Effect of Porous Baffle on Sloshing Dynamics in a Barge Mounted Container Subjected to Wave Excitation

2017 ◽  
Author(s):  
Nasar Thuvanismail ◽  
Akshay P. Shah ◽  
Deepak J. Surahonne ◽  
Sannasiraj S. Annamalaisamy
Keyword(s):  
Experimental Investigation ◽  
Aspect Ratio ◽  
Water Level ◽  
Excitation Frequency ◽  
Experimental Setup ◽  
Regular Wave ◽  
Wave Excitation ◽  
Regular Waves ◽  
Sloshing Dynamics

An experimental investigation was carried out to determine the effect of porous baffle walls on sloshing dynamics of a sloshing tank that is partially filled with liquid and rigidly mounted in a barge. The experimental setup is subjected to beam sea regular wave excitations and hence the barge experiences combined sway heave and roll excitations. An aspect ratio (hs/l, where hs is still water level and l is length of tank) of 0.488 is considered which corresponds to 75% fill condition with respect to tank height. Three porosities of 15%, 20%, and 25% are considered. The barge system was subjected to regular waves of frequency (fw) ranging from 0.45Hz to 1.54Hz. The effectiveness of porous baffles on the dissipation of sloshing energy is studied in comparison with without baffle condition. The effect of wave excitation frequency on the sloshing dynamics has also been analysed and the prominent results are here in reported.

Experimental Investigation of Sloshing Dynamics Coupled With Barge Responses

2009 ◽  
Author(s):  
T. Nasar ◽  
S. A. Sannasiraj ◽  
V. Sundar
Keyword(s):  
Experimental Investigation ◽  
Wave Height ◽  
Natural Frequencies ◽  
Excitation Frequency ◽  
Wave Excitation ◽  
The Third ◽  
Sloshing Frequency ◽  
Sloshing Dynamics ◽  
Liquid Depth ◽  
Cover Up

An experimental work has been carried out to study the phenomena of sloshing of liquid in a partially filled tank with aspect ratio (hs/l, where hs is the static liquid depth and l is the tank length) of 0.585. The sloshing tank was rigidly fixed in to a barge and was exposed to regular beam waves. The wave excitation frequencies (fw) ranging from 0.70Hz to 1.54Hz that cover up to the third mode natural sloshing frequency (f3) are considered. The incident wave height (Hi) is 0.10m. The effects of wave excitation frequency and wave height on the sloshing oscillation are studied. Attempts are made to evaluate the harmonics present in the sloshing oscillation and compare with the results of earlier studies. The barge responses such as sway, heave and roll are measured and it is found that the barge responses at their natural frequencies are insensitive to induce sloshing oscillation inside the tank.

Experimental Investigation of Vortex-Induced Vibrations of a Flexibly Mounted Circular Cylinder in Combined Current and Wave Flows

2021 ◽  
Author(s):  
Pierre-Adrien Opinel ◽  
Narakorn Srinil
Keyword(s):  
Experimental Investigation ◽  
Circular Cylinder ◽  
Cross Flow ◽  
Wave Flow ◽  
Regular Wave ◽  
Regular Waves ◽  
Vortex Induced Vibrations ◽  
Flow Frequency ◽  
The Cross ◽  
Wave Flows

Abstract This paper presents the experimental investigation of vortex-induced vibrations (VIV) of a flexibly mounted circular cylinder in combined current and wave flows. The same experimental setup has previously been used in our previous study (OMAE2020-18161) on VIV in regular waves. The system comprises a pendulum-type vertical cylinder mounted on two-dimensional springs with equal stiffness in in-line and cross-flow directions. The mass ratio of the system is close to 3, the aspect ratio of the tested cylinder based on its submerged length is close to 27, and the damping in still water is around 3.4%. Three current velocities are considered in this study, namely 0.21 m/s, 0.29 m/s and 0.37 m/s, in combination with the generated regular waves. The cylinder motion is recorded using targets and two Qualisys cameras, and the water elevation is measured utilizing a wave probe. The covered ranges of Keulegan-Carpenter number KC are [9.6–35.4], [12.8–40.9] and [16.3–47.8], and the corresponding ranges of reduced velocity Vr are [8–16.3], [10.6–18.4] and [14–20.5] for the cases with current velocity of 0.21 m/s, 0.29 m/s and 0.37 m/s, respectively. The cylinder response amplitudes, trajectories and vibration frequencies are extracted from the recorded motion signals. In all cases the cylinder oscillates primarily at the flow frequency in the in-line direction, and the in-line VIV component additionally appears for the intermediate (0.29 m/s) and high (0.37 m/s) current velocities. The cross-flow oscillation frequency is principally at two or three times the flow frequency in the low current case, similar to what is observed in pure regular waves. For higher current velocities, the cross-flow frequency tends to lock-in with the system natural frequency, as in the steady flow case. The inline and cross-flow cylinder response amplitudes of the combined current and regular wave flow cases are eventually compared with the amplitudes from the pure current and pure regular wave flow cases.

