss measurement of acoustic material using time-domain pulse-separation method (L)

2011 ◽  
Vol 129 (4) ◽  
pp. 1681-1684 ◽  
Author(s):  
Liang Sun ◽  
Hong Hou
Keyword(s):  
Time Domain ◽  
Transmission Loss ◽  
Separation Method ◽  
Loss Measurement ◽  
Pulse Separation

Transmission loss measurement in time domain using an impulse technique in ducts

1997 ◽  
Vol 102 (5) ◽  
pp. 3145-3145
Author(s):  
Andre L. Cherman ◽  
Roberto A. Tenenbaum
Keyword(s):  
Time Domain ◽  
Transmission Loss ◽  
Loss Measurement

Transmission loss measurement of multilayered partitions in time domain

1998 ◽  
Vol 103 (5) ◽  
pp. 2788-2788
Author(s):  
Andre L. Cherman ◽  
Roberto A. Tenenbaum
Keyword(s):  
Time Domain ◽  
Transmission Loss ◽  
Loss Measurement

A CFD APPROACH TO THE COMPUTATION OF THE ACOUSTIC RESPONSE OF EXHAUST MUFFLERS

2005 ◽  
Vol 13 (02) ◽  
pp. 301-316 ◽  
Author(s):  
A. BROATCH ◽  
X. MARGOT ◽  
A. GIL ◽  
F. D. DENIA
Keyword(s):  
Numerical Solution ◽  
Time Domain ◽  
Cfd Simulation ◽  
Transmission Loss ◽  
Three Dimensional ◽  
Alternative Procedure ◽  
Acoustic Response ◽  
Frequency Domains ◽  
The Time Domain ◽  
Numerical Approaches

The study of the three-dimensional acoustic field inside an exhaust muffler is usually performed through the numerical solution of the linearized equations. In this paper, an alternative procedure is proposed, in which the full equations are solved in the time domain. The procedure is based on the CFD simulation of an impulsive test, so that the transmission loss may be computed and compared with measurements and other numerical approaches. Also, the details of the flow inside the muffler may be studied, both in the time and the frequency domains. The results obtained compare favorably with a conventional FEM calculation, mostly in the ability of the procedure to account for dissipative processes inside the muffler.

Investigation on the effects of resistive loading on wrapped bow-tie antennas

2019 ◽  
Vol 11 (4) ◽  
pp. 390-400 ◽  
Author(s):  
Doojin Lee ◽  
George Shaker ◽  
William Melek
Keyword(s):  
Numerical Analysis ◽  
Time Domain ◽  
Group Delay ◽  
Transmission Loss ◽  
Flexible Substrate ◽  
Resistive Loading ◽  
Communication Ability ◽  
Radar Applications ◽  
The Time Domain ◽  
Bow Tie

AbstractThe pulse radiating characteristic of a wrapped bow-tie antenna (WBA) and wrapped resistively loaded bow-tie antenna (WRLBA) is presented for impulse radar applications in this paper. The numerical analysis of the WRLBA is performed by comparing that of the WBA. The wrapped antennas are realized on a flexible substrate. The antennas are fed by an impedance tapered balun, which has an overall transmission loss of −1.4 dB over the balun length. The characteristics of the resistive loading to the wrapped antenna, such as reflection coefficient, reflected pulse in the time domain, voltage standing wave ratio, and input impedance, are experimentally investigated and compared with simulated results. The fidelity factor of the radiated electric field on the boresight direction for the WBA and WRLBA is calculated as 0.82 and 0.96, respectively. The wireless communication ability is evaluated by the transmission coefficient, group delay, boresight gain, and received waveform. The calculated fidelity factor of the received waveform for the WBA and WRLBA is 0.79 and 0.85, respectively. The average and variations of the group delay of both wrapped antennas are observed to be around 2.5 ns and less than 1.5 ns, respectively.

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