Numerical method for full calculation of the electromagnetic field in a rectangular waveguide within overmoded configuration, using the fast Fourier transform

2014 ◽  
Vol 68 (2) ◽  
pp. 20501 ◽  
Author(s):  
Rui Prazeres
Keyword(s):  
Electromagnetic Field ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Numerical Method ◽  
Rectangular Waveguide ◽  
Full Calculation

Exact Green’s functions using leaking modes for axisymmetric boreholes in solid elastic media

Geophysics ◽  
1989 ◽  
Vol 54 (5) ◽  
pp. 609-620 ◽  
Author(s):  
R. A. W. Haddon
Keyword(s):  
Wave Propagation ◽  
Fourier Transform ◽  
Elastic Wave ◽  
Fast Fourier Transform ◽  
Numerical Method ◽  
Green's Functions ◽  
Green’S Functions ◽  
Elastic Media ◽  
Complex Frequency ◽  
Residue Theory

By choosing appropriate paths of integration in both the complex frequency ω and complex wavenumber k planes, exact Green’s functions for elastic wave propagation in axisymmetric fluid‐filled boreholes in solid elastic media are expressed completely as sums of modes. There are no contributions from branch line integrals. The integrations with respect to k are performed exactly using Cauchy residue theory. The remaining integrations with respect to ω are then carried out partly by using the fast Fourier transform (FFT) and partly by using another numerical method. Provided that the number of points in the FFT can be taken sufficiently large, there are no restrictions on distance. The method is fast, accurate, and easy to apply.

Analysis of Rubber Friction by the Fast Fourier Transform

1978 ◽  
Vol 6 (2) ◽  
pp. 89-113 ◽  
Author(s):  
R. A. Schapery
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Numerical Method ◽  
Plane Strain ◽  
Contact Problems ◽  
Fast Fourier Transform Algorithm ◽  
Periodic Arrays ◽  
Rubber Friction

Abstract A numerical method for solving contact problems is developed and then used to predict friction (without adhesion) between rubber in plane strain and periodic arrays of parabolic and triangular substrate asperities; the numerical method itself, which is based on the fast Fourier transform algorithm, is not limited to these asperity shapes. Also, effects of superposing two and more scales of texture are described. Some generalizations and related applications, such as analysis of tire traction, are then discussed.

Sign in / Sign up

Export Citation Format

Share Document