scholarly journals Hybrid TE-TM scheme for time domain numerical calculations of wakefields in structures with walls of finite conductivity

2012 ◽  
Vol 15 (5) ◽  
Author(s):  
Andranik Tsakanian ◽  
Martin Dohlus ◽  
Igor Zagorodnov
Keyword(s):  
Time Domain ◽  
Numerical Calculations ◽  
Finite Conductivity

scholarly journals Frequency and Time Domain Analysis of Influence of the Grounding Electrode Conductivity on Induced Current Distribution

2013 ◽  
Vol 9 (2) ◽  
pp. 137 ◽  
Author(s):  
Silvestar Šesnić ◽  
Dragan Poljak
Keyword(s):  
Current Distribution ◽  
Time Domain ◽  
Current Source ◽  
Time Domain Analysis ◽  
Finite Conductivity ◽  
Significant Discrepancy ◽  
Electrode Current ◽  
Air Interface ◽  
Grounding Electrode ◽  
Time Domain Response

The paper deals with an assessment of the influence of finite conductivity to the current induced along the horizontal grounding electrode. Analysis is performed in frequency and time domain, respectively. Current distribution along the grounding electrode buried in a lossy half-space is determined via analytical solution of the corresponding Pocklington equation in the frequency domain. The corresponding time domain response is obtained by means of Inverse Fast Fourier Transform (IFFT). The electrode is excited via an equivalent current source. Presence of the earth-air interface is taken into account via the simplified reflection coefficient arising from the Modified Image Theory (MIT). The electrode current is calculated for the case of perfectly conducting (PEC) electrode and for the electrodes made of copper and aluminum. Comparison of results shows no significant discrepancy between these electrodes, justifying the use of a PEC electrode approximation.

Numerical Study on Sea Keeping Performances of Ship by Exact Linear 3-D Potential Method

2007 ◽  
Author(s):  
N. M. Golam Zakaria ◽  
M. S. Baree
Keyword(s):  
Frequency Domain ◽  
Wave Height ◽  
Time Domain ◽  
Domain Analysis ◽  
Potential Method ◽  
Frequency Domain Analysis ◽  
Numerical Calculations ◽  
Irregular Waves ◽  
Linear Potential ◽  
Time Domain Simulation

This paper deals with the numerical calculations of sea-keeping performances of ship in irregular sea condition. Here linear potential theory has been applied for describing the fluid motion and 3-D sink-source technique has been used to determine hydrodynamic forces for surface ship advancing in waves at constant forward speed. Numerical coding based on 3-D potential method has been tested in an extensive manner keeping an eye with the criteria recommended by various ITTC committees [1]. The numerical accuracy of the coding has been examined using some experiment results as well as some other contemporary numerical calculations given by some authors for the case of frequency domain analysis. Taking a typical Panamax Container Vessel and in order to simulate its sea-keeping performances in real sea condition, the frequency domain analysis has been performed. The result is then used for time domain simulation in short crested irregular waves. Unequal frequency spacing has been taken into account to get longer simulation time and also empirical nonlinear roll damping has been taken in the way of time domain simulation. From this time domain simulation, relative wave height has been calculated which could sometimes damage deck equipment as well as posing a risks to personnel in severe sea condition. The effect of speed & wave direction on relative wave height has been considered and finally the numerical results of the maximum and significant values of irregular relative wave heights for these conditions are discussed.

Seakeeping of a Non-Wall Sided Vessel in Shallow Water: Lessons Learnt From Experiments and Numerical Analyses

2007 ◽  
Author(s):  
Mamoun Naciri ◽  
Neil Southall
Keyword(s):  
Shallow Water ◽  
Time Domain ◽  
State Of The Art ◽  
Numerical Calculations ◽  
Numerical Analyses ◽  
Numerical Investigations ◽  
Numerical Predictions ◽  
Lessons Learnt ◽  
Nonlinear Potential

Extensive model tests of a soft moored LNG carrier in shallow water have been performed in 2004. The focus of this test campaign was on the hydrodynamics of non wall-sided, low drag vessels and the characterization of the model basin performance. The motivations behind this test campaign have been discussed in ref [1] and [2]. Numerical calculations have been performed using industry state of the art tools and compared to experiments. Having uncovered differences, further numerical investigations have been performed with a nonlinear potential time domain solver. Comparison between experiments and numerical predictions will be presented for monochromatic waves in 30m depth. Lessons learnt in the process will be highlighted.

Influence of intramolecular vibrations in third-order, time-domain resonant spectroscopies. II. Numerical calculations

2001 ◽  
Vol 114 (18) ◽  
pp. 8020-8039 ◽  
Author(s):  
Kaoru Ohta ◽  
Delmar S. Larsen ◽  
Mino Yang ◽  
Graham R. Fleming
Keyword(s):  
Time Domain ◽  
Numerical Calculations ◽  
Third Order ◽  
Intramolecular Vibrations
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