Numerical simulation of full-wave propagation in the time domain : an useful tool for underwater acoustic applications

2019 ◽  
Author(s):  
Paul Cristini
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Time Domain ◽  
Underwater Acoustic ◽  
Full Wave ◽  
The Time Domain

Time Domain Simulations on a Single Point Moored Submerged Sphere of Variable Radius

2005 ◽  
Author(s):  
Joa˜o M. B. P. Cruz ◽  
Anto´nio J. N. A. Sarmento
Keyword(s):  
Wave Propagation ◽  
Time Domain ◽  
Physical Phenomenon ◽  
Single Point ◽  
Vertical Direction ◽  
Equation Of Motion ◽  
Hydrodynamic Coefficients ◽  
Energy Converter ◽  
Submerged Sphere ◽  
The Time Domain

This paper presents a different approach to the work developed by Cruz and Sarmento (2005), where the same problem was studied in the frequency domain. It concerns the same sphere, connected to the seabed by a tension line (single point moored), that oscillates with respect to the vertical direction in the plane of wave propagation. The pulsating nature of the sphere is the basic physical phenomenon that allows the use of this model as a simulation of a floating wave energy converter. The hydrodynamic coefficients and diffraction forces presented in Linton (1991) and Lopes and Sarmento (2002) for a submerged sphere are used. The equation of motion in the angular direction is solved in the time domain without any assumption about its output, allowing comparisons with the previously obtained results.

Numerical Simulation by CGM for Moving Force Identification

2012 ◽  
Vol 238 ◽  
pp. 826-829
Author(s):  
Zhen Chen ◽  
Jun Ling Han
Keyword(s):  
Numerical Simulation ◽  
Time Domain ◽  
Bending Moment ◽  
Identification Accuracy ◽  
Time Varying ◽  
Acceptable Solution ◽  
Moving Force ◽  
Ill Posed ◽  
Simulation Results ◽  
The Time Domain

The conjugate gradient method (CGM) is compared with the time domain method (TDM) in the paper. The numerical simulation results show that the CGM have higher identification accuracy and robust noise immunity as well as producing an acceptable solution to ill-posed problems to some extent when they are used to identify the moving force. When the bending moment responses are used to identify the time-varying loads, the identification accuracy is more obviously improved than the TDM, which is more suitable for the time-varying loads identification.

scholarly journals Experimental and simulated milling stability tests

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 965-967
Author(s):  
Piotr Andrzej Bąk ◽  
Krzysztof Jemielniak
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Time Domain ◽  
Cutting Parameters ◽  
Milling Machine ◽  
Machined Surface ◽  
Simulation Results ◽  
The Stability ◽  
The Time Domain

Self-excited vibrations significantly reduce the milling productivity, deteriorate the quality of machined surface and tool life. One of the ways to avoid these vibrations is to modify the cutting parameters based on the stability analysis results. A method of numerical simulation of self-excited vibrations in the time domain can be used for this purpose. A comparison of numerical simulation results with those from experiments conducted using a milling machine is presented. The results confirm the correctness of applied modeling.

scholarly journals DYNAMICS OF AN ELASTIC AIRPLANE

Aviation ◽  
2005 ◽  
Vol 9 (1) ◽  
pp. 8-13
Author(s):  
Peter Chudý ◽  
Vladimír Daněk
Keyword(s):  
Numerical Simulation ◽  
Analytical Solution ◽  
Time Domain ◽  
Aerospace Engineering ◽  
Elastic Response ◽  
Elastic Model ◽  
The Past ◽  
University Of Technology ◽  
Complex Simulation ◽  
The Time Domain

This paper presents the work performed by the Institute of Aerospace Engineering at the Brno University of Technology. The purpose of the project was to compare the results obtained from classical analytical solutions and a complex numerical simulation of an airplane's aero elastic response. Compared to the analytical solution, which reduces the entire process to a straightforward manipulation with time‐proven graphs and tables, the numerical simulation offers a more complex description of the dynamic processes. A complex simulation, in contrast to the analytical solution providing us with only one estimated parameter, allows monitoring selected quantities in the time domain, thus giving us a tool for a visual qualification of the investigated process. In the past, dynamic aeroelastic properties were estimated utilizing simplified stick beam models. The desire for more complex aero elastic simulations led to the concept of the advanced aero elastic model, coupling advanced 3D structural FEM models with proven aerodynamic theory in the form of the DLM panel method.

Sign in / Sign up

Export Citation Format

Share Document