Liquid Sloshing Dynamics in a Container Subjected to Coupled Mode Excitation

2008 ◽  
Author(s):  
T. Nasar ◽  
S. A. Sannasiraj ◽  
V. Sundar
Keyword(s):  
Excitation Frequency ◽  
Qualitative Assessment ◽  
Floating Body ◽  
Nonlinear Behaviour ◽  
Wave Excitation ◽  
Coupled Mode ◽  
Sloshing Dynamics ◽  
Time Histories ◽  
Fill Level ◽  
The Individual

An experimental work has been carried out to study the phenomena of sloshing of liquid in a partially filled tank mounted on a barge exposed to regular beam waves. Liquid fill level with aspect ratio (hs/l, where hs is the static liquid depth and l is the tank length) of 0.325 is studied. The time histories of sloshing oscillation are measured along the length of container at predefined locations. The nonlinear behaviour of sloshing oscillation is observed for the regular wave excitation. The spectra of the sloshing oscillation and their qualitative assessment are reported. The individual sway and heave analytical model have been studied in order to substantiate the importance of coupled mode of excitation. Attempts are made to evaluate the harmonics present in the sloshing oscillation and compare with the results of earlier studies. In the present interaction study, it was found that the nonlinear response of the floating body also plays a role to induce violent sloshing oscillation. The effects of wave excitation frequency on the sloshing oscillation are reported.

scholarly journals Liquid sloshing dynamics in a barge carrying container subjected to random wave excitation

2012 ◽  
Vol 9 (1) ◽  
pp. 43-65 ◽  
Author(s):  
Nasar Thuvanismail ◽  
Sannasiraj Sannasi ◽  
Sundar Vallam
Keyword(s):  
Excitation Frequency ◽  
Primary Resonance ◽  
Peak Frequency ◽  
Experimental Program ◽  
Random Wave ◽  
Wave Excitation ◽  
Excitation Peak ◽  
Sloshing Dynamics ◽  
Sloshing Mode ◽  
Marine Engineering

The sloshing phenomenon of liquid in a partially filled tank mounted rigidly on a barge exposed to random beam waves has been investigated through a well controlled experimental program. Four relative liquid depths, (liquid depth, hs/ length of tank, l) of 0.163, 0.325, 0.488 and 0.585 were considered for the tests. The sloshing oscillation was measured along the length of the tank at predefined locations. The effect of variation of the peak wave excitation frequency on the sloshing oscillation in the frequency domain is studied. The dominant energy is found to be concentrated around lowest nth sloshing mode frequency and, secondary peaks are observed at higher order sloshing frequencies. Odd modes contributions are dominating even modes irrespective of the excitation peak frequency. The sacrifice of second mode is observed while the excitation peak frequency is closer to its primary resonance. DOI: http://dx.doi.org/10.3329/jname.v9i1.7600 Journal of Naval Architecture and Marine Engineering 9(2012) 43-65

Experimental investigation on tilt stabilizing effect of external toroidal field in low aspect ratio tokamak

