Simulation of Fluid Sloshing for Decreasing the Response of Structural Systems

2014 ◽  
Author(s):  
İlker Vuruşkan ◽  
Cüneyt Sert ◽  
Mehmet Bülent Özer
Keyword(s):  
Frequency Domain ◽  
Structural Model ◽  
Harmonic Component ◽  
Structural Response ◽  
Coupled System ◽  
Frequency Domain Analysis ◽  
Surface Shape ◽  
Structural Systems ◽  
Total Force ◽  
Ansys Fluent

In the last decade, there is a renewed interest in the integration of a sloshing tank into structural systems to decrease the vibrations of the structure. The purpose of this study is to try different numerical simulation programs for further use in studies in evaluation of the effectiveness of the sloshing tank absorbers for structural systems. The programs chosen for sloshing simulations are COMSOL Multiphysics®, ANSYS CFX and ANSYS-FLUENT. In the numerical simulations, the free surface shape during sloshing will be simulated under small and large amplitude sinusoidal displacements. The results obtained using different software will be compared with the results of the experiments reported in literature. Since the purpose is to use the sloshing forces on the container to decrease the structural response, the total force on the container walls is calculated and compared with the reported experimental results. The dynamics of a container coupled with the a structural model is simulated and forces applied on the container walls are analyzed in the frequency domain which is important in understanding the tuning of the vibration absorber. To the best of authors’ knowledge, in a fluid-structure coupled system the frequency domain analysis of the container wall forces at varying amplitudes of sinusoidal excitation is not presented in literature. The results showed even though higher harmonic forcing magnitudes increase with increasing base motion, the fundamental harmonic component does not change significantly.

On the Frequency Domain Analysis of Tire Relaxation Effects on Transient On-Center Vehicle Handling Performance

2009 ◽  
Author(s):  
Justin Sill ◽  
Beshah Ayalew
Keyword(s):  
Frequency Domain ◽  
Transfer Functions ◽  
Coupled System ◽  
Frequency Domain Analysis ◽  
Lateral Acceleration ◽  
Lateral Dynamics ◽  
Relaxation Effects ◽  
Lateral Vehicle Dynamics ◽  
Frequency Domain Approach ◽  
Two Degree Of Freedom

This paper presents an elegant frequency domain approach that can be used to analyze lateral vehicle dynamics for transient understeer and oversteer performance. Commonly used steady-state understeer analysis techniques are not able to expose some effects, such as tire relaxation, in on-center transient maneuvers. The approach presented here addresses such transient issues using a simple two degree of freedom handling model coupled to a model for tire lateral dynamics. In addition to the usual yaw rate and lateral acceleration transfer functions, this paper proposes using an understeer angle transfer function as an easy-to-interpret metric to evaluate transient on-center handling. Using the approach, it is shown that at low vehicle velocities, the inclusion of tire relaxation introduces dramatically different system dynamics by introducing highly undamped poles into the coupled system for both an understeering and an oversteering vehicle.

TIME-SEGMENTED FREQUENCY-DOMAIN ANALYSIS FOR NON-LINEAR MULTI-DEGREE-OF-FREEDOM STRUCTURAL SYSTEMS

2000 ◽  
Vol 237 (3) ◽  
pp. 457-475 ◽  
Author(s):  
W.J. MANSUR ◽  
J.A.M. CARRER ◽  
W.G. FERREIRA ◽  
A.M. CLARET DE GOUVEIA ◽  
F. VENANCIO-FILHO
Keyword(s):  
Frequency Domain ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Degree Of Freedom ◽  
Structural Systems ◽  
Non Linear

scholarly journals A phase-locked loop using ESO-based loop filter for grid-connected converter: performance analysis

2021 ◽  
Author(s):  
Baoling Guo ◽  
Seddik Bacha ◽  
Mazen Alamir ◽  
Julien Pouget
Keyword(s):  
Performance Analysis ◽  
Frequency Domain ◽  
Low Frequency ◽  
Experimental Tests ◽  
Frequency Measurement ◽  
Phase Locked Loop ◽  
Frequency Domain Analysis ◽  
Loop Filter ◽  
Control Stability ◽  
Unbalanced Grid

AbstractAn extended state observer (ESO)-based loop filter is designed for the phase-locked loop (PLL) involved in a disturbed grid-connected converter (GcC). This ESO-based design enhances the performances and robustness of the PLL, and, therefore, improves control performances of the disturbed GcCs. Besides, the ESO-based LF can be applied to PLLs with extra filters for abnormal grid conditions. The unbalanced grid is particularly taken into account for the performance analysis. A tuning approach based on the well-designed PI controller is discussed, which results in a fair comparison with conventional PI-type PLLs. The frequency domain properties are quantitatively analysed with respect to the control stability and the noises rejection. The frequency domain analysis and simulation results suggest that the performances of the generated ESO-based controllers are comparable to those of the PI control at low frequency, while have better ability to attenuate high-frequency measurement noises. The phase margin decreases slightly, but remains acceptable. Finally, experimental tests are conducted with a hybrid power hardware-in-the-loop benchmark, in which balanced/unbalanced cases are both explored. The obtained results prove the effectiveness of ESO-based PLLs when applied to the disturbed GcC.

scholarly journals Comparison of short-range order in irradiated dysprosium titanates

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Model ◽  
Ion Irradiation ◽  
Function Analysis ◽  
Ion Beam ◽  
Structural Response ◽  
Heavy Ion ◽  
Range Order ◽  
Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

scholarly journals Analysis of Three-Phase Wye-Delta Connected LLC

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3606
Author(s):  
Jing-Yuan Lin ◽  
Chuan-Ting Chen ◽  
Kuan-Hung Chen ◽  
Yi-Feng Lin
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Operation Time ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Complete Analysis ◽  
Plane Analysis ◽  
Analysis Methods ◽  
Three Phase

Three-phase wye–delta LLC topology is suitable for voltage step down and high output current, and has been used in the industry for some time, e.g., for server power and EV charger. However, no comprehensive circuit analysis has been performed for three-phase wye–delta LLC. This paper provides complete analysis methods for three-phase wye–delta LLC. The analysis methods include circuit operation, time domain analysis, frequency domain analysis, and state–plane analysis. Circuit operation helps determine the circuit composition and operation sequence. Time domain analysis helps understand the detail operation, equivalent circuit model, and circuit equation. Frequency domain analysis helps obtain the curve of the transfer function and assists in circuit design. State–plane analysis is used for optimal trajectory control (OTC). These analyses not only can calculate the voltage/current stress, but can also help design three-phase wye-delta connected LLC and provide the OTC control reference. In addition, this paper uses PSIM simulation to verify the correctness of analysis. At the end, a 5-kW three-phase wye–delta LLC prototype is realized. The specification of the prototype is a DC input voltage of 380 V and output voltage/current of 48 V/105 A. The peak efficiency is 96.57%.

scholarly journals Amplitude Design of Perturbation Signal in Frequency-Domain Analysis of Grid-Connected Systems

2020 ◽  
Vol 53 (2) ◽  
pp. 13161-13166
Author(s):  
Henrik Alenius ◽  
Roni Luhtala ◽  
Tomi Roinila
Keyword(s):  
Frequency Domain ◽  
Domain Analysis ◽  
Frequency Domain Analysis
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