1997 ◽  
Vol 4 (2) ◽  
pp. 315-322 ◽  
Author(s):  
A. Morita ◽  
Y. Ono ◽  
M. Katsurai ◽  
M. Yamada ◽  
S. Yoshikawa
Keyword(s):  
Experimental Investigation ◽  
Aspect Ratio ◽  
Toroidal Field ◽  
Low Aspect Ratio ◽  
Stabilizing Effect

scholarly journals Fabrication of High Aspect Ratio Porous Microfeatures Using Hot Compaction Technique

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Peng Chen ◽  
Gap-Yong Kim ◽  
Jun Ni
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Heat Transfer Performance ◽  
Experimental Setup ◽  
Production Environment ◽  
Taper Angle ◽  
High Productivity ◽  
Powder Consolidation ◽  
Hot Compaction ◽  
High Temperature Operation

High aspect ratio porous microfeatures are becoming more important in the modern industry. However, the fabrication of such features under a mass production environment remains a challenge when robustness, cost effectiveness, and high productivity requirements are required. In this study, the forming of such porous microfeatures using hot compaction was investigated. A hot compaction experimental setup was designed and fabricated that is capable of performing high temperature operation (700°C), quick heatup, and avoiding oxidation. 3D thermal simulation of the experimental setup was conducted to investigate the heat transfer performance and internal temperature distribution, which was then used as a reference for the experiment. Hot compaction experiments were carried out, and the effects of compression force and temperature on the quality in terms of powder consolidation strength and porosity were investigated. In addition, the achievable aspect ratio and taper angle were also discussed.

scholarly journals BREAKWATER ARMOR DISPLACEMENT THRESHOLDS: A POSSIBLE CORRELATION WITH CUMULATIVE WAVE ENERGY

1984 ◽  
Vol 1 (19) ◽  
pp. 186
Author(s):  
Daniel L. Behnke ◽  
Frederic Raichlen
Keyword(s):  
Wave Energy ◽  
Wave Train ◽  
Wave Length ◽  
Simple Wave ◽  
Wave Theory ◽  
Irregular Waves ◽  
Reconstruction Technique ◽  
Regular Wave ◽  
Regular Waves ◽  
Three Dimensional Model

An extensive program of stability experiments in a highly detailed three-dimensional model has recently been completed to define a reconstruction technique for a damaged breakwater (Lillevang, Raichlen, Cox, and Behnke, 1984). Tests were conducted with both regular waves and irregular waves from various directions incident upon the breakwater. In comparison of the results of the regular wave tests to those of the irregular wave tests, a relation appeared to exist between breakwater damage and the accumulated energy to which the structure had been exposed. The energy delivered per wave is defined, as an approximation, as relating to the product of H2 and L, where H is the significant height of a train of irregular waves and L is the wave length at a selected depth, calculated according to small amplitude wave theory using a wave period corresponding to the peak energy of the spectrum. As applied in regular wave testing, H is the uniform wave height and L is that associated with the period of the simple wave train. The damage in the model due to regular waves and that caused by irregular waves has been related through the use of the cumulative wave energy contained in those waves which have an energy greater than a threshold value for the breakwater.

scholarly journals Experimental Investigation of a Nonlinear Energy Storage Effect due to High Power Electromagnetic Excitation

2020 ◽  
Vol 18 ◽  
pp. 75-82
Author(s):  
Robert Michels ◽  
Martin Schaarschmidt ◽  
Frank Gronwald
Keyword(s):  
Experimental Investigation ◽  
Energy Storage ◽  
Experimental Setup ◽  
Storage Effect ◽  
Nonlinear Circuit ◽  
Electromagnetic Excitation ◽  
Parameter Variations ◽  
Study Parameter ◽  
Loop Antennas ◽  
Nonlinear Energy

Abstract. The susceptibility of interference victims can significantly be influenced by the presence of nonlinear circuit elements. In addition to the well known occurrence of intermodulation-frequencies, other effects can be observed as well. Recently, a nonlinear energy storage effect has been discovered which is due to the presence of nonlinearly loaded loop antennas if excited by an HPEM-excitation. In this contribution, this effect is further studied by experiment. It is seen that the nonlinear energy storage effect can be reproduced by means of a rather simple experimental setup. This allows to straighforwardly study parameter variations in order to attain an improved understanding of the considered effect.

Sign in / Sign up

Export Citation Format

Share